Lupus vulgaris: a case that escaped diagnosis for twenty-eight years.

Lupus vulgaris is uncommon in the United States and occasionally goes unrecognized for years before the diagnosis is made. A 65-year-old Mexican-American man with disseminated tuberculosis was discovered to have a large annular lesion of lupus vulgaris on his buttocks and thighs. The lesion had been present and slowly enlarging for twenty-eight years. The clinical and histologic features of primary inoculation tuberculosis and reinfection tuberculosis of the skin are reviewed.