Leprosy misdiagnosed as Sweet syndrome: A case report

A 40-year old woman presented with recurrent fever and painful erythematous plaques over the limbs for two years. Clinical features and laboratory investigations, including neutrophilia and elevated inflammatory markers, were suggestive of Sweet syndrome; skin biopsy ultimately diagnosed borderline lepromatous leprosy with erythema nodosum leprosum; Fite-Faraco staining also showed a bacillary index of 4+ to 5+ . Peripheral nerve examination showed mild enlargement of the right ulnar and left common peroneal nerves; slit-skin smear showed a bacillary index of 4+ . Ocular, mucosal, disability and contact evaluation were unremarkable. Multidrug therapy with corticosteroids resolved lesions within two weeks of hospitalisation; contact tracing was negative. She was free of ENL lesions at four weeks, then lost to follow-up. This case shows that biopsy was key to diagnosing leprosy misdiagnosed clinically as Sweet syndrome, and that this diagnosis warrants complete clinical evaluation for complications, not antibacterial treatment alone.