A patch testing and cross-sensitivity study of carbamazepine-induced severe cutaneous adverse drug reactions

• Published in: Journal of the European Academy of Dermatology and Venereology Vol. 27; no. 3; pp. 356 - 364
• Main Authors: Lin, Y.-T., Chang, Y.-C., Hui, R.C.-Y., Yang, C.-H., Ho, H.-C., Hung, S.-I., Chung, W.-H.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-03-2013
• Subjects: Carbamazepine - adverse effects; Case-Control Studies; Drug-Related Side Effects and Adverse Reactions; Humans; Patch Tests; Skin - drug effects
• ISSN: 0926-9959; 1468-3083
• DOI: 10.1111/j.1468-3083.2011.04418.x

Background  The usefulness of the drug patch testing for Stevens–Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) is still controversial. Recent studies have shown that HLA‐B*1502 is strongly associated with CBZ‐SJS/TEN in Chinese and Southeast Asian populations.
Objective  To evaluate the usefulness of patch tests for patients with carbamazepine (CBZ)‐induced SJS, TEN and drug reaction with eosinophilia and systemic symptoms (DRESS) and the cross‐reactivity in patch tests among the aromatic antiepileptic drugs.
Methods  We measure the frequency of positive patch test reactions and cross‐sensitivity to structure‐related aromatic anti‐epileptic drugs (AEDs) for patients after SJS/TEN or DRESS episodes caused by CBZ. CBZ and other structure‐related AEDs used for patch testing were prepared in 10% and 30% petrolatum. Secondary measures included the association of HLA‐B*1502 genotype and frequency of possible side effects from the patch tests.
Results  Positive patch test reactions to 30% CBZ in the CBZ‐SJS/TEN were 62.5% (10/16), and 70% (7/10) in the CBZ‐DRESS. None of the 10 healthy controls displayed a positive reaction to tested agents. Cross‐sensitivity to other aromatic AEDs was observed in both the CBZ‐SJS/TEN and the CBZ‐DRESS. Only the HLA‐B*1502 genotype was present and strongly associated with the CBZ‐SJS/TEN, but not with the CBZ‐DRESS.
Conclusion  Drug patch testing is a safe and useful method for the identification of CBZ as the culprit drug of SJS/TEN as well as DRESS. Testing of chemically or pharmacologically related AEDs may provide information on cross‐reactivity for these patients.