Background:Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are part of the spectrum of one of the most serious dermatological conditions that occur in the hospital setting, considered a dermatological emergency. Stevens-Johnson syndrome is called toxic epidermal necrolysis (TEN) when ≥30% of the body surface is affected, and it is the most serious form of the disease, with adverse drug reactions being the main etiology, up to 80%. Clinical case:We present the clinical case of a 30-year-old male, with a history of systemic arterial hypertension, who began with symptoms after taking allopurinol after being diagnosed with hyperuricemia. It began with a picture of bilateral conjunctivitis, followed by a sudden appearance of localized dermatosis on the face, characterized by erythematous plaques with indistinct, non-painful borders, and later the appearance of ulcers and blisters, extending to 70% of the body surface. During his hospitalization, he developed a lesion acute renal failure, managed by the intensive care service, with total remission upon discharge and favorable response to treatment thanks to multidisciplinary management. Treatment was provided with human immunoglobulin, vancomycin-based antibiotic therapy, and ciprofloxacin for impetiginization of facial ulcers, fluid therapy, Vaseline gauze dressings, and topical ophthalmological treatment, achieving discharge without comorbidities. Conclusion:Toxic epidermal necrolysis is a severe picture of Steven Johnson Syndrome, potentially fatal, which requires early multidisciplinary management that leads to the recognition and management of associated comorbidities in a timely manner.Key words: Stevens-Johnson syndrome; toxic epidermal necrolysis; halopurinol, drug reaction.