As shown in Table 4, the HLA-B 58:01 allele occurred at significantly increased frequencies among the allopurinol-induced SJS-TEN patients compared to the two control groups (OR = 579.00, 95%CI: 29.50–11362.67 and OR = 238.40, 95%: 14.08–4037.80). This evidence concerns the gene HLA-B and toxic epidermal necrolysis.