Transcript for:
High-Yield Dermatology and Rheumatology Insights

all right if you're just joining us welcome i am so excited to get started in just a few minutes make sure that your chat box is set to panelists and attendees and i also put in the youtube live stream link so that we can blow this up on social media today it is going to be a very high yield session we're going to be covering a lot of material so make sure you have your hydration station right next to you and you also are ready to stay engaged cut out those distractions all right everyone if you do not mind please let me know in the chat box if you can see me and hear me loud and clear just want to make sure that the audio and visuals are ready to go awesome thank you so much for that feedback it seems like many people are uh looking at my face my slides as well as uh hearing me so i'm glad that uh it's working all right we'll get started in just a little bit awesome thank you all for changing the chat box feature to panelists and attendees and also thank you for saying hello we have people from ecuador maryland uh ohio uh india so keep them coming as you're logging in go ahead and just say hello i want everyone to connect with each other today and get a great high yield review we're going to get started in just a few minutes all right if you're just joining us welcome to the classroom today we are going to be covering dermatology and rheumatology there are still a couple people who are probably logging in so i will officially start in a few minutes but i just wanted to come in say hello make sure you guys can hear me see me also if you can see my slides go ahead and type in yes into the chat box as well as where you're logging in from i'm really excited to get started in just a little bit alrighty everyone welcome to today's step one review i am so excited each and every one of you are here thank you so much for joining it's just at the top of the hour and over the next hour hour and 15 minutes we are going to be going through the high-yield nvme concepts from both dermatology and rheumatology so you can kick ass on your usmle before i get started i wanted to give a brief overview for many of you this is going to be the first time for many of you this is going to be the first time you have joined one of my lectures and i want to thank you and welcome you with open arms i wanted to also introduce myself my name is rahul i am going into now my last year of pediatric critical care fellowship and over the past six years i have been absolutely passionate about helping students prepare for and excel on the usmle and i hope that that same passion will come across the screen today right in the comfort of your own study space and you will be able to really garner some high-yield nuggets so that it can help you in your preparation and answering these derm and room questions for those of you who have joined me along this journey i welcome you back thank you so much for making hi guru such an awesome experience for us all so i wanted to just start out if you are new especially and talk about what makes high group my passion project so unique and i know that there are so many other resources already out there one of the key things that i like to focus on is an evidence-based approach on test taking as well as preparing for the usmle i focus all of my lectures and you'll see that today on active recall we go through all of the organ systems and i'd like for you to kind of learn the concepts in a question-based way i also like to integrate material and so today yes it's going to be room and derm but what you'll realize is we'll put in a little bit of pulmonary we'll put in a little bit of heme and especially for rheumatology the name of the game is multi-system involvement and that's what's going to be seen on your exam questions as well finally i think one of my key passions is to really help students with test taking strategy and use an onion model approach hey how do i approach a test question well hint stem paraphrase and predict how do i go through a block i go through the block as a three pass approach how do i go through multiple blocks and finally how do i tackle test day i like to give students that strategic approach and you'll see that whether you work with me one-on-one or if you are going to be embarking on my courses so speaking of my triad and the methodology by which i go through usmla preparation i like to focus on three things the first thing that i like to focus on is content application and test taking strategy there are so many resources that that is going that is going to teach you the content but i think the name of the game and you know this as well is how do you apply that content and how do you have a strategic systematic approach that allows you to optimize your application skills the next thing that i like to focus on is productivity and scheduling i leverage this program called notion so that i can make a layered schedule for students that balances both questions and content and finally this is a new realm that i've kind of tapped into over the past year and that is test taking psychology i realized that not only is this a grind in terms of mental preparation and showing up every single day and doing questions doing practice exams but i realized that there is a huge psychological component and that psychological component needs to be addressed while you are preparing for the usmle and that is something that my energy really tries to focus on and i like to make sure that students are thinking in a very optimistic and positive outlook most importantly and we see that today with over a hundred people joining us today most importantly we are a community hi guru is an absolutely rocking community and i've been humbled to work to work with multiple medical schools across the country teaching live as well as online and it's been absolutely awesome to connect with students going through this journey especially during and after the pandemic we have really expanded our scope and we are now a global community of lifelong learners we have people today from india turkey ecuador ohio texas connecticut i mean this is absolutely awesome and i hope today in the chat box you'll be able to connect with everyone by turning your chat box from panelists to panelists and attendees and make sure you're typing out the answers to all of these active recall questions so what inspired me to create today's webinar as well as this whole nbme top concept series was a reddit post and reddit is awesome it has its pros and cons but a few months back there was a post that captured the most recurring concepts from the nbme practice exams and i kind of used that as a template and especially put in my own experience and my own acumen into these series of webinars and i really want to highlight the recurring concepts that you'll see along throughout all of your nbme practice exams and i organized it by organ systems and the check boxes indicate which we which organ systems we've already completed and so today we are going to be hitting up the msk derm and room section if you have not checked out my hundred concepts in gross anatomy review i really highly recommend it anatomy is one of those very challenging subjects for the usmle but i hope that that hour and a half review gives you the high yields that you need to know if you've missed my prior webinars don't worry i have them all recorded on my youtube channel and i have a whole playlist that basically has all 9 10 12 videos from the nbme top concepts series but wait there is absolutely more and my goal is to really provide you value and if you go to highguru.com not only are you going to be able to check out my courses but i also have put each of these lectures in a high quality bite-sized piece mode and essentially all of the videos are there absolutely for free you just have to log in with your with your email and you will be able to go through each and every organ system in a very active recall way which is which is absolutely phenomenal so make sure you definitely check that out again it's like totally totally free and my goal is to help students with us mla preparation and i hope that this provides you value in your journey so without further ado i appreciate you guys uh being a part of this introduction but most importantly please go ahead and open up the chat box right now and type in a yes or no if you are ready to go ahead and get started are you guys ready today all right we have some enthusiastic yeses make sure that you have your chat box to panelists and attendees and i want to give you guys one disclaimer i only asked for about an hour of your time today go ahead and mute your phone turn off all those notifications don't play this as background noise i want you to stay active and engage really i have made so many active recall questions so you should be at the edge of your seat and we will be covering a lot of high-yield material today so let's go ahead the bollywood in me is pumped as well let's go ahead and go through a little bit of an overview so what we are going to be doing today is covering some major topics and that is number one starting with neuromuscular junction disorders we're going to be talking about myasthenia gravis lambart eaton syndrome i'm then going to transition into a high-yield derm concept and that is comparing and contrasting bolus pemphigoid and pemphigus vulgaris hint hint remember that the characteristics of these bullet are grossly different we're going to be talking about skin cancer focusing on squamous cell basal cell as well as melanoma and then do another compare and contrast related to rheumatoid and osteoarthritis remember both of those are going to present as joint pain in your exam questions we're going to be going through the seronegative spondyloarthropathies and they are mostly related to the class 1 mhc which is hla b27 and i want you guys to really recognize that with these zero negative spondyloarthropathies they're usually going to be rheumatoid factor negative we're also going to be covering a awesome house concept which is the show tv show on fox house it's always lupus we're going to be covering lupus and i want you to really recognize that lupus