Type 1 lepra reaction in histoid leprosy

ObjectivesLepra reaction in histoid leprosy (HL) is rare; there are few reports of type 2 lepra reaction in HL. We report a 42-year-old woman with HL in type 1 lepra reaction after 10weeks of multibacillary multi-drug therapy (MBMDT). Case reportA 42-year-old woman presented with asymptomatic multiple papules, plaques, and nodules over the face, trunk, and extremities and no history of prior treatment with anti-leprosy drugs. A biopsy of a skin nodule on the forearm revealed spindle-shaped, non-vacuolated histiocytes in a whorled pattern with abundant acid-fast bacilli (AFB). The patient was diagnosed with HL and started on MBMDT. Ten weeks later, she developed pruritic, painful, erythematous, and edematous papules, plaques, and nodules over the face, trunk, and extremities, without constitutional symptoms. Histopathology revealed an atrophic epidermis, preserved grenz zone, and papillary dermal edema. Elongated AFB were visible on Fite's stain. The MBMDT was continued, along with nonsteroidal anti-inflammatory drugs and antihistamines, but pruritus, pain, erythema, and edema persisted, and new skin lesions appeared. The patient was started on prednisolone at 0.75mg/kg body weight/day. Prednisolone resulted in symptomatic relief and the healing of ulcerated papules within fourweeks. Treatment was tapered and stopped after 20weeks. ConclusionsHistoid leprosy is considered a variant of lepromatous leprosy, which rarely involves a lepra reaction. Pruritus and ulceration of skin lesions as manifestations of type 1 lepra reaction in HL have not been reported previously. These symptoms manifested after 10weeks of MBMDT and responded well to oral prednisolone.