A double blow for a patient with leprosy: a reversal reaction and an adverse drug reaction

A 28-year-old man from the rural area of Tamil Nadu attended our specialist hospital, complaining of multiple, copper-coloured patches on his skin, forehead, arms, and the front and back of his torso (figure). On examination he also had bilateral thickening of his ulnar and median nerves, without any functional impairment; multiple slit skin smear tests were positive for acid-fast bacilli in most of the patches on his body. We made a diagnosis of multibacillary, or lepromatous, leprosy, and started the patient on a 12-month course of multidrug therapy (MDT)—rifampicin 600 mg once a month, dapsone 100 mg daily, and clofazimine 300 mg once a month and 50 mg daily. However, within a month, the patient developed raised erythematous lesions over the pre-existing skin patches (figure) as well as general constitutional symptoms including a fever and severe neuritis. A full blood count was normal and serological testing for any additional infections was negative. Biochemical investigations showed abnormal liver function tests (appendix). On the basis of these findings, we made a diagnosis of a severe type 1 leprosy reaction—also known as a reversal reaction—occurring alongside an adverse reaction to dapsone. The patchy, exfoliative dermatitis along with the swollen lips, fever, and hepatitis were key in reaching a diagnosis of an adverse reaction to dapsone. We stopped the MDT regimen, and started the patient on corticosteroids, beginning with a high dose and tapering over subsequent weeks—the hope was that the steroids would help both the adverse reaction to the dapsone and the reversal reaction. At follow-up visits, the patient showed improvement both clinically and biochemically, as indicated by the liver function tests (appendix). We restarted the MDT regimen but this time excluded the dapsone.