Cutaneous sarcoidosis in black South Africans

Background It has been observed that, in the USA, sarcoidosis is more common in African-Americans than in other races. It has also been noted that sarcoidosis in African-Americans is characterized by more severe extrapulmonary involvement and more exuberant skin lesions. There is little information on sarcoidosis in black Africans. Methods Fifty-four black South African patients with cutaneous lesions of sarcoidosis proven by biopsy were prospectively studied. Dermatologic and ophthalmologic examinations and chest X-rays were performed in all patients. Other investigations relevant in the diagnosis of extracutaneous sarcoidosis were also performed in a variable number of patients. Results In 40 patients (71%), systemic sarcoidosis was found with lung, eye, and acral bone involvement being most common. Great variations in the morphology of skin lesions were observed. In one-quarter of patients, atypical cutaneous lesions (hypopigmented, ichthyosiform, lymphedematous, mutilating, ulcerative, verrucous) were found. Lupus pernio, once thought to be confined to Northern Europe, was observed in five patients in the subtropical milieu of South African Transvaal. Sarcoidal dactylitis with nail changes was seen in eight patients. Fibrinoid necrosis was found in 12% of the biopsies. Conclusions Sarcoidosis in black South Africans is characterized by extensive cutaneous involvement. The lesions are morphologically extremely variable, frequently atypical, and often demonstrate fibrinoid necrosis on histology.