Erythema necroticans: A presenting manifestation of silent leprosy

Leprosy reactions are rare expression of immunological perturbations that interrupt the usual chronic course and the clinical stability of patients with leprosy. Erythema nodosum leprosum (ENL) is an immune complex-mediated reaction that may complicate the course of multibacillary leprosy. It generally occurs during antimycobacterial treatment and characterized by the appearance of crops of brightly erythematous tender nodules or plaques. Severe ENL can become vesicular or bollous and break-down and is termed erythema necroticans [Jobling, W.H., Mc Dougall, A.C., 1996. Leprosy reactions. In: Handbook of leprosy, 5th ed. CBS Publishers, New Delhi, pp. 82–91]. We present here a case of erythema necroticans, misdiagnosed as sweet’s syndrome, because he had never been presented with pre-existing evidence of leprosy nor had any antimycobacterial treatment. The clinical diagnosis is confirmed by microscopic pathology. The lesions resolved completely following multibacillary MDT, corticosteroids and Azathioprine.