An 18-year-old male presented with painful papulo-nodular lesions on the upper limbs and back along with high-grade fever since 1 week. Most lesions had a lichenoid center with surrounding blisters ([Figure 1A](#f1){ref-type="fig"}). There was associated tenderness and thickening of bilateral ulnar nerves. Slit skin smear was positive for *Mycobacterium leprae* (with a bacteriological index of 6+ and a morphological index of 0%) ([Figure 1B](#f1){ref-type="fig"}). Skin biopsy revealed features of lepromatous leprosy (LL) with erythema nodosum leprosum (ENL) including granulomas, nerve destruction, vasculitis, and panniculitis, and lepra stain was positive ([Figure 1C](#f1){ref-type="fig"}). Over the next 2 weeks, most lesions developed ulceration, suggesting necrotic ENL ([Figure 1D](#f1){ref-type="fig"}). The patient is currently receiving WHO-recommended multidrug therapy (MDT) with oral corticosteroids.

![(**A**) Patient with multiple papulo-nodules, having a lichenoid center with surrounding blisters, on upper limb and back. (**B**) Slit skin smear of the same patient showing acid fast bacilli. (**C**) Histopathological examination of skin biopsy showing granulomatous inflammation and vasculitis. (**D**) Same patient with ulcerative changes in lesions within 2 weeks, suggesting necrotic ENL. This figure appears in color at [www.ajtmh.org](http://www.ajtmh.org).](tpmd200177f1){#f1}

Erythema nodosum leprosum is a type III hypersensitivity reaction presenting as erythematous, tender papulo-nodules, commonly on extremities, with histology showing granulomatous inflammation with neutrophil infiltration, and variable degrees of panniculitis and vasculitis.^[@b1],[@b2]^ Reported incidence of ENL in multibacillary leprosy (especially LL) is as high as 11.8%.^[@b3]^ The lesions usually appear after starting MDT, although it may sometimes be the presenting feature.^[@b4]^ Rarely, ENL may be associated with ulceration, producing necrotic ENL, also called erythema necroticans. Necrotic ENL is a severe form often associated with systemic complications and heals with scarring.^[@b5]^ The case illustrates that lichenoid skin nodules may be an unusual initial presentation of necrotic ENL.

We thank Bishan Das Radotra for his inputs regarding histopathological diagnosis.

[^1]: Authors' addresses: Akanksha Kaushik, Sunil Dogra, and Tarun Narang, Department of Dermatology, Venereology and Leprology, Postgraduate Institute of Medical Education and Research, Chandigarh, India, E-mails: <akskaushikk@gmail.com>, <sundogra@hotmail.com>, and <narangtarun@yahoo.co.in>.
