A risk of association was observed between HLA-A*02:01/Cw15:02 and PHT-induced SJS/TEN (Group-B OR = 14.75, p = 0.009; G-C OR = 27.50, p < 0.001).HLA-B*38:01 and PHT-LTG (Group-A OR = 12.86, p = 0.012; G-B OR = 13.81, p = 0.002; G-C OR = 14.35, p < 0.001), and LTG (G-A OR = 147.00, p = 0.001; G-B OR = 115.00, p < 0.001; G-C OR = 124.70, p < 0.001).HLA-A*11:01 and CBZ (G-A OR = 63.89, p = 0.002; G-B OR = 36.33, p = 0.005; G-C OR = 28.29, p = 0.007). This evidence concerns the gene HLA-B and toxic epidermal necrolysis.