Non-Healing Erythematous, Ulcerated Lesion On The Hand: A Quiz.

A 62-year-old woman, who worked as a seamstress, presented with an itchy, erythematous, scaly plaque on the dorsum of her fifth finger and the interdigital space 4/5 of her right, dominant hand. Physicians had diagnosed eczema 4 years previously, and had prescribed topical glucocorticosteroids. She reported having had breast cancer on the left side, which had been treated with mastectomy and adjuvant chemoradiotherapy 15 years previously, and had remained relapse-free. Differential diagnosis included skin cancer and chronic infection/inflammation. Biopsy revealed areas of dermalsubcutaneous necrobiosis surrounded by a granulomatous infiltrate exhibiting Langhans giant cells. PCR on paraffinsections was positive for Mycobacterium tuberculosis. The initial tuberculostatic regimen consisted of rifampicin 10 mg/kg/day, isoniazid 5 mg/kg/day, pyrazinamide 25 mg/kg/ day and ethambutol 15 mg/kg/day for a period of 2 months, to be continued with isoniazid and rifampicin for a further 4 months. The plaque improved with treatment, but did not resolve completely. At one year follow-up the patient presented with a progressive, ulcerated nodule at the same location (Fig. 1).