Comparative efficacy of drug regimens in skin tuberculosis

Summary Three antituberculous drug regimens have been employed to study the therapeutic response in 90 patients with any one of the commonly encountered paucibacillary forms of skin tuberculosis, namely lupus vulgaris, tuberculosis verrucosa cutis and scrofuloderma. The first two regimens contained rifampicin, isoniazid and either pyrazinamide or thiacetazone, and the third regimen had rifampicin and isoniazid only. The disease was clinically defined as localized when confined to one area and widespread when the lesions were disseminated. The observations revealed that the response of lupus vulgaris and tuberculosis verrucosa cutis was alike in all the three regimens, with the localized lesions subsiding completely after 4 months of therapy and the more extensive forms taking 5 months. Patients with scrofuloderma responded similarly to both the triple drug regimens. The discharge, sinuses and ulcers cleared in 6 months but the lymph nodes took longer to regress, up to 7 months in localized and 9 months in more widespread scrofuloderma. To obtain the same results with rifampicin and isoniazid, all patients with widespread scrofuloderma and one‐third of those with localized forms had to be treated for 10 and 9 months, respectively. No serious drug side‐effects, apart from giddiness with rifampicin and acneiform eruptions with thiacetazone, were encountered. No instances of relapse were noted in the 50% of patients who were followed‐up for 31/2 years after therapy. Single‐drug therapy with isoniazid for lupus vulgaris, as given in the past, is to be discouraged as it may promote the emergence of drug‐resistant bacilli in those with an undetected focus of infection. An additional object of defining effective mutliple drug regimens is to improve patient compliance by reducing the duration of therapy and to avoid confusion by adhering uniformly to the recommended regimen in places where tuberculosis is prevalent.