has some systemic manifestations and that's why more than one question on your usmle exam can be related to lupus and then finally we are going to be crushing it today with a high-yield review of all of the antibodies that you will see so we will start with myasthenia gravis go into anti-smooth muscle with auto immune hepatitis so you're going to be having a great rapid review and then at the end i will be addressing all of your questions so make sure you save your questions write them down and we will have a live q a and i'll be trying to clear some of the doubts which you may have all right so let's go ahead and get started with our first concept today and that is talking about neuromuscular junction disorders so let's start with this question a patient presents with difficulty chewing and dysarthria she notices that at the end of her day and her eyes droop at the end of the day as well she attributes this eyelid drooping to generalize tiredness on exam she is noted to have blurry vision when asked to look to the left for a few minutes administration of an acetylcholinesterase inhibitor improves her symptoms the mechanism of this disease is most likely which pathology the mechanism of this disease is most likely like which pathology a atopic dermatitis b good pasture syndrome c rp gn or d contact dermatitis go ahead and type in the chat what you think the answer is awesome we're just getting warmed up today and so essentially this vignette is talking about myasthenia gravis and remember that myasthenia gravis is going to be a disorder in which you are going to get weakness that worsens with activity and this is due to a type 2 hypersensitivity reaction where you have auto antibodies to the postsynaptic nicotinic acetylcholine receptor and so because it's a type 2 hypersensitivity reaction this question really is going to test your knowledge on if you can recall another type 2 hypersensitivity reaction and that is going to be good pasture syndrome which we're going to be covering again but remember that good pasture syndrome has both hemoptysis which is coughing up blood in your test questions as well as hematuria which usually presents as a glomerular nephritis so what we're going to do now is we're going to be talking about myasthenia gravis and contrasting it with lambart eaton myasthenic syndrome so myasthenia gravis is like i mentioned a postsynaptic targeting of the acetylcholine receptors now remember these are primarily nicotinic acetylcholine receptors and nicotinic acetylchorine receptors are going to be ion channels and that's really high yield for you to know because muscarinic receptors are usually going to be g protein coupled receptors now myosin or gravis affects the neuromuscular junction but it also is going to have characteristic bulbar symptoms so what are bulbar symptoms those are the things in your exam questions that are related to cranial nerves so they're going to have ptosis they're going to have issues with extraocular muscles swallowing all of the functions that cranial nerves do that's what you're going to see impaired in myosin or gravis especially compared to lambar eating remember that the weakness is going to be worse at the end of the day because you are now at the end of the day not going to be having the packets of acetylcholine you're going to have those antibodies that are going to perpetuate the weakness and finally you need to understand that myasthenia gravis is associated with the thymomas it is actually thought that thymomas can have the actual auto antibodies to those acetylcholine receptors now how can they test this on the usmle well especially in step 2 ck they can say hey you can get an x-ray of the chest or a ct of this chest after you've diagnosed myasthenia gravis in order for you to assess for a thymoma let's go ahead and contrast that with lambart eaton syndrome now lambar eaton syndrome is more presynaptic and essentially it targets the presynaptic voltage-gated calcium channels if we look at the pre-synaptic terminal in order for you to release the acetylcholine packet you need those voltage-gated calcium channels to cause an influx of calcium into the pre-synaptic terminal and then bam get that acetylcholine in the neuromuscular junction however in lambar eaton you have actual antibodies to those presynaptic voltage-gated calcium channels now this ends up creating a different type of weakness and that is this proximal limb weakness as well as absent reflexes that improve upon repeated muscle stimulation i.e if you keep causing an action potential to go down that presynaptic nerve terminal you are going to overpower those antibodies with those zaps and your weakness is going to improve with activity that was the opposite case in myasthenia gravis and remember that lambart eaton is associated with a different type of chess pathology and that is going to be small cell lung cancer now speaking of small cell lung cancer what are some other associations specifically perineal plastic associations with small cell lung cancer well you got lambar eaten you have si adh and then you can have a cushing syndrome as well due to a perineal plastic acth secretion the key for us to recognize is that the class of medications are going to be these stigmins and we use these stigmans primarily for myosin or gravis i.e if the patient has weakness that improves with the administration of the stigmas which are acetylcholinesterase inhibitors you are going to be thinking more of myasthenia gravis all right let's keep going with another question a 40 year old male presents with weakness more prominent in the lower extremities he also is noted to have issues with incontinence and achieving erections his muscle myography is noted for an incremental increase in muscle contraction given this presentation which of the following studies may be abnormal in this patient so pay attention to the weakness itself and what's very characteristic of this vignette is the fact that there's some autonomic dysfunction and this autonomic dysfunction is actually also characteristic of this pathology which is the lambart eaton myasthenic syndrome so as you notice the muscle contraction improves with repeated stimulation and you want to think about the underlying small cell lung cancer and so that's why a ct of the chest may be an abnormal marker so what i also like to do is essentially give you a mental model on how i think about neuromuscular disorders so let's first off orient ourselves we can see here that this is the spinal cord and remember that you have upper motor neuron here you have lower motor neuron which is going to be here in the ventral horn this is going to be your peripheral nerve coming out and then this is your neuromuscular junction now we talked about myasthenia gravis lambar eaton remember that organophosphate poisoning can also affect the neuromuscular junction as well as botulism as you're going to inhibit the presynaptic activity of the snare proteins but you want to have this schema in your mind because for example upper motor neuron pathologies on the usmle can be related to damage to the corticospinal tract which you see in vitamin b12 deficiency you also see it in als and so remember that whenever you have upper motor neuron damage you're going to be having on your physical exam wordings such as hyperreflexia or clonus or babinski sine positive now you're going to contrast that with lower motor neuron lesions and lower motor neuron lesions are going to be things like spinal muscular atrophy polio virus and also als and so this is something that i want to pause and talk about and that is that lou gehrig's disease or amylotrophic lateral sclerosis is going to have both upper motor neuron signs and lower motor neuron signs on your exam so they'll have weakness fasciculations atrophy as well as then your upper motor neuron signs which are going to be babinski clonus etc so very important for us to just have that schema in our mind other important points that i want you to recognize is that the nerve that is going out to the muscle can be demyelinated and we see that in diabetes when you have non-enzymatic glycosylation due to the increased amount of sugar that is in your body as well as guillain-barre which is going to be a demyelinating condition that is specifically going to affect the schwann cells and hey let's do a little bit of integration right there remember that schwann cells are going to be derived from embryologically neural crest cells so what are some closing points from this slide well we got to know that organophosphate poisoning is going to have increased activity and i.e increased inhibition of acetylcholinesterase so basically what happens here is that you have increased activity of acetylcholine and you have inhibition of acetylcholinesterase so if you can't break down acetylcholine you're going to have high amount of acetylcholine so remember that these patients are going to be for example bradycardic they're going to have a lot of secretions and you're going to watch for a pesticide exposure and that's where a lot of the organophosphates are remember that you can use atropine to reverse this toxidrome finally we got to think about botulism and especially infantile botulism is rampant on the us othelli and that typically presents as hypotonia as well as constipation because remember you have a decrease of release of the acetylcholine and that's why you're not going to have good peristalsis in the gut our next section is going to be talking about bullish diseases but i want to pause right here go ahead if you're paying attention right now go ahead and type in the chat are you guys learning something yes or no give me a yes or no in the chat all right sudraja moshe georgies yash paulina wow we got a lot of people on today and i really appreciate you guys tuning in the next section we are going to be going through is bolus diseases so bullish diseases on your us emily they can give either a multimedia image or they can actually describe the bulla especially in the physical exam and the two bullish diseases that i want to bring up today are bolus pemphigoid and pemphigus vulgaris so let's talk about bullish pentagon in your exam questions you have to