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


CONCLUSIONS
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.
Department of Dermatology, Chang Gung Memorial Hospital, Taipei, Linkou, Keelung, and Chang Gung University College of Medicine, and Institute of Pharmacology, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
Y-T
YT
Lin
Y-C
YC
Chang
R C-Y
RC
Hui
C-H
CH
Yang
H-C
HC
Ho
S-I
SI
Hung
W-H
WH
Chung
D002220:Carbamazepine / Q000009:adverse effects*; D016022:Case-Control Studies; D064420:Drug-Related Side Effects and Adverse Reactions; D006801:Humans; D010328:Patch Tests; D012867:Skin / Q000187:drug effects*
D002220:Carbamazepine