Atypical Type 2 Lepra Reaction Masquerading as Recurrent Sweet Syndrome.

Erythema nodosum leprosum (ENL) is an immune complex-mediated response in Mycobacterium leprae infection, presenting with fever, arthralgias, and tender cutaneous lesions. It mimics Sweet syndrome (SS) clinically and histologically but requires distinct management. A 65-year-old man with recent travel presented with fever and edematous plaques. Initial findings supported SS, improving with corticosteroids. Symptom recurrence and a contact's leprosy diagnosis led to further testing, revealing M. leprae through repeat staining and tissue PCR. This case underscores the need to consider ENL in Sweet-like cases with relevant travel history. Repeat staining and molecular testing are essential for accurate diagnosis and treatment.