understand the pathophysiologic mechanism and that is that there are antibodies to the hemidesmosomes i eat the basal layer of your skin cells so the hemidesmosomes are going to be at that basal layer as a result you are going to have very very tense tense blisters because you are going to have many cells that will stack up right here and it is that basal layer that is affected and you're going to have these tense blisters that are what we call nikolski sine negative which means that if you are going to put pressure on those blisters they are still going to be nice taught and tense they're not going to explode bullish penthoid also is going to be uh described in your history as pruritic and characteristically you're going to have limited oral involvement and that's different than pemphigus bulgaris also what you need to recognize is that you have immune deposition especially along that dermal epidermal junction and so if they give you an immunofluorescence which we will see in our upcoming slides you have to recognize that linear appearance and that is going to be at that dermal epidermal junction now contrast this with pemphigus vulgaris when you're thinking about pemphigus vulgaris remember that these are antibodies to the desmosomes and remember desmosomes are these intercellular connections right here in between the cells so you separate all of these cells together well obviously the integrity is going to be weak and so you're going to have these flaccid blisters that are going to explode when you just have a quick little uh push on those blisters and that's what we call necosin positive now i do want to let you know that nikolski sign positive is just the physical exam maneuver so there are other bullish diseases or bullets like diseases for example toxic shock syndrome or staph scalded skin syndrome in which you will still have nicolsky sign positivity now pemphigus vulgaris characteristically has oral involvement so remember that you say vulgar things from your mouth and so that tells me ah that pemphigus vulgaris has the oral involvement in exam questions you may see this term acantholysis which basically represents a loss of intracellular connections and rather than a linear pattern you'll have more of a net like pattern on immunofluorescence so my key test taking strategy here is watch for the characteristic physical exam findings of the bulla and whether or not they're nikolski uh positive or nikolski negative so as you can see a picture a which is going to be on your left side that is going to represent your bullish pemphigoid and the b as you can see there is going to be more immunofluorescence and it is going to be in this net like pattern that is going to be more of your pemphigus vulgaris okay excellent let's go ahead and go through this next question a 30 year old male presents with a bloody cough so he has hemoptysis he recently traveled to northern africa however he states that even prior to his trip he had similar symptoms he undergoes pft testing which is notable for an increased dlco and his labs are notable for an elevated creatinine and crp as you can see there's a lot of inflammation many different organ systems are going to be involved which of the following antibodies may also be positive on laboratory testing why don't you go ahead and put this answer into the chat a topoisomerase one b cardiolype and phospholipid c double stranded dna or d collagen type four and many people are putting in collagen type four and you're absolutely correct if you're thinking about good pasture syndrome remember good pasture syndrome is this hemoptysis as well as hematuria which can present as a glomerulonephritis you have increased dlco because if you have a lot of actual hemoglobin within the alveoli because you have obviously hemoptysis you're gonna have better diffusing capacity of carbon monoxide because there are more trucks that will be able to carry the co which we test with remember that patients with good pastor syndrome are going to have hemoptysis and hematuria and that is going to be the differential which i want you to create and integrate for your usmle exam so let's go ahead and talk about hemoptysis and hematuria remember in your exam questions they're gonna have bloody cough as well as bloody urine so watch for the ua that they give a little bit of three plus protein or uh hematuria in so we talked about good pasture we need to also integrate microscopic polyangitis as well as granulomatosis with polyangiitis formerly known as wagner's disease now specifically talking about good pastures it's a type 2 hypersensitivity reaction and you have anti-glomerular basement membrane antibodies and remember the glomerular basement membrane is made up of type 4 collagen mpa is going to be p enco positive and that is typically going to be precipitated by drugs or infection what you have to understand is that this is a vasculitis so you're gonna have many organs messed up why is that well vasculitis it's a blood vessel and remember blood vessels perfuse organs so if if you have inflammation of the blood vessel that is going to perfuse that organ well the organ can get damaged because you have vascular inflammation remember that mpa is p enco positive and pi inca stands for myeloperoxidase very high yield for us to know now wegener's disease or granulomatosis with polyangitis also is going to have hemoptysis and hematuria but you're going to add the chronic sinusitis and it is going to be c anchor positive so along with mpa you are going to be integrating church strauss disease and the similarities that you will see in both of these is that both of them stain positive for mpo or p inca however church strauss has three things asthma eosinophilia and granulomas and that's how you can distinguish it from microscopic polyangitis next question a 40 year old female presents with the new onset rash she has a history of diarrhea gas and weight loss which she attributed to quote irritable bowels shows a vesicular rash in the extensor distribution she is scheduled to undergo endoscopy which of the following histopathological findings may be present upon biopsy so if we think about this presentation you have gi involvement plus a skin lesion and any time i think of something vesicular i always think of the word herpetic because herpes is classically going to be vesicular this is herpes like and this is the diagnosis of dermatitis herpetiformis and with the gi involvement you're thinking about celiac disease and with celiac disease you are going to see intra-intestinal epithelial lymphocytes with villus atrophy and that's important for us to recognize now what i want you to really integrate here is the fact that dietary modification can help with this rash and so this can be a part b question that they can put on your exam but the key is for us to recognize celiac dermatitis or pediformis and this sensitivity to gluten and that's important for us to note so this is a pathophysiology breakdown and how i look at celiac disease specifically for the usmlu remember that the pathophysiology is that normally when we eat gluten i.e carbs we end up releasing tissue transglutaminase and tissue transglutaminase modifies gliadin however in celiac disease you have t cells that are actually activated by this modified gliadin oh my gosh and that ends up giving us this crypt hyperplasia and villus atrophy i.e you get epithelial damage of the small intestine in particular now the dermatological correlate is dermatitis and prediformus and remember you need to watch out for especially in young children this stigmata affair to thrive and how do they put that in the u.s emily they basically put that the child has bad gross percentiles remember that dermatitis herpetiformis is itchy and it is classically herpes-like herpetiformis so you will see vesicles and this will be primarily on the extensor surfaces as you can see in the picture the diagnostic features for celiac disease in particular is anti-endomesial antibodies as well as anti-iga tissue transgutaminase now high yield for us to know let's think about this is that celiac disease is also associated with iga deficiency so this can give you a false negative especially if you have iga deficiency the anti-iga ttg may be falsely negative that's important for us to recognize so how does iga deficiency present on the usmle well what's important for us to understand is that iga is going to coat our mucosal surfaces so it typically presents as recurrent sinopulmonary infections but uniquely iga deficiency also presents as anaphylaxis to blood transfusions and i think that that is really a high-yield vignette for you to burn into your mind so remember that celiac disease it causes you to have malabsorption specifically of adenk and we just talked about iga deficiency so we've talked a lot about hypersensitivities and i wanted to integrate today some important hypersensitivities and mechanisms for your us emily now as you can see in the first column we're going to be going through the hypersensitivities we're going to be integrating the mechanisms and then what i think is high yield for the usmling itself so let's go through this type 1 hypersensitivity you're going to be thinking about ige mast cells basophils this is all about anaphylaxis eczema as well as allergies remember that there is going to be a high histamine load in type 1 hypersensitivity reactions type 2 hypersensitivity reactions is all about attacking your own body whether that's igm or igg auto antibody mediated and so we talked about things like celiac disease good pastures as well as autoimmune hemolytic anemia remember cold autoimmune hemolytic anemia is going to be igm whereas warm is going to be igg and characteristically in your exam questions the coombs is going to be positive type 3 hypersensitivity reactions it are going to relate to antibody antibody complexes or excuse me antigen antibody complexes and that activates complement and i can't i can't stress that enough that in type 3 hypersensitivity reactions because you have that immune complex deposition you are going to be consuming your complement now you're going to be thinking about this with serum sickness which is a vignette in which you have a penicillin