Dermatomyositis The cutaneous manifestations of dermatomyositis (Chap. 383) are often distinctive but at times may resemble those of systemic lupus erythematosus (SLE) (Chap. 313), scleroderma (Chap. 316), or other overlapping connective tissue diseases (Chap. 316). The extent and severity of cutaneous disease may or may not correlate with the extent and severity of the myositis. The cutaneous manifestations of dermatomyositis are similar whether the disease appears in children or the elderly, except that calcification of subcutaneous tissue is a common late sequela in childhood dermatomyositis. The cutaneous signs of dermatomyositis may precede or follow the development of myositis by weeks. | Chapter 055. Immunologically Mediated Skin Diseases Part 7 Dermatomyositis The cutaneous manifestations of dermatomyositis Chap. 383 are often distinctive but at times may resemble those of systemic lupus erythematosus SLE Chap. 313 scleroderma Chap. 316 or other overlapping connective tissue diseases Chap. 316 . The extent and severity of cutaneous disease may or may not correlate with the extent and severity of the myositis. The cutaneous manifestations of dermatomyositis are similar whether the disease appears in children or the elderly except that calcification of subcutaneous tissue is a common late sequela in childhood dermatomyositis. The cutaneous signs of dermatomyositis may precede or follow the development of myositis by weeks to years. Cases lacking muscle involvement . dermatomyositis sine myositis have also been reported. The most common manifestation is a purple-red discoloration of the upper eyelids sometimes associated with scaling heliotrope erythema Fig. 55-3 and periorbital edema. Erythema on the cheeks and nose in a butterfly distribution may resemble the malar eruption of SLE. Erythematous or violaceous scaling patches are common on the upper anterior chest posterior neck scalp and the extensor surfaces of the arms legs and hands. Erythema and scaling may be particularly prominent over the elbows knees and the dorsal interphalangeal joints. Approximately one-third of patients have violaceous flat-topped papules over the dorsal interphalangeal joints that are pathognomonic of dermatomyositis Gottron s sign or Gottron s papules Fig. 55-4 . These lesions can be contrasted with the erythema and scaling on the dorsum of the fingers in some patients with SLE which spares the skin over the interphalangeal joints. Periungual telangiectasia may be prominent. Lacy or reticulated erythema may be associated with fine scaling on the extensor surfaces of the thighs and upper arms. Other patients particularly those with long-standing disease develop areas
