Allopurinol hypersensitivity syndrome (AHS) typically occurs in persons with preexisting kidney failure.

[1] In a retrospective case-control study, it