or some sort of drug exposure two weeks later you have joint pain and low complement you're going to be thinking about that in lupus as well as in post-streptococcal glomerulonephritis type 4 hypersensitivities are t-cell mediad and they are what we call the delayed type hypersensitivity reactions and essentially what you have to integrate here are the vignettes related to a ppd test as well as contact dermatitis and so they can say that oh the patient ended up having jewelry that was purchased and it then started having a rash where that jewelry is located or they can be talking about a wooded area and then you have a vesicular rash that is more in a linear streak and that's where they're going for poison ivy poison ivy is also going to be a type 4 hypersensitivity reaction all right the next portion of this is going to be covering skin cancers let's go ahead and give a broad overview of skin cancers but first we will talk a little bit about test taking strategy when i think about dermatological lesions especially skin cancers i always look in usmle questions for the location of the rash and especially when you're talking about basal cell or squamous cell or precursor lesions you want to look for x sun exposed area so that's going to be the the lips the back of the neck etc maybe they're going to have some sort of occupation in which they are outside more so construction workers farmers etc what we also have to look for especially when you're talking about melanoma and rashes in general is you want to go through this abcde mnemonic and as you can see in this skin lesion which is melanoma you see asymmetry especially when you bisect the skin lesion you see border irregularities which they can put on physical exam and uneven appearance you see different colors i.e some are more hyper pigmented this outskirts are going to be hypo pigmented they're going to be large in diameter and they're going to be evolving lesions changing in size you want to be thinking hey histologically or from a cellular level they are going to be proliferating more so when i talk about malignant lesions you have to go back to chapters one through three of pathomo and that is integrating the principles of neoplasia in your vignette especially on histological uh exam they will write words such as hey the cells have disorganized growth or there is nuclear pleomorphism and hyperchromasia especially high yield for us to know is this high nuclear to cytoplasmic ratio and not only are you going to see this in skin cancers but you may see this in for example hematology when you're talking about leukemias remember blasts have very very big nuclei subsequently you're going to be thinking about these cells having a high mycotic activity as well as invasion of the basement membrane tells us that this neoplastic lesion is actually pretty malignant because it's invading structures and especially when it comes to skin cancer you will have that vertical growth phase related to melanoma for example and they will say hey tumor cells are embedded within the dermis which means that they actually broke through the basement membrane of the epithelial layer so zooming into this a little bit we see that there are prominent nucleoli in this lesion you see that there is going to be a high end to see ratio you see many mitosis in the actual picture and all of this should tell you in the exam question that hey we're dealing with the neoplasia now so when we talk about skin cancers there are three high-yield skin cancers that i want you guys to highlight number one we're going to be talking about squamous cell carcinoma number two we're going to be talking about basal cell carcinoma and number three we're going to be talking about melanoma which we already did a brief overview of so let's attack the first one let's go ahead and do this question so a farmer presents with several scaly lesions on the forehead he is noted to have a rough grainy texture on palpation of these skin lesions he undergoes biopsy which is consistent with neoplasia as this report reveals quote atypical keratinocytes confined to the basement membrane the patient is most likely going to be at risk for which of the following conditions a capocity sarcoma b melanoma c dermatoma d psoriasis or e squamous all carcinoma and so if we think about this specific question this diagnosis in this question is going to be actinic keratosis and actinic keratosis serves to be a precursor to squamous cell carcinoma now what i like to say is that actinic keratosis acts like squamous cell carcinoma and remember that it's a flaky scaly type rash and so actinic keratosis this is going to be those flaky scaly lesions remember they're going to be in sun exposed areas and so then that can progress to squamous cell carcinoma which is characterized by not only the scaliness but also ulceration which means that oh man that now we're talking about invasive squamous cell carcinoma typically what you want to do and this is just me integrating pharmacology is you want to recognize actinic keratosis and you want to act on it by kind of decreasing the neoplasia that can be seen when you're progressing to squamous cell carcinoma and so you do that by giving topical 5-fu and five flora uracil is an anti-metabolite that inhibits dimethylate synthetase and as a result you inhibit the conversion from d ump to dtmp and remember that these are going to be your dna precursors what other agent acts in this pathway well things like methotrexate also acts in this pathway so the goal when you're talking about neoplasia and a lot of these chemotherapeutics do it is to modulate or destroy dna especially of the cancer cells and that's why you can kind of suppress the or that's how you can suppress the neoplasia so let's go ahead and recap squamous cell carcinoma for the usmle the risk factors in exam questions is the fact that you're going to have uv exposure sun exposure and remember very important for us to integrate some biochemistry here that uvb light is going to create diamond dimers and what we also have to understand is that nucleotide excision repair is going to be crucial in repairing these diamond in dimers now location for squamous cell carcinoma it's going to be primarily on the lower lip but this is characteristic basal cells on the upper lip lower lip is squamous cell and you can remember bs as the mnemonic there typically you're going to see ulceration but i do want to highlight this important part and that is watching for a burn or a chronic draining sinus remember that if you have a wound that is not healing that wound is constantly going to be irritated and remember the wound is lined with squamous cells so if you keep irritating those squamous cells they can actually turn into neoplasia and that is why we think about chronic draining sinuses that especially ulcerate or on histopathology are going to have signs of neoplasia being related to squamous cell carcinoma of the skin histological features are the fact that you are going to have keratin pearls which you can see here as well as intracellular bridges and this is a hallmark for squamous lesions you're also going to have the background rhetoric of neoplasia which we already highlighted and then finally what got us into this mess of talking with squamous cell carcinoma is actinic keratosis actinic keratosis acts like squamous cell carcinoma of the skin it's a precursor lesion so moving on with skin cancers let's go ahead and do some active recall questions what is the most common malignant skin tumor and that is going to be actually basal cell carcinoma now basal cell carcinoma is going to be one of your most common cancers that's really important for us to recognize and what anatomical lesion does it professionally uh preferentially excuse me effect and that is going to be that upper lip which we talked about as well as the inner canthus of the eye and it also has an association with sun exposed areas so let's go through this practice vignette a 59 year old male presents with a raised papule on the upper surface of his lip so we're thinking basal cell carcinoma the sides of the crater-like lesion has multiple spiraled blood vessels and i think that this is important because on gross pathology you see many blood vessels within that raised lesion and so what may histo histological biopsy of the lesion reveal well typically what you will see is that you will see this basophilic or purplish staining of dysplastic basal cells in the underlying dermis and as you can see these are these palisading neoplastic cells that are going to be deeper in the dermis and i like to say that basal cell you have blue balls within the dermis so that tells us that there's a thick basophilic neoplastic proliferation so basal cell carcinoma of the skin the risk factors again just like squamous cell uv exposure location is going to be a little bit different remember the upper lip and you notice that it's a nodular experi appearance with blood vessels and remember that if they ask you the cellular level of this that is related to increased vegf and basal cell carcinoma actually rarely metastasizes and histologically you will see lesions within the inner dermis other associations is that basal cell carcinoma melanoma as well are associated with xeroderma pigmentosum so let's go ahead and talk a little bit about xeroderma pigmentosum and how it presents on the usmle again what i like to do is i like to kind of flow you through all of these high-yield concepts and put them together in a fun energetic integrative way so that you are able to really think on your feet and and learn this information conceptually so here you have a four-year-old male who presents to the dermatology clinic for a recurrent skin rash despite being inside for majority of the year the child is noted to have a sunburn like rash that consistently waxes and wanes the mother recalls that her uncle had similar sunburn issues and died from melanoma so you're thinking that this is something hereditary physical exams show skin atrophy and on the neck and hands there are three nevi which are enlarging rapidly which of the following is the most likely mechanism behind the pathology so xeroderma pigmentosum it's hereditary you