TOXIC EPIDERMAL NECROLYSIS INDUCED BY PHENYTOIN: AN UNCOMMONLY USED ANTIEPILEPTIC DRUG IN HIGH-INCOME COUNTRIES

• Published in: Annals of allergy, asthma, & immunology Vol. 129; no. 5; p. S92
• Main Authors: Ratchataswan, T., Begue, R.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.11.2022
• ISSN: 1081-1206; 1534-4436
• DOI: 10.1016/j.anai.2022.08.758

Toxic epidermal necrolysis (TEN) is a rare, severe cutaneous adverse reaction; a form of type IV hypersensitivity, usually drug-induced. Phenytoin, an old antiepileptic, is strongly associated to TEN. Cases are rarely seen now, though, since phenytoin is rarely used in the U.S. We describe a patient with TEN provoked by phenytoin prescribed abroad. A 14-year-old female with past medical history of repaired meningocele and tethered cord complicated by CSF leak and meningitis at the age of 1 year old, had new onset of 2 episodes of tonic-clonic seizures, and was prescribed phenytoin and phenobarbital (the only 2 antiepileptics available in that Pacific Island). Three weeks later, she developed fever and bullous rash that rapidly spread to involve entire body including buccal, genital, and ocular mucosa. Antiepileptics were discontinued due to suspected TEN. Laboratory work-up was negative for autoimmune and multiple infectious etiology. She received meropenem and clindamycin but no immunologic therapy. On transfer to our institution, 2 weeks after, she was afebrile and most of the skin lesions were crusted and dried. Antibiotics were stopped and aggressive wound care, along with ophthalmology care for ocular adhesions, were provided. She was discharged 3 weeks after. TEN is a serious, urgent hypersensitivity condition. It must be promptly recognized, and the potential cause(s) identified and stopped to prevent further damage. The association with phenytoin is well established but rarely seen and poorly recognized by young trainees. This case provided a learning opportunity to all specialist in Allergy and Immunology.