[Sarcoidosis of the skin]

Sarcoidosis is characterized by formation of epithelioid-cell tubercules, without caseation, of the affected organ systems. The mediastinum, peripheral lymph nodes and eyes, in addition to the skin, are most frequently affected. Between 10% and 30% of patients with systemic sarcoidosis in Japan have skin lesions. Skin sarcoidosis is morphologically classified into three basic groups, erythema nodosum, scar sarcoidosis and skin sarcoid. Skin sarcoid is characterized by specific cutaneous lesions of sarcoidosis, and may take nodular, plaque, angiolupoid, subcutaneous and some other forms. Clinical manifestations of the cutaneous lesions are usually asymptomatic and polymorphous. Skin biopsy is, however, often highly useful for confirming a diagnosis of sarcoidosis.