hi everyone this is an overview lesson on allergic rhinitis so in this test we're going to talk about the risk factors for getting allergic rhinitis we'll also discuss some of the pathophysiology behind the condition and we're also going to talk about these signs and symptoms how it's diagnosed and how it's treated so allergic rhinitis is also known as hay fever and it is a condition involving inflammation of the nasal mucosa due to allergens so your nasal mucosa inside your nasal cavity becomes inflamed when they get exposed to certain allergens now there are actually two types of allergic rhinitis one type is known as seasonal or intermittent and as its name implies it occurs at certain seasons or during certain periods of the year so this usually occurs when certain plants pollinate at certain times of the year and these pollens usually include true grasses certain trees like spruce and pine and certain weeds and then there's the second type of allergic rhinitis known as perennial or chronic and as its name implies it occurs throughout the year and this is when exposures are persistent as well these might include mold spores dust mites and animal dander so chronic exposures to certain allergens now what is epidemiology of this condition it is a relatively common condition it is estimated to affect 15 to 30 percent of individuals and the severity of this condition peaks around the second to fourth decade of life and broken down approximately 20 have seasonal 40 have perennial and 40 have both now let's talk about some associated conditions and risk factors for getting allergic rhinitis so one major association with allergic rhinitis is something called the atopic triad so the atopic triad consists of allergic rhinitis atopic dermatitis and asthma and as you can see they all start with the letter a and they are all conditions involving increased immunoglobulin e or ige and this will become important when we talk about some of the pathophysiology behind this condition so again allergic rhinitis atopic dermatitis and asthma they all are associated with one another if you have one you're more likely to have one or both of the other ones and then additionally you're also more at risk for having certain other allergic reactions so one example of this might be food induced urticaria urticaria are hives so hives might develop after eating certain foods and this is more likely to happen in patients who have one or multiple of these atopic triad conditions so what are some of the risk factors for getting this condition number one is family history and there does appear to be some genes on chromosomes three and four that seem to be related to allergic rhinitis so certain alleles of those genes are more likely to be present in patients who have issues with allergic rhinitis being of the male gender is also another risk factor for having allergic rhinitis higher socioeconomic status is another risk factor in exposure to cigarette smoke in the first year of life these are all risk factors for getting allergic rhinitis now there are actually some protective factors that may reduce the risk for an individual getting allergic rhinitis these include the following breastfeeding owning a pet at an early age and exposure to farm animals in first years of life these are possible protective factors for not only allergic rhinitis but some of these other conditions as well atopic dermatitis and asthma so being exposed to farm animals in the first year of life in particular very important seems to have a protective effect and some possible protection from these conditions if you own a pet at an early age so your exposures in early life seem to be very important in this condition and some of these other atopic triad conditions as well now let's talk about the pathophysiology behind allergic rhinitis so there are two phases of allergic rhinitis the first phase is known as the early phase this is when a patient is exposed to a particular allergen and the allergen triggers an increase in immunoglobulin e levels or ige levels and we mentioned before that atopic triad conditions including allergic rhinitis are associated with higher ige levels so an allergen will trigger a release of immunoglobulin e and that immunoglobulin e will bind and cross-link to mast cells and these are very important cells to remember ige will bind to these cells and cause them to degranulate and when i say d granulate i mean that they have pre-formed vesicles of certain cytokines so when ige binds to mast cells it causes the release of those pre-formed cytokines and some of them include the following inflammatory mediators like histamine and leukotrienes and the histamine leukotrienes in particular histamine can lead to local inflammation histamine itself can act on the trigeminal nerve to cause sneezing and histamine along with some other inflammatory meat eaters can act on the mucous glands to increase the production of mucus and the secretion of mucus so this is why we can see runny nose in patients with allergic rhinitis and all of this usually takes place within five to 15 minutes of exposure now there's a late phase of allergic rhinitis as well so what happens in the late phase is that mast cells release other cytokines and these include the interleukins in particular interleukin-4 in interleukin-13 are released from mast cells during this phase and what these interleukins do is that they lead to cell migration and infiltration into the nasal mucosa so certain cells that are brought into the nasal mucosa include eosinophils and what that does is that this causes nasal edema and congestion so the nasal mucosa becomes swollen and congested and all of this takes place within four to six hours of exposure so you can see that there is an early phase that occurs more rapidly and then there's a late phase that occurs hours after exposure and both of these will contribute to the symptoms of allergic rhinitis that we're going to talk about in the next upcoming slides now let's talk about the clinical features of this condition rhinorrhea is going to be a very common symptom of allergic rhinitis so rhinorrhea is essentially a runny nose and we talked about this before histamine and other cytokines will act on those mucous glands to increase the production of mucus and secretion of mucus this is why we're going to see a runny nose in allergic rhinitis and what is going to be noted here is that the runny nose or the mucus that is running out of the nose is clear so it's a clear discharge there's also going to be sneezing in allergic rhinitis so you can imagine that if there's a lot of mucus in your nasal cavity that's going to cause some irritation to sneeze but histamine itself can also act on the trigeminal nerve to induce sneezing as well so this is why we're going to see sneezing in allergic rhinitis nasal pruritus is also going to