Type 2 lepra reaction as a cause of pyrexia of unknown origin.

Leprosy, a commonly encountered disease, can rarely present as a reactional state de novo with fever as the main presenting feature. Here we describe an uncommon presentation of leprosy [with type 2 lepra reaction] as pyrexia of unknown origin with prominent rheumatologic manifestations [acute polyarthritis], renal involvement and generalized lymphadenopathy with rare presentation of type 2 lepra reaction without the classic skin lesions of erythema nodosum leprosum, occurring in a treatment naive patient without prior history of leprosy.