Stevens-Johnson syndrome/toxic epidermal necrolysis overlap following sulfadoxine-pyrimethamine overdose: a case report

Abstract

Stevens-Johnson syndrome/toxic epidermal necrolysis overlap is a rare but severe delayed-type hypersensitivity reaction that presents with widespread blistering, ulceration and necrosis of the skin and mucosa in the genetically predisposed and leads to significant morbidity and mortality. Sulfadoxine-pyrimethamine has been reported to cause a spectrum of drug hypersensitivity reaction (Stevens-Johnson syndrome, toxic epidermal necrolysis or Stevens-Johnson syndrome/toxic epidermal necrolysis overlap), but in rare occasions, hence this report. We report a 5-year-old boy who presented with fever and extensive mucocutaneous blistering and ulcerations 10 days following the ingestion of an overdose of sulfadoxine-pyrimethamine administered by a community health extension worker. Skin involvement was about 19%. The Naranjo Adverse Drug Reaction Probability Scale score of 6 was assigned (implying probable association between the ingested drug and the hypersensitivity reaction). The severity-of-illness score of toxic epidermal necrolysis of 1 was also assigned to this patient (implying low severity). He was managed conservatively with fluid, antibiotics, nutritional support and wound care measures. He recovered completely and satisfactorily. The patient's sister and father had reacted similarly but less severely when exposed to sulfadoxine-pyrimethamine. Health workers should pay close attention to every patient's family drug allergy history before administering any medications. Also, basic pharmacogenetic testing should be introduced into health facilities, especially for drugs known to cause serious adverse drug reactions. Furthermore, health workers should keep abreast with updates on treatment guidelines and also dutifully report all cases of adverse drug reactions to relevant bodies.