Rifampicin-induced lichenoid eruptions

A 65-year-old man presented with generalised pruritic skin lesions of 1 month duration. He had a positive pulmonary tuberculosis smear and was on antituberculosis therapy, which included isoniazid, rifampicin, ethambutol and pyrazinamide, for 1 month. His medical history was otherwise unremarkable. He had no significant skin ailments or allergic tendencies in the past. General physical examination revealed multiple erythematous, pruritic eruptions over the patient's back (figure 1), anterior chest and arms. Haemogram showed marked peripheral eosinophilia (26.8%) with an absolute eosinophil count of 3042. The rest …