Ethambutol Induced Lichenoid Drug Eruption: a case report.

BACKGROUND: A rare type of cutaneous adverse drug reaction (CADR), lichenoid drug eruption (LDE), can be associated with ethambutol.

CASE REPORT: A 60-year-old woman with spinal tuberculosis received multiple anti-TB medications and developed rashes after 3 months of the treatments. A skin biopsy from the posterior auricular area confirmed lichenoid dermatitis and the Naranjo causality assessment indicated ethambutol as a probable cause of LDE in the patient. The rashes slowly improved after discontinuation of ethambutol . Unfortunately, the residual of brown hyperpigmentation on the body has still persisted for over 16 months.

RESULTS AND CONCLUSION: The medications were reduced to isoniazid 300 mg/day and rifampicin 450 mg /day as planned for another 3 months. This case report points out the essentials of early recognition of ethambutol LDE by health care professionals.