No cross-reactions between tetrazepam and other benzodiazepines: a possible chemical explanation

Drug patch testing in Stevens-Johnson syndrome and toxic epidermal necrolysis: A systematic review

BACKGROUND

The data on patch testing (PT) to identify culprit medications in Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) are limited to scattered case reports and small case series, without analysis of overall trends to inform clinicians of its utility, methodology, and safety.

OBJECTIVE

To conduct a systematic review of the practice of PT in SJS/TEN, quantify the positivity rate of common drug classes, and assess safety during testing.

METHODS

PubMed was searched from inception to 2021. Search terms included "patch testing" AND "SJS" OR "TEN" OR "Stevens-Johnson syndrome" OR "toxic epidermal necrolysis" OR "Lyell's syndrome."

RESULTS

There were 58 articles that met the inclusion criteria. In total, 82 patients underwent patch testing for SJS/TEN, resulting in 104 positive reactions to 49 unique medications. Antiepileptic drugs were responsible for 48.1% of the positive reactions; antibiotics, 28.8%; and nonsteroidal anti-inflammatory drugs, 6.7%. The positivity rates of antiepileptics, antibiotics, and nonsteroidal anti-inflammatory drugs were 33.1%, 13.1%, and 21.9%, respectively. When accounting for suspected causality, these rates increased to 54.3%, 78.4%, and 54.5%, respectively. Three patients (3.7%), 2 of whom had human immunodeficiency virus infection and active tuberculosis, experienced systemic reactions during PT, which required only conservative treatment.

CONCLUSION

Published reports suggest that PT in SJS/TEN is useful and safe. Antiepileptic drugs have been tested most frequently and found to have the highest positivity rate. There is a critical need for large-scale studies with standardized methodology to obtain reproducible data on PT in SJS/TEN.