Approximately 85% of TEN cases are induced by drugs.[4] The primary sensitizing drugs associated with TEN include antibiotics, anticonvulsants, antiviral drugs, and traditional Chinese medicine.[3] Recent studies have found that the occurrence of TEN is related to the individual human leukocyte antigen (HLA) allele genotype.[5,6,7] The HLA complex consists more than 200 genes on chromosome 6 can be categorized into 3 subgroups: Class I HLA, being recognized by CD8+ T cells, consists of 3 main genes, that is HLA-A, HLA-B, and HLA-C. This evidence concerns the gene CD8A and toxic epidermal necrolysis.