[Epidemiology of dermatomyositis and polymyositis: the status of the diseases in Japan].
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003882:Dermatomyositis / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D007564:Japan; D008297:Male; D008875:Middle Aged; D009220:Myositis / Q000453:epidemiology; D009790:Occupations; D012737:Sex Factors