For a study, researchers sought to characterize the incidence of Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) in a large unselected cohort, identify the culprit medicines implicated, and the frequency of SJS/TEN for each drug, and examine the clinical risk factors for SJS/TEN. They identified and verified all adult patients with a new SJS/TEN diagnosis between 1 January 2008 and 30 June 2019 using Clalit Health Services’ computerized database. The cumulative incidence of SJS/TEN for each culprit drug was estimated by dividing the total number of new users of the drug throughout the research period by the number of valid cases. For a nested case-control study, 20 controls were matched to each case by gender and age on the index date using risk-set sampling. The odds ratio and 95% confidence interval for the relationship of incident SJS/TEN with chronic illnesses were estimated using multivariable conditional logistic regression.

Between 1 January 2008 and 30 June 2019, they identified 87 adult instances of true/probable SJS/TEN. Culprit medicines [with ALDEN ratings of at least likely ( >4)] linked to the largest absolute hazards were phenytoin, lamotrigine, and allopurinol, with 3.56, 2.82, and 1.10 SJS/TEN cases/10,000 new users, respectively. Sunitinib, sulfasalazine, carbamazepine, etoricoxib, etodolac, and cefuroxime also had mean ALDEN ratings of 4, with cumulative incidences of 13.57, 0.72, 0.32, 0.05, 0.02, and 0.02/10,000 new users, respectively. Previous diagnosis of systemic lupus erythematosus, psoriasis, previous drug allergies, epilepsy, malignancy, history of cerebrovascular accident, and diabetes mellitus were all associated with an increased risk of SJS/TEN, with odds ratios (95 % CI) of 17.41 (1.31–230.72), 10.28 (3.61–29.31), 5.21 (2.95–9.19), 4.92 (1.88–12.85), 3.17 (1.77–5.66), 2.61 (1.26–5.41), and 1.98 (1.12–3.53), respectively.

Drugs with high ALDEN scores that were related to high absolute risks for SJS/TEN should be given special consideration. In the study, psoriasis, previous medication allergies, systemic lupus erythematosus, malignancy, history of cerebrovascular accident, and diabetes mellitus were all linked to an elevated risk of SJS/TEN.