Pellagra is a systemic disorder caused by severe niacin deficiency. While uncommon in Europe and North America, pellagra and pellagra-like erythema are frequently encountered in undernourished adults in poor African countries. The purpose of this three-year prospective study was to determine the prevalence of HIV infection in patients with pellagra. Between 1996 and 1998, all documented cases of pellagra and pellagra-like erythema diagnosed in the Dermatology Department and Internal Medicine Department of the Teaching Hospital in Lome, Togo were included. Patients underwent screening tests for HIV infection. During the study period, pellagra or pellagra-like erythema was diagnosed in a total of 108 patients (59 women and 49 men) with a mean age of 41 +/- 3.5 years (range, 18 to 68 years). Serology tests for HIV were positive in 6 of these patients (5.5 p. 100; mean age 35 years). In four asymptomatic patients with no opportunistic infection, detection of HIV was an incidental discovery. The other two patients had AIDS symptoms. The principal causes of pellagra were malnutrition (n = 30), alcoholism (n = 15), and combined malnutrition and alcoholism (n = 60). The findings of this study suggest that the incidence of HIV infection in patients with pellagra and pellagra-like erythema is low, i.e., not higher than in the general population. This study also confirms previous etiologic and epidemiological data concerning pellagra in poor countries, i.e., the preponderant role of nutritional deficiency.