Dermatomyositis and dermatitis herpetiformis.

Primary hypothyroidism, dermatomyositis, dermatitis herpetiformis (DH), and Sjögren's syndrome developed sequentially, over a 20-year period, in a 67-year-old woman. The principal manifestations of her illness were periodic and simultaneous exacerbations of dermatomyositis and DH. Her histocompatability antigens were A1,B8, a haplotype associated with autoimmune diseases. We suggest that this unusual disease complex has a genetic basis.