Cutaneous tuberculosis in Hong Kong: a 10-year retrospective study.

BACKGROUND: Cutaneous tuberculosis was once a relatively common skin disease in Hong Kong. Tuberculosis verrucosa cutis was the commonest type. Because the last survey was carried out 25 years ago, it was thought necessary to find out the new incidence and pattern of this important disease in this locality.

METHODS: A 10-year (1983-1992) retrospective survey on the epidemiologic and clinicobacteriologic aspects of cutaneous tuberculosis had been done in the public sector of Hong Kong. The records of the confirmed cases were retrieved for statistical analysis.

RESULTS: A total of 176 cases are included in the final analysis. This represents 0.066% of all new skin cases seen during the 10-year period. Among these, 79.5% are erythema induratum, 6.3% lupus vulgaris, and 4.5% tuberculosis verrucosa cutis. They are further divided into true cutaneous tuberculosis (14.8%, n = 26) and the tuberculide (85.2%, n = 150). Among the patients with true tuberculosis, 42.3% had lupus vulgaris, 30.8% had tuberculosis verrucosa cutis, and 26.9% had scrofuloderma. Among the tuberculides, erythema induratum accounted for 93.3%.

CONCLUSIONS: Cutaneous tuberculosis is now uncommon in Hong Kong. Tuberculosis verrucosa cutis is no longer the commonest type in Hong Kong as described in some textbooks. Erythema induratum is now the most common among the total cases and lupus vulgaris is the most common among the true cutaneous forms of tuberculosis.