Rebecca L. Euwer

We report six patients with the classic cutaneous findings of dermatomyositis who did not develop clinical or laboratory evidence of muscle disease for at least 2 years after onset of their skin manifestations. Such patients represent 11% of our total experience with dermatomyositis patients during a 15 year period. All six patients had Gottron's paules, periungual erythema/telangiectasia, and violaceous discoloration of the face, neck, upper chest, and back at some time during the course of their disease. In addition, all complained of pruritus and photosensitivity. None of the patients had evidence of malignancy. Each of five patients treated with oral corticosteroids for their cutaneous disease had marked improvement and did not develop myositis. These cases further emphasize that the cutaneous manifestations of dermatomyositis are pathognomonic of this disease and challenge the commonly held notion that muscle disease always develops within 2 years of onset of skin disease.

Dermatologists have long recognized that patients occasionally exhibit the pathognomic skin changes of dermatomyositis without clinical evidence of myositis for much longer than is typical for the classic form of this disease. The term dermatomyositis siné myositis has been used to refer to this condition in the past, although there is virtually no written record of this entity in the English-language medical literature. During the past 5 years, the disease course in such patients has been formally described in several case reports and small retrospective series, often under the designation amyopathic dermatomyositis. In this review, we discuss clinical issues relating to this poorly understood illness, including the possibilities of the existence of subclinical myositis, risk of occult malignancy, and risk of systemic disease manifestations normally associated with the classic form of dermatomyositis, such as interstitial lung disease. In addition, we address other issues of recent interest pertaining to the cutaneous manifestations of the inflammatory myopathies, such as unusual types of skin lesions, exacerbation of disease activity by ultraviolet light exposure, relative risk of intradermal bovine collagen injections, and management of corticosteroid-resistant skin lesions.