HLA-B and Scarring: HLA-B*58:01 diplotypes (homozygous or heterozygous) were present in 5.9% of the population studied, indicating significantly increased risk of allopurinol-induced severe cutaneous adverse reaction (SCAR), which is manifested by Stevens–Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), or drug reaction with eosinophilia and systemic symptoms (DRESS)40.