LAUSR

Mycobacterium kansasii is the second most common cause of nontuberculous mycobacterial (NTM) lung disease after Mycobacterium avium complex infection in the United States.[1] The first-line therapy for M. kansasii is a three-drug regimen including rifampin, isoniazid, and ethambutol. We present a case of a patient with pulmonary M. kansasii who developed bullous skin lesions while receiving this regimen and again after rechallenge with ethambutol. In patients with intolerance to one of the first-line antibiotics, a multidisciplinary team approach to starting second-line agents is needed. Ethambutol should be included in the differential diagnosis of drug-induced bullous skin lesions in treated patients with NTM, who develop new onset rash with blisters or ulceration.