[Music] [Applause] [Music] hi this is Tom from zerof finals.com in this video I'm going to be going through Myositis and you can find written notes on this topic at zerof finals.com myositis or in the Rheumatology section of the second edition of the zero to finals medicine book and you can find flashcards and questions to train your knowledge and help you remember the information longer at members. zerof finals.com so let's jump straight in polymyositis and dermatomyositis are autoimmune conditions that cause muscle inflammation which is called myositis both conditions present with proximal muscle weakness at the tops of the arms and the tops of the legs dermatomyositis also involves characteristic skin changes specifically goton papules affecting the backs of the hands and the heliotrope rash affecting the eyelids polymyositis and demat myositis can be caused by an underlying cancer which makes them Paran neoplastic syndromes a viral infection may be the trigger for example Cox saki virus or HIV certain HLA genes are risk factors for the conditions let's talk about the presentation the typical presenting symptom is a gradual onset symmetrical proximal muscle weakness which causes difficulties in standing from a chair climbing stairs or lifting items overhead there may be muscle pain or myalgia but this is not always the case polymyositis occurs without any skin changes potential skin changes in dermatomyositis include goton leion which are scaly aratus patches over the knuckles elbows and knees the heliotrope rash which is a purple rash on the face and eyelids periorbital edema which is swelling around the eyes and a photosensitive emitus rash or red rash over the back shoulders and neck next let's talk about creatine kise the critical test for myositis or muscle inflammation is a creatine chinise blood test creatine chinise is an enzyme found inside muscle cells inflammation inside muscle cells or myositis causes the release of creatine cyas creatin cyas is usually less than about 300 international units per liter with myositis the result can be in the multiples of thousands other causes of a raised creatine kisee include rapto myis acute kidney injury myocardial infarction or heart attack Statin use and strenuous exercise next talk about making the diagnosis a diagnosis will be made by a Rheumatology specialist and this is based on the clinical features elevated creatine kise blood test Auto antibodies electromyography or EMG magnetic resonance imaging or MRI scans and a muscle biopsy there are many myositis specific antibodies with varying associations the most common one to remember is anti- joe1 antibodies associated with polymyositis finally Let's Talk About Management a rheumatologist will guide management new cases need to be assessed for possible underlying cancer patients May benefit from Physiotherapy and occupational therapy to help with muscle strength and function corticosteroids for example prednisolone are the firstline treatment for both polymyositis and dermatomyositis other medical options where the response to steroids is inadequate include immunosuppressants for example methotraxate or aopen IV immunoglobulins and biologic therapy for example in Flix amab or a tanp research has consistently shown that testing yourself after learning a topic has a powerful effect on how long you retain that information this is known as the testing effect studying and then testing yourself results in longer lasting and stronger recall on that information when tested at a later date even when compared with additional study sessions if you're preparing for a medical exam and you're not regularly testing your knowledge and practicing your recall you're failing to maximize your potential the Zer to finals member site contains flashcards short answer questions multiple choice questions and extended matching questions that are purpose built to supplement the zero to finals content helping you build your internal datab Bas of knowledge and take advantage of the powerful testing effect if you like the zero to finals notes books videos and podcasts then you'll love the memb site