Symptoms of carbamazepine-induced SJS/TEN generally occur within one to three weeks after beginning carbamazepine treatment, and are caused by immune-mediated keratinocyte cell death, leading to detachment of the skin. In SJS, less than 10% of the body surface is affected, and it is fatal in up to 10% of cases. In TEN, which is fatal in up to 50% of cases, greater than 30% of the body’s surface is affected. Both conditions are characterized by epidermal detachment and severe mucous membrane erosion over the affected area of the body.
Development of carbamazepine-induced SJS and TEN is associated with the HLA-B*15:02 allele, which is most commonly found in Asian populations. Due to the low frequency of this allele in other populations, the FDA recommends testing for the presence of the HLA-B*15:02 in the high risk populations prior to beginning carbamazepine therapy.
- Hsiao YH, Hui RC, Wu T, et al. Genotype-phenotype association between HLA and carbamazepine-induced hypersensitivity reactions: strength and clinical correlations. J Dermatol Sci. 2014;73(2):101-9.
- Sukasem C, Chaichan C, Nakkrut T, et al. Association between HLA-B Alleles and Carbamazepine-Induced Maculopapular Exanthema and Severe Cutaneous Reactions in Thai Patients. J Immunol Res. 2018;2018:2780272.
- Amstutz U, Shear NH, Rieder MJ, et al. Recommendations for HLA-B*15:02 and HLA-A*31:01 genetic testing to reduce the risk of carbamazepine-induced hypersensitivity reactions. Epilepsia. 2014;55(4):496-506.