Cutaneous tuberculosis: a clinical, histopathologic, and bacteriologic study.

BACKGROUND: In recent years cutaneous infections with Mycobacterium tuberculosis with an atypical clinical appearance have become more common because of the increasing number of immunocompromised patients.
OBJECTIVE: We report the clinical, histopathologic, and bacteriologic data of 11 patients with several forms of cutaneous tuberculosis seen during the past 14 years.
METHODS: Patients from whom M. tuberculosis was isolated from culture of skin biopsy specimens, sinus drainage, or material aspirated from cutaneous abscesses were included. In all but two patients a biopsy specimen was obtained for histopathologic study. All but one patient received combined antituberculous therapy.
RESULTS: The clinical diagnoses were scrofuloderma (four cases), cutaneous miliary tuberculosis (two), lupus vulgaris (two), tuberculous gumma (two), and one unclassified. All but three patients had evidence of either previous or simultaneous tuberculous foci other than in the skin. Histopathologic findings varied according to the type of cutaneous tuberculosis.
CONCLUSION: In some patients with cutaneous tuberculosis, lesions are atypical in appearance because of immunodeficiency. Culture for M. tuberculosis should be performed in all suspected cases, even in those in whom special stains for acid-fast bacilli are negative.