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What is Which one of the following clinical findings excludes the diagnosis of polymyositis? and explain in detail?
PM don't have any of the following:rashes ,involvement of extraocular and facial muscles ,family history of neuromuscular disease,history of exposure to myotonic drugs or toxins ,endocrinopathy ,neurogenic disease,muscular dystrophy ,biochemical muscle disorder. Ocular muscles are never involved in generalized polymyositis. However, isolated orbital myositis, an inflammatory disorder involving the extraocular muscles, is well described. Facial and bulbar muscle weakness is extremely rare in individuals with polymyositis Ref Harrison20th edition pg 2366