Erythema induratum in a Kenyan child

A 10-year-old Kenyan girl presented with a 9-month history of a persistent, painful eruption of multiple, tender, non-ulcerated, pigmented nodules involving the calves, shins and soles of the feet. She had recurring fevers particularly at night, lethargy, weight loss and a persistent non-productive cough. The Mantoux test was positive. Chest X-ray revealed mild peribronchial thickening in the hilar region but no evidence of hilar lymphadenopathy, consolidation and/or cavitation suggestive of tuberculosis. Sputum and gastric washings were negative for acid-fast bacilli. Histology on a skin biopsy showed a granulomatous panniculitis with no histological evidence of Mycobacterium tuberculosis, consistent with erythema induratum. In view of her constitutional symptoms, chronic non-productive cough and positive Mantoux test, she was diagnosed with pulmonary tuberculosis despite the non-specific chest X-ray and negative bacteriology. Anti-tuberculous therapy was initiated with pyrazinamide, isoniazid and rifampicin for 2 months followed by dual therapy with isoniazid and rifampicin for a further 4 months. Her constitutional and respiratory symptoms and skin eruption cleared within 6 months with treatment.