The papulonecrotic tuberculide.

Ninety-one cases of papulonecrotic tuberculide were seen by the Department of Dermatology during the past 17 years. A focus of tuberculosis was found in 38%. Associated clinical phenomena included tuberculous arteritis with gangrene and the development of lupus vulgaris from papulonecrotic tuberculides. It is suggested that these tuberculides begin as an Arthus reaction which is followed by a delayed hypersensitivity response. The latter will prevent local proliferation of Mycobacterium tuberculosis in most cases, but in rare cases local multiplication of the organisms may lead to the development of lupus vulgaris. All patients improved rapidly on antituberculous treatment.