During July 1983 to December 1984, we observed that 62 (46%) of 134 Haitian patients with acquired immunodeficiency syndrome had intensely pruritic eruptions for which neither specific causative nor categoric diagnoses could be established. These lesions were a presenting manifestation of acquired immunodeficiency syndrome in 79% of the patients and appeared a mean of 8 months before the diagnosis of either Kaposi's sarcoma or opportunistic infection. Lesions included erythematous round macules, papules, or nodules that first appeared on the extensor surface of the arms, but subsequently involved the legs, trunk, and face. Histologically, the lesions were characterized by varying degrees of mixed (predominantly eosinophilic) perivascular and perifollicular inflammatory cell infiltrates of the dermis. The lesions did not respond to any therapeutic regimens used and usually persisted throughout the acquired immunodeficiency syndrome illness. Demographic and laboratory data did not distinguish these patients from those without pruritic skin lesions.