Successful treatment of erythema induratum with topical application of antituberculous drugs

RATIONALE Erythema induratum, a chronic recurrent lobular panniculitis with vasculitis, is strongly associated with Mycobacterium tuberculosis infection. The recommended drugs include isoniazid, rifampicin, and pyrazinamide, which are typically administered in combination (orally or intravenously). Till date, there are no reports about topical application of anti-tuberculous (anti-TB) drugs for treatment of erythema induratum. PATIENT CONCERNS Herein, we present the case of a 73-year-old woman with recurrent ulceration, scarring and obvious pain in her lower legs. DIAGNOSES She was diagnosed of erythema induratum. INTERVENTIONS Topical anti-TB treatment (3.75% isoniazid twice a day) was necessitated by the development of severe gastrointestinal upset and significant reduction in platelets after oral treatment with isoniazid and rifampicin. OUTCOMES The skin lesions showed improvement at one month and remitted mostly at two months. After 6 months, the skin lesions have subsided and no obvious side effects were observed. LESSONS Our experience may help expand the therapeutic regimens for cutaneous tuberculosis, and provide physicians with alternative options for management of tuberculosis.