HLA-B and toxic epidermal necrolysis: From our prospective cohort, we also observed a single patient with allopurinol-induced SJS/TEN who carried HLA-B*58:02, an allele closely related to HLA-B*58:01 but differing by 3 amino acids in the peptide binding groove, which would not be detected by HLA-B*58:01–specific testing.