WEDNESDAY, June 21, 2023 -- Currently used approaches to identify culprit drugs in Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) may overlabel patients as allergic to likely nonculprit drugs and may also miss possible culprit drugs, according to a study published online June 21 in JAMA Dermatology.

Dayan J. Li, M.D., Ph.D., from Brigham and Women's Hospital in Boston, and colleagues examined patient allergy list outcomes and current approaches in identifying culprit drugs in a retrospective cohort study spanning 18 years and including 48 patients with clinically and histologically confirmed cases of SJS/TEN overlap and TEN.

The researchers found that the mean number of drugs taken per patient was 6.5 at disease onset. Seventeen patients were labeled as allergic to a single culprit drug; however, across all patients, 104 drugs were added to allergy lists. Physicians' approaches mainly relied on heuristic identification of high-notoriety drugs and drug exposure timing. Sensitivity was improved using a vetted database for drug risk. In 28 cases, Algorithm for Drug Causality for Epidermal Necrolysis scoring was discordant, resulting in an additional nine drugs being labeled that were missed by physicians and clearing 43 drugs that physicians labeled as allergens. Twenty cases could potentially have been affected by human leukocyte antigen testing. There was limited consideration of infection as a culprit.

"It is important to identify a culprit drug in SJS/TEN as accurately as possible. In the absence of a criterion standard laboratory test, the onus is on clinicians to make that determination," the authors write. "This study's data suggest that culprit drug identification is commonly very challenging."

Two authors disclosed ties to the biopharmaceutical industry; one had a provision patent issued outside the submitted work.