notice that there is a hypersensitivity of the skin and this is related to nucleotide excision repair that is defective in these patients let's go ahead and do another question here a patient presents with a skin rash that has been having irregular borders a biopsy is taken and is notable for a b raft mutation which of the following is the most likely diagnosis so irregular borders that clues you into some sort of melanoma and b raf is also associated the mutation itself is associated with melanoma so you get unchecked or increased amounts of dna proliferation when you have a b raft mutation now i totally get that many of you look at these questions they're like i want to get it right i want to get it right i want to get it right i want to get it right but it's not just about the right answers and i wanted you to really recognize that as you're going through your preparation it is about making sure that the process to how you get to correct answers is more important and that's why we want to take our focus away from three-digit scores and u-world practice uh percentages we want to really focus on the process and that's why test-taking strategy is so crucial let's talk a little bit about melanoma risk factors and exam questions again you're going to be thinking about light exposure as well as dysplastic nevir these moles that are going to have a increased proliferation the location of melanoma typically is going to be having the abcd appearance but also think about this form of melanoma which is acrylintiginous which affects the palms and souls and integumentary system of the hands and limbs what you also have to understand is that patients with melanoma are going to manifest on your exam in a metastatic way so especially if you see a patient who has for example nuanced seizures and then they give you an mri or a ct and you see multiple lesions anytime i see multiple lesions on gross pathology or radiography on the usmle i think of metastasis and melanoma notoriously can metastasize to brain liver and lung and remember that they the mutation is the braf mutation and you have high nuclear dna replication and a farm integration is that the murafinib is going to be a b-raf kinase inhibitor all right very good a 27-year-old caucasian female presents with weight loss as well as weakness she feels very dizzy and lightheaded physical exam reveals several areas of her skin including her elbows and knees more tan i.e there's more hyperpigmentation with these constitutional symptoms the cells which are stimulated are derived from which embryological layer and so you notice that this is a unique question which tests you on hyperpigmentation melanocytes as well as embryological derivatives and you're thinking about yes you got it neural crest and this is going to be what presentation this is going to be addison's disease and addison's disease you're going to have signs and symptoms of salt wasting and hyperpigmentation we need to understand the mechanism behind that i.e this is primary adrenal insufficiency remember that in order for you to get in primary adrenal insufficiency in order for you to get acth you are going to need a precursor molecule synthesizing the hypothalamus known as pomc so remember that when your adrenal cortex is going to be down ac th is going to stimulate it from above that's just normal feedback mechanisms and in order for us to have acth you're going to as a byproduct be secreting more pomc as well as most importantly more beta endorphins and melanocyte stimulating hormone and so palm c very high yield is the precursor for not only acti but also msh and endorphins so when patients are going to have high acth levels they can also have increased melanocyte stimulation what i also want to do is integrate for you all the neural crest derivatives and i use the mnemonic motel pass now remember the neural crest embryologically is going to be when you are just about to make the neural tube and the neural tube gives rise to the brain and the spinal cord but the neural crest is right before you form the neural tube and afterwards you have these neural crest cells that end up giving you adult derivatives so m is going to stand for melanocytes o is going to be odontoblast remember they make the dentin which is in your teeth right underneath the enamel t is going to be tracheal cartilage and l is going to be laryngeal cartilage both the tracheal and laryngeal cartilage is going to be derived from neural crest enterochromafin-like cells are also derived from neural crest so what questions are you going to get from that well remember that ecl cells are going to secrete histamine in the gi tract and that ends up being one of the mediators that cause you to secrete acid p is going to be related to parafollicular c cells of the thyroid what hormone do the parafollicular c cells of the thyroid secrete go ahead and put that into the chat the parafollicular c cells of the thyroid are going to secrete and many of you are putting that in the chat you got it calcitonin very important for us to know that tumors derived from the parafollicular c cells are known as medullary carcinoma of the thyroid and that can be also seen in men syndromes for your endocrine time a is going to be related to all ganglia as well as the adrenal medulla remember the adrenal medulla makes epinephrine and norepinephrine and a unique question that they can give related to all ganglia is the fact that ah the dorsal root ganglion is going to be neural crest derived and that herpes simplex virus actually is going to hide in the dorsal root ganglion schwann cells which myelinate the pns remember those are going to be implicated when we talk about guillain-barre and then the aortic pulmonary septum and so that's why when you have defects in septal or septum development i.e neural crest migration you are going to have issues that can lead you to things like truncus arteriosus or tetralogy of flow another all ganglia question is going to be related to hershbrunn's disease and remember that you have the hourbox myenteric plexus that is derived from neural crest cells and that abnormal neural crest migration can be implicated in hershbung's disease so let's talk a little bit about melanin itself and when you're talking about melanin we want to review some biochemistry what amino acid is the precursor to melanin and that is going to be tyrosine now remember that phenylalanine upstream is the precursor to tyrosine so there is a biochemical integration here and there is a pathology that is related to the lack of the enzyme i.e phenylalanine hydroxylase which converts phenylalanine to tyrosine and that's known as pku and typically these patients have this characteristic musty mossy body odor but they have pale fair skin why because you don't have good tyrosine and downstream you don't have good melanin so it is always important for us to integrate the phenylalanine to tyrosine that's pah tyrosine is then going to get converted into dopa related to tyrosine hydroxylase and melanin is going to kind of be in this area right here thyroid hormone is here melanin is going to be here okay dopa gets converted into dopamine via dopa decarboxylase so this is where your basal ganglia questions can come in related to parkinson's dopamine can be converted into norepinephrine which is your catecholamines and when you methylate a norepinephrine ie you have s methyltransferase you are going to then make epinephrine and these are going to be the byproducts of the adrenal medulla and watch out these can be obviously elevated when you have theochromocytomas all right next topic we are going to be covering rheumatoid arthritis versus osteoarthritis we are moving really well through this review let's go ahead and pause right now let's all take a deep breath go ahead just take a nice slow deep breath just do it i know it's weird all right let's go ahead and get started rheumatoid arthritis versus osteoarthritis for your us emily what i first want to do is i want to give you a big picture overview and that is that you need to look at the big picture rheumatoid arthritis in your test questions you are going to have very systemic symptoms high yield for you to know that systemic symptoms means that you're gonna have a lot of inflammation fevers elevated esr elevated crp you're gonna get a lot of joint stiffness because once you have a calming down of that systemic inflammation you're going to form crystalline arthropathies kind of like your joints end up being coming very tight tight tight contrast that with osteoarthritis osteoarthritis is wear and tear bone on bone you'll see this in for example obese patients it's going to be worse at the end of the day because you're on your weight-bearing surfaces all throughout the day you're going to get these osteophytes which are these bony out pouches you're going to get this subchondral cysts which is going to represent the cartilage that is going to be messed up as well as the sclerosis which is basically bone on bone remember that there are many wear and tear disorders for your u.s emily one is osteoarthritis the other one is aortic stenosis because aortic stenosis again wear and tear and you can get that dystrophic calcification as you age so what i say when you're talking about rheumatoid and osteoarthritis questions pay attention to the joints involved which we're talking about as well as the degree of morning stiffness rheumatoid arthritis has a lot of morning stiffness i.e greater than half hour for example and you want to understand the progression i.e rheumatoid arthritis the joint stiffness is worse in the morning whereas osteoarthritis the joint pain is worse at the end of the day so let's go through a compare and contrast of rheumatoid and osteoarthritis rheumatoid arthritis it's going to affect more younger patients you're going to have this autoimmune process that is going to give you high amount of inflammation and you are going to get a lot of morning stiffness because as that inflammation calms down at night in the morning you wake up and you're like god dang this is stiff stiff stiff and it takes greater than an hour half hour for that stiffness to kind of get a little bit better you're also going to get the small