be noted in this condition nasal pruritus is when the nose feels itchy so it's an itchy nose we can also see allergic conjunctivitis so allergic conjunctivitis conjunctivitis itis meaning inflammation and conjunctive referring to the conjunctiva of the eyes so allergic conjunctivitis is inflammation of the conjunctiva of the eyes and we can see in this image here they become inflamed and they can become watery so eyes can become very watery and red in appearance your eyes can also become very itchy so pre-ridic eyes and because of all of that congestion and mucous discharge in the nasal cavity we can see post nasal drip post nasal drip is when that mucus runs down the back of your throat down the fairings and this is going to cause some other issues as well and we can see some patients trying to clear their throat so they'll feel like there's something in the back of their throat and they're trying to clear their throat because of the post nasal drip and the sensation that there might be something irritating their throat they may have a non-productive cough so non-productive means that they're not coughing up any mucus they're just coughing because of the irritation from the post nasal drip we mentioned this before nasal congestion is also going to be a noted clinical feature in allergic rhinitis as well so a stuffy nose and with these three post nasal drip non-productive cough and nasal congestion these are more likely going to be seen in chronic or perennial type so essentially the chronic perennial type's not going to have these other more acute early phase signs and symptoms like rhinorrhea and sneezing they're going to have some of the consequences of having this for a longer period of time so having a congested nasal cavity with mucus running down the back of their throat is going to be postnasal drip and because of that they're going to have non-productive cough and they're going to have nasal congestion so these are going to be more present in the chronic perennial type of allergic rhinitis some other findings include the following allergic salute this is when a patient is rubbing their nose upward in this fashion this can lead to a crease on their nose that can be permanent or long-lasting so they may have a crease in their nose from doing this patients can also have eustachian tube dysfunction so in this image here these are the eustachian tubes and the eustachian tubes run down and connect to the nasal cavity so if there's any congestion and mucus production and inflammation in the nasal cavity it can lead to some inflammatory changes and some fluid in the eustachian tube and this can lead to station tube dysfunction eustace and tube dysfunction is going to lead to particular symptoms and most patients will describe popping or rice crispy type crackling sounds in their ears chronic sinusitis can also occur so inflammation of the sinuses especially if this is a chronic type of allergic rhinitis and allergic shiners can also occur in allergic rhinitis this is where there are these dark circles under the eyes this is due to vasocongestion under the eyes and some other findings we can see with allergic rhinitis have to do with the atopic triad we talked about before these patients may have asthma and atopic dermatitis so asthma they may have shortness breath and wheezing and in atopic dermatitis they may have areas on their skin that are red and itchy so if you want more information on these conditions please check my full lessons on these topics so how do clinicians diagnose and treat allergic rhinitis oftentimes the diagnosis of allergic rhinitis is a clinical diagnosis it's done by history and physical examination if a patient has described similar symptoms like runny nose and sneezing at certain times of the year or in certain situations or if they've had these symptoms for longer periods of time with no other symptoms this can be highly suspect for allergic rhinitis some more specific ways to diagnose this condition can be through serology testing for allergen specific ige so looking for specific immunoglobulin e that have been triggered by specific allergens that may be one way of looking at it so if a patient has an allergy to pollen from true grasses they can look for ige that is specifically against pollen from true grasses so that may be a way to diagnose this condition as well an allergy skin test is also another way to do this so there are small pin pricks on the skin with certain allergens and they see how much the patient reacts to those allergens that is a way of diagnosing this as well the contraindications to the allergy skin tests are the following though pregnancy uncontrolled asthma and cardiovascular disease are conditions where you would not want to do an allergy skin test and then it's also important to cease or stop tricyclic antidepressants anti-ige monoclonal antibodies and h2 receptor antagonists so you want to stop those type of medications before doing an allergy skin test because they can interfere with the results of the test so very important to stop those types of medications you can imagine that if you're taking anti-ige monoclonal antibodies you're not going to see this ige immediate response because you're taking an anti-ige medication and then h2 receptor antagonists you're blocking the effects of histamine so you're not going to see as much of an effect if you're on these medications like h2 receptor antagonists once a clinician has diagnosed this condition how do they treat it oftentimes it's important to identify the trigger and avoid the trigger so that is going to be the first step some other ways of dealing with symptoms include saline rinses of the nose a nasal glucocorticoid so nasal glucocorticoid is a nasal spray that reduces the inflammation and congestion of the nasal cavity this is going to most likely be the first line of treatment and it can be something that helps support the diagnosis in the first place if there is improvement of symptoms this supports the diagnosis of allergic rhinitis and as we mentioned before this oftentimes is going to be a first line treatment and antihistamines can also be used to treat symptoms so these include diphenhydramine or benadryl and leukotriene receptor antagonists can be used as well in specific situations so again it's important to identify and avoid those triggers we talked about before sometimes that's not possible and we're going to be treating symptoms so saline rinses nasal glucocorticoid or antihistamines are very common treatments for this condition so if you want to learn more about signs and symptoms of allergic rhinitis or foods and beverages to avoid if you have allergic rhinitis please check out my full lessons on those topics and if you haven't already please like and subscribe for more lessons like this one thanks so much for watching and i hope to see you next time