Polymyositis and dermatomyositis (first of two parts).
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D003095:Collagen Diseases / Q000150:complications; D003882:Dermatomyositis / Q000145:classification / Q000150:complications / Q000175:diagnosis / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007249:Inflammation; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000473:pathology; D009220:Myositis / Q000145:classification / Q000150:complications / Q000175:diagnosis / Q000473:pathology; D009369:Neoplasms / Q000150:complications / Q000453:epidemiology; D012737:Sex Factors; D013577:Syndrome; D014652:Vascular Diseases / Q000150:complications