joints and the metacarpal phalangeal as well as pip joints those are going to be the two joints in rheumatoid arthritis remember that because this is autoimmune this is going to be a rheumatoid rheumatological disease you are going to have positive rheumatoid factor which we're going to go into as well as anti-ccp antibodies that are going to be positive the way i remember that is take your hand make a c another c oh it's stiff stiff diff rheumatoid arthritis ccp all right you're gonna use uh these dmard agents and this is covered in my pharmacology course so definitely check it out but one important thing to recognize is that we use methotrexate which inhibits dihydrofolate reductase osteoarthritis this is more of a biomechanical process it is a wear and tear so you're going to have different joints involved you're going to have the knees for example as well as the dip distal interphalangeal joints and the pips involved you may have some morning stiffness but it won't be too prolonged you're not going to have auto antibodies and you're going to have osteophytes which are going to be seen on your x-ray which is representation of bone on bone what i want you to recognize is that the treatment for osteoarthritis is primarily going to be related to nsaids but you got to understand the complications of nsaids as well remember the nsaids are going to downstream reduce the prostaglandins and thus you are going to get stress gastritis related to nsaid use you are going to get bleeding related to nsaid use you are going to get issues with kidney function related to nsaid use so if they put in your history oh patient has osteoarthritis watch out for the complications of nsaids which they can test you on so rheumatoid arthritis let's go ahead and illustrate the concept a little bit more a 44 year old woman comes in for swollen fingers in the past six months she says that she has some stiffness in the morning which takes over an hour to resolve what physical exam findings may you find on our upper extremity exam so just to recall remember that you are going to have swelling more of your pip and your mcp joints and that is characteristic of rheumatoid arthritis as well as systemic symptoms remember that rheumatoid arthritis is going to be associated with hla dr4 and the way that i remember it is that oh you're talking about joints one hand two hand one leg another leg up there are four things hladr4 related to rheumatoid arthritis so let's go through the pathophysiology i think it's really important for us to understand remember that the synovium which is going to essentially be the matrix that your joint is going to have surrounding it that actually is going to be lined by infiltrating lymphocytes and these infiltrating lymphocytes in rheumatoid arthritis wreak the havoc they cause you to have edema they cause you to have inflammation and subsequent fluid-like collections or panus formation as well as then that becomes granulation tissue and patoma tells us that oh man granulation tissue has three things granulation tissue type three collagen three things blood vessels fibroblasts and myofibroblasts and it is these myofibroblasts that are going to be responsible for the ulnar deviation that we see with rheumatoid arthritis very high yield for us to know these integrations so here is that ulnar deviation and you see that it is because you have the actual myofibroblast that contract and then you have the deviation of the hands so what i want you to recognize is that rheumatoid arthritis it's all about inflammation and we talked about lymphocytes but we also have to appreciate the neutrophils that are going to be recruited into the joint so here's your immunology time remember that with these lymphocytes you are going to get activation of your acute phase cytokines things like tnf alpha il1 il6 and subsequently what that's going to do is that's going to activate b cells downstream to make rheumatoid factor and i think this is the time to overlay the concept rheumatoid factor is an antibody to an antibody i.e it is igm auto antibody to the fc portion of igg and whenever you have this antibody antibody complex that ends up being an immune complex deposition especially in the joints and that activates complement specifically when you activate your pathways of complement you're going to get a activation of or an increase of c5a and c5a very high yield for us to know is going to recruit neutrophils so when you attract neutrophils due to complement activation you can get this pianist formation the granulation tissue is going to be there and that granulation tissue brings with the blood vessels which gives you those cytokines and that destroys the joint but i'm not done there yet because we got to know the other mediators for neutrophil recruitment and that is ltb4 c5a which got us into the mess il8 and bacterial products those chapters one through three of patoma are very very high yield and that's why in my test taking strategies rapid review course i go through it just like this in a question-based applied manner so that you are able to really excel on these questions for your usma exam and test day all right rheumatoid arthritis has systemic integrations and these presentations can actually be on your exam so let's go through the presentations the skin finding you're going to be thinking about those rheumatoid nodules if you biopsy those you're going to see necrotizing granulomas again inflammation related you can get hair loss because you are going to affect the actual skin glands themselves from a hematological standpoint these patients have anemia of chronic disease remember that is characterized by a high eye findings with rheumatoid arthritis episcleritis and scleritis you see that the sclera is the white part of the eye and the blood vessels underneath are going to be very inflamed because you are going to have inflammation you are actually going to have atlantoaxial instability especially if you have chronic rheumatoid arthritis now that is where you have instability of your upper cervical vertebrae and if you have ins if you have instability and you have the patient in your exam question in which they're about to intubate and uh extend the neck you can sever the spinal cord now where else do you see at lamtoaxial instability not only in rheumatoid arthritis but you're gonna see it in down syndrome as well because they have some laxity of that ligament the cardiac manifestations of rheumatoid arthritis is going to be again inflammation related so you're thinking about pericarditis and lung wise you can actually get interstitial fibrosis because of the activation of cytokines such as tgf beta so when we think about rheumatoid arthritis we have to integrate these vignettes we want to think like the test maker that's my goal all of my programs outline study schedule et cetera focus on making sure you look at material as how it's going to be tested that's the new shift so say for example you have rheumatoid arthritis and bam blunted costophrenic ankles you're thinking about a pleural effusion because you have some pleuritis associated with the inflammation rheumatoid arthritis plus intubation but plus spinal cord paralysis bam they're going for atlantoaxial instability rheumatoid arthritis patient plus chest pain worse with lying down bam pericarditis rheumatoid arthritis plus apple green birefringence ah here you're going to be thinking of amyloid and remember that saa is that acute phase reacted in inflammation and that deposits as a amyloid rheumatoid arthritis plus this growth on the back of the knee ah remember that panas formation that can lead to a baker's cyst rheumatoid arthritis plus an anemia you're going to be thinking of anemia of chronic disease and remember that when you think of anemia of chronic disease remember hep cytin is upregulated that inhibits iron utilization and that's why you have a high ferritin and then with rheumatoid arthritis and anemia you add splenomegaly and another cell line ie neutropenia with that you're going to be thinking of felting syndrome ladies and gentlemen these lectures are kind of like guided anki decks however they put the concepts together so i would encourage you to utilize my other reviews my other resources because when you think like the test maker you're going to build confidence and confidence allows for you to apply yourself better we're almost done let's go ahead and keep going with this question a 48 year old female presents for joint pain she is noted to have an elevated esr and crp i'm smelling inflammation x-ray of her joints are notable for joint space narrowing in the mcp and auto antibody is detected which of the following substances is most likely the target of this auto antibody a fc portion of igg b sheep erythrocytes c sphingomyelin d double stranded dna or e u1 rnp answer is going to be rheumatoid factor which is an antibody to an antibody and a is the correct answer all right we have two more concepts left we're going to be talking about the seronegative spondyloarthropathies we're going to be talking about lupus and then we have the conclusion with our antibody rapid fire so stay tuned stay engaged go ahead put in the chat are you guys learning are you having fun yes or no keeping me pumped awesome excellent i really appreciate you guys moshe katarina giorgis dipendra excellent job kind of staying engaged uh you guys really pumped me up all right excellent so the next concept is going to be seronegative spondyloarthropathies so let's go ahead and talk about the big picture overview remember that they're called seronegative because you have an absence of rheumatoid factor and that's high yield for us to know they have this association with hla b27 and the way that i remember it is i remember it as pear psoriatic arthritis ankylosing spondylitis ibd ibd-associated arthritis and reactive arthritis p-a-i-r so we're gonna attack each of these first question a 28-year-old male presents with dull low back pain he is noted to have back pain in the morning there is no trauma physical exam is significant for decreased extension of the spine while standing his pft's pulmonary function tests are abnormal which are the following features is most likely