Ethambutol induced bullous and lichenoid skin eruptions

Introduction: Ethambutol is an essential drug for tuberculosis treatment. It has been in use since 1961. Its major side effect is on visual system, cutaneous side effects are rarely descripted in the literature including purpura, pruritic erythematous papules and exfoliative dermatitis. Materials and methods: We report one case of ethambutol induced bullous and lichenoid skin rashes confirmed by provocation test. Results: It9s about 73 years old woman, diabetic,treated of lung tuberculosis with Isoniazid, Rifampicin, pyrazinamid and ethambutol. After 25 days for treatment she reported generalised itching. Cutaneous examination revealed vesiculo-bullous eruptions on chest and abdominal wall, hyperpigmented face and diffuse desquamation on the limbs. All anti tuberculosis drugs were stopped and patient was put on local corticosteroid therapy for two weeks. The lesions cleared completely. Because of its low risk of entraining skin side effect, ethambutol was introduced the first drug in a dose of 20 mg/kg. 24 hours later this provocation test, generalised itching and erythematovisicular skin eruptions more marked on the extremities were appeared, further administration of ethambutol was stopped. Patch tests will be programmed when lesions disappeared. Clinician should be alerted to consider ethambutol also as one of possible drug causing cutaneous eruptions.