Abstract: This report describes a case of levofloxacin-induced toxic epidermal necrolysis (TEN) occurring during antituberculosis therapy. A patient developed active pulmonary tuberculosis following treatment for lung cancer and subsequently experienced a rare and potentially fatal case of toxic epidermal necrolysis induced by anti-tuberculosis drugs. In clinical management, suspicious medications were immediately discontinued, and an analysis using the Algorithm of Drug Causality for Epidermal Necrolysis identified levofloxacin as the causative drug. The Severity-of-Illness Score for Toxic Epidermal Necrolysis estimated the patient's mortality risk at 62%. To manage TEN, the treatment team initiated a combination of corticosteroids, immunoglobulins, and TNF-α antagonists, while concurrently starting intensive second-line anti-tuberculosis therapy. This approach effectively reduced the risk of tuberculosis dissemination triggered by immunotherapy. Following the resolution of TEN, a drug provocation test was performed to evaluate the patient's tolerance to isoniazid, ethambutol, and pyrazinamide, which subsequently informed the formulation of a revised anti-tuberculosis regimen. This case underscores the rare and severe risk of TEN induced by levofloxacin and provides valuable insights into the management of pulmonary tuberculosis complicated by TEN.

Key words: Toxic epidermal necrolysis, Tuberculosis, Levofloxacin