present in this patient's workup hla class ii positivity m-protein molecular mimicry igm to igg vertebral fusion on chest x-ray or e perivertebral abscesses with lytic lesions and so if you're thinking about ankylosing spondylitis here you're absolutely correct and the answer is that bamboo spine the vertebral fusion on chest x-ray remember hla b27 that's going to be class 1 hla very high yield for us to know all right so we're going to talk about psoriatic arthritis patient presents with a scaly rash that bleeds when disrupted this is important he has joint pain what is the classic radiographic finding and you can see this classic radiographic finding and pardon my drawing but i'm going to draw it in that is that patient excuse me pencil in cup deformity related to psoriatic arthritis so you know here's the cup and you're going to have the pencil within the cup and that indicates that joint space narrowing there as well so pencil and cup deformity and remember that the ospit sign is going to be ah you have a really scaly lesion and you take off those scales you have pinpoint bleeding underneath that's the ospit sign all right very good so what's important for us to recognize with psoriasis the rash itself which can predispose you to the arthritis is that the rash itself has a lot of acanthosis and perikeratosis ecamtosis is the thickening of the epidermis whereas perikeratosis is that thickening that is going to still have the keratinocytes having nuclei nuclei within the stratum corneum and remember that for keratinized tissue usually you don't have that so perikeratosis means oh wow there's a lot of nucleated keratinocytes ankylosing spondylitis we need to talk about the vignette one more time 22 year old man comes in lower back pain he has burning in his eyes as you can notice that these patients have not only back pain but they are going to have the uveitis as well x-ray of the hip demonstrates abnormalities of the central skeleton what is the likely pulmonary complication associated with this condition so ankylosing spondylitis because it is going to cause you to have issues with your chest wall you're going to be thinking about a restrictive lung pattern and that's that pulmonary association yes you can get fibrosis but i want you to understand that the involvement of the back of the vertebra as well as the thoracic cavity can cause you to have an impairment of filling your lungs and that's restrictive lung disease the ophthalmological association is anterior uveitis and the x-ray finding is the bamboo spine as you can see the vertebrae are kind of clumped together like a bamboo tree and anterior uveitis is that inflammation especially in the anterior chamber of the eye reactive arthritis is going to be next recognize this triad here a young man works in a daycare had bloody diarrhea one week prior and now presents with red eye feels pain during urination and says his ankle hurts especially after he runs after the toddlers i was having way too much fun writing these right what is the likely diagnosis here and you're going to be thinking of that triad which is can't see can't pee can't climb a tree but you notice that i have placed this in a very unique way also you got to understand the trigger and that's high yield for many questions put down that trigger or kind of integrate that trigger in your mind the classic presentation is this asymmetric joint arthritis and remember that there are many organisms that are related to reactive arthritis but the two that i want to highlight are shigella which is a gram-negative rod that causes blood diarrhea as well as chlamydia and that is a gram-negative cocoa bacillus the skin finding with reactive arthritis is something known as keratoderma blemoragica and this is this unique rash that actually affects the palms and souls very very interesting uh association with reactive arthritis so speaking of palms and souls we talk about keratoderma blomeragicum related to reactive arthritis but here are all of the rashes which involve the palms and souls and this is something that in your physical exam questions for dermatology if you see it involves the palms and souls you got to think about this differential ready men drive kawasaki cars men drive meningococcus remember this is going to be related to a pustular rash kawasaki which is going to be any child on your u.s emily that has fever for greater than five days you want to think about kawasaki disease coxsackie a virus remember it causes hand foot and mouth disease all others which that's going to relate to toxic shock syndrome the janeway lesions the osler nodes that you're going to be uh seeing in uh your infective endocarditis as well as rider syndrome r is going to be rocky mounted spotted fever watch for headaches hyponatremia recent travel used doxycycline and s secondary syphilis it's a copper colored rash men drive kawasaki cars i hope that mnemonic helps you so here's the summary of the seronegative spondyloarthropathies psoriatic arthritis which gives you the pencil and cup deformity ankylosing spondylitis watch for the bamboo spine giving you restrictive lung disease and reactive arthritis can't see can't pee can't climb a tree we're going to go ahead and finish off this content review with lupus related to lupus what we have to understand are the multi-system manifestations of lupus let's go ahead and go through this question a 30 year old female presences presents with shortness of breath she is diagnosed with the unilateral pleural effusion via chest x-ray her further laboratory studies are notable for anemia with high ferritin her three-month follow-up shows increased creatinine and a ua that's positive for blood and protein so you notice that she has anemia she has issues with kidney failure which of the following mechanisms most explains as you can see a very specific stem renal dysfunction autoimmune attack of podocytes light chain deposition deposition of immune complexes or d sub-epithelial humps secondary to chronic streptococcal infections and so many of you are recognizing this is lupus nephritis and you're thinking about this deposition of immune complexes very high yield for us to know so the pathophysiology of lupus is very complicated but i did want to break it down for you number one remember that lupus has that genetic predisposition and then the environmental trigger with it very high yield for us to know what's also important for us to recognize is that this gives you a polyclonal activation of b cells and those b cells secrete antibodies and those antibodies actually target dna that's why anti-double-stranded dna is positive in lupus you also want to understand that lupus is a combined type 2 hypersensitivity and a type 3 hypersensitivity so for example in your labs you're going to have leukopenia anemia thrombocytopenia that is associated with lupus but you can also have type 3 hypersensitivities which is associated with deposition of immune complexes like we saw in our question related to the nephritis so it just kind of depends on where or what manifestation you are talking about another type 2 hypersensitivity reaction is going to be the anti-phospholipid syndrome related to lupus which we'll get to so what i like to say for lupus questions is watch for mucositis because that's the inflammation of various surfaces heart lung etc and cell lines being affected so leukopenia thrombocytopenia and anemia of chronic disease so lupus patients are going to have a symmetric non-erosive arthritis they're going to have that characteristic malar rash and the uv light is going to worsen that mylar rash they can have cardiovascular manifestations such as fibrinous pericarditis which is related to inflammation as well as these sterile vegetations on both sides of the valve and that's called libman sex endocarditis so remember libman sacs lupus very high yield kidney involvement is very very important you're going to be thinking about diffuse proliferative glomerulonephritis which is the nephritic syndrome the nephrotic syndrome can you think of what the presentation is there it's membranous glomerulonephropathy tune into my renal review i think of it as oh you're a member of the lupus community so membranous glomerular nephropathy you're going to be thinking about the pulmonary manifestations especially related to serositis ah there's a plural effusion that blunted costophrenic angle and you're going to be thinking about cns lupus this a very severe in which these patients have psychosis as well as seizures now lupus you've got to understand this vignette 22 year old woman with lupus has a follow-up exam she is kipnic and tachycardic and imaging is notable for a dvt in her leg two years ago two years ago she delivered a female stillborn at 23 weeks her platelet count is normal pt is normal she has an increased ptt but why the hell does she have clots what is the mechanism ah here we're gonna be thinking of anti-phospholipid antibody syndrome which is essentially antibodies directed to phospholipids you get membrane damage you get activation of the coagulation cascade why because you hit one of virchow's triad and that is basically one hyperquagable state as well as endothelial injury very high yield for you to know now remember that antiphospholipid syndrome can cause you to have false positive syphilis tests and what's unique and it's paradoxical that your ptt has increased however you are still hyper-coagulable so watch for recurrent spontaneous abortions as one of your presentations so lupus when you're thinking about the diagnosis what's sensitive but not specific is your ana ana is very very sensitive but it's not really helpful to diagnose any of these rheumatological diseases specific markers are going to be anti-double-stranded dna as well as anti-smith antibodies remember the anti-smith is related to your snr np's anti-double-stranded dna antibodies the actual serology can uh uh bode poor prognosis and is associated with flares and you're going to have some low complement because of the immune complex deposition now there is a lupus-like syndrome which i want you to really recognize for your usmle and that usually involves a drug trigger so a patient is on a medication for wolf parkinson white the diagnosis here is drug induced lupus and drug industry has a different antibody that's the anti-histone antibody so let's go through drug-induced lupus real quick so typically your us emily presentation is going to be ah a patient with fever and joint pain with a malar rash i.e lupus-like symptoms after being treated for different things such as an arrhythmia hypertension inflammatory disease or tuberculosis and what they're going for with that drug trigger is the fact that these patients can have anti-histone antibody positivity related to the drug trigger and develop a lupus-like syndrome that you need to recognize so what are the high-yield medications associated to drug or associated with drug-induced lupus you're going to be thinking about procainamide hydralazine isoniazid as well as tnf-alpha inhibitors so procainamide is a sodium channel blocker antiarrhythmic hydralazine is going to be an anti-blood pressure medication because it vasodilates inh you want to think about that related to tb mycolic acid inhibition and you want to prevent the peripheral neuropathy by giving b6 and then tnf alpha inhibitors you are going to be seen commonly employed in not only rheumatological diseases but also gi diseases like ibd just to wrap up lupus i want to really go through the systemic manifestations because just like in the icu i like to break these pathologies down in a systems-based manner so we talked about the fact that patients with lupus can have fever as well as cognitive issues we talked about the pericarditis and the libman sex endocarditis remember endocarditis usually presents as fever plus a murmur on your usmle the respiratory manifestations related to pleural effusions renal manifestations we talked about diffuse proliferative glomerulonephritis remember the spike and dome appearance you note with membranous glomerulonephropathy and the low complement hematologically you get anemia of chronic disease you get thrombocytopenia that could actually make you hypercoagulable as well as leukopenia as antibodies are attacking your various components of your cbc msk we talked about atlantoaxial instability related to sorry rheumatoid arthritis but in lupus you're going to get more of this migratory arthritis and skin manifestation being the butterfly rash and photosensitivity remember there's a discoid subtype for you to know for your exam and then remember the antibodies ana is sensitive but these are going to be your specific ones ladies and gentlemen that brings us to the last portion of this review and that is going through the antibody parade we're going to be going through a lot of pathologies here's a rapid fire for you and i have this same rapid fire in my rapid review course as well as other rapid fires for you so let's go ahead and put on our seat belts let's power through these last five minutes of this session and i can't wait to answer your questions as well so one test-taking strategy for us to recognize is that rheumatological diseases have multi-system involvement they affect the gi tract the muscles causing myositis we talked about pulmonary manifestations heme manifestations so watch for multi-system involvement and then the antibodies given in your labs kind of funnels down the diagnosis so let's focus on these antibodies hla b27 psoriatic ankylosing ibd rider syndrome or reactive arthritis c anka we talked about that being related to antiproteinase iii and it is related to gpa pinka is going to be mpa and church strauss which is known as eosinophilic gpa you also understand that ulcerative ulcerative colitis as well as primary sclerosing cholangitis is going to be p enco positive anti-acetylcholine receptor you're going to be thinking about myosin or gravis anti-basement membrane antibody you're going to be thinking about good pasture syndrome hemoptysis and hematuria anti-beta-2 glycoprotein that's specifically going to be positive in anti-phospholipid syndrome remember we talked about that with lupus anti-ccp which one was that guys go ahead and put that in the chat anti-ccp yeah all right rheumatoid arthritis you got it anti-centromere antibody that's going to be c for centromere c for crest syndrome and so these patients especially have telangiectasias which are the spiral-shaped vascular lesions as well as the esophageal dysmotility which presents as dysphagia anti-desmasome we talked about that with pemphigus vulgaris remember anti-hemidesmosome that was going to be your bolus pemphigoid anti-double-stranded dna and anti-smith that's lupus anti-endomesial antibody that's going to be celiac sprue watch for the blunted v li as well as the dermatitis herpetiformis anti-histone antibody drug-induced lupus remember that they test you on not only the drugs but the associated conditions we use the drug for anti-jo1 that's going to be antibodies to trna synthetase and that is related to polymyositis and dermatomyositis watch for your exam questions that are going to have high cpk which is a marker for muscle damage anti-mitochondrial antibodies that's primary biliary cirrhosis remember cienka's psc that's a biliary tract pathology anti-mitochondrial antibody that's pbc anti-topo isomerase that's going to be systemic scleroderma now that presents on your usmle as oh man i have malignant hypertension why because you have sclerosis of for example your kidney and the kidney vasculature and oh my god that shoots up your blood pressure so anti-topoisomerase is also anti-scl70 last slide here we're talking about anti-smooth muscle or anti-lkm you're going to be thinking of autoimmune hepatitis anti-roe or anti-la those are also known as anti-ssa or anti-ssb now these can be weakly positive in lupus but what's important is that they are seen in sjogren's syndrome but also important is that ssa can cross the placenta and you can have complete heart block in a neonate because of the ssa antibodies that's a high-yield question anti-thyroglobulin that's hashimoto's and anti-voltage-gated calcium channel that's going to be lambart eaton syndrome let's go ahead and wrap up our last push is going to be answering this exam question 31 year old presents with general malaise myalgias and low grade fever she is noted to have painful extremities especially in the winter time as she states her fingers turn blue she has that rain odds phenomenon she was recently hospitalized for a myositis flare on physical exam she has a malar rash on the nose the patient is also noted to have joint tenderness in the mcp and the dip joints lab testing is positive for anti-nuclear antibodies so you're thinking of an autoimmune disease which of the following antibodies may also be present given this clinical presentation so why i wanted to end with this is because this is a unique pathology known as mixed connective tissue disease it has a mix of all of the syndromes which we talked about things like lupus things like for example the myositis flare like a dermatomyositis polymyositis joint involvement and so mixed connective tissue disease has a little bit of everything and it is related to anti-u1 rnp antibody ladies and gentlemen thank you for attending today but i want you to stick around for the test-taking conclusion and i want to highlight some of the resources which will also help you for your usml exam if you enjoyed this review remember that you need to take home that rheumatology questions have multi-system involvement and you want to integrate those antibodies in your exam vignettes if you love the active recall and integration i encourage you to check out my test taking strategy and rapid review course it basically gives you a one-on-one private tutoring experience right in the comfort of your study space we talk about test taking strategies which is very unique that helps you with your new world blocks we go through chapters one through three of pathoma go through a rapid review of all of the organ systems i even cover some pharmacology and some gross anatomy so i would 110 advise you to check that out and use it as part of your preparation i also just released what you need to know for pharmacology and this course basically covers the 20 actual uh uh content spec that you will see on your usmle remember that pharmacology is twenty percent of your us mla and they're easy points so this course covers the highest yield drugs that you need to know and it basically integrates pathophysiology and sketchy micro together i want to teach pathology more or excuse me pharmacology more from a pathophysiology standpoint and then finally i do have a unique option and that is the course bundle and the course bundle which you will see on my website higru.com the course bundle basically has all of my resources there for you and it comes with a one-on-one session with me because hey you're taking a chance on me i want to make sure i invest my time and energy in you so it comes with the study plan it comes with the rapid review the pharmacology course everything in one so that you can excel and that's why i like to sit down with you go through some test taking strategy it comes free with the course bundle so definitely check that out and we can get that scheduled i just want to end this session by thanking you for showing up today and being so active and engaged your energy drives me to be better and please make sure you connect with me tag me in your stories blow high guru out of the water because as you know this is very valuable content and i do my best to make sure that i'm energetic focus on high yield and i'm really employing active recall techniques before you log off today go ahead in the chat type in one thing you learned today go ahead and type in the chat one thing you learned and that class dismissed one thing that you learned i'd love for you to share that with me and thank you guys so much for joining all right integrating test taking strategy i love it what about some content that you guys learned awesome no thank you so much donja for uh utilizing the rapid review pharmacology course compare and contrast i love mixed connective tissue disease oh this is a good one heart block in baby of mother with sjogren's syndrome that's that's pretty that's pretty epic i i absolutely love that excellent excellent