Dermatomyositis -- American Family Physician

Cutaneous manifestations of dermatomyositis are generally grouped as pathognomonic, characteristic, compatible, less common and rare (Table 4). The primary lesion appears as a violaceous, macular erythema with a symmetric distribution. This may progress and become poikilodermatous (atrophic with telangiectasia and pigmentary changes) and indurated (as a result of mucin deposition). Pathognomonic manifestations include Gottron’s papules and Gottron’s sign (Figure 1). Gottron’s papules, violaceous papules overlying the dorsal interphalangeal or metacarpophalangeal areas, elbow or knee joints, occur in approximately 70 percent of patients with dermatomyositis. Gottron’s sign is erythematous or violaceous, often atrophic, macules or plaques in the same symmetric distribution D ermatomyositis is an idiopathic disorder that includes an inflammatory myopathy and characteristic skin manifestations; polymyositis includes the inflammatory myopathy without the cutaneous findings. The etiology of dermatomyositis remains unknown; some studies have reported an association with histocompatability antigens, environmental agents (e.g., virus, drugs) and autoimmunity. The average age at diagnosis is 40, and almost twice as many women are affected as men. The average age of onset in juvenile dermatomyositis is between five and 14 years. This subgroup of patients has a better prognosis than adult patients. Modern Dermatomyositis is an idiopathic inflammatory myopathy with characteristic skin manifestations. Although the disorder is rare, with a prevalence of one to 10 cases per million in adults and one to 3.2 cases per million in children, early recognition and treatment are important ways to decrease the morbidity of systemic complications. An association with other connective tissue disorders (overlap syndrome) and malignancy make this diagnosis particularly important to primary care physicians. Patient management includes careful evaluation for underlying malignancy and liberal use of physical therapy, antihistamines, sunscreen and oral corticosteroids. Poor prognostic indicators include poorly responsive disease, delay in diagnosis and the presence of malignancy. The therapeutic goal is to maintain function and prevent or minimize sequelae. (Am Fam Physician 2001;64:1565-72.) Dermatomyositis