Dermatologic aspects of myositis

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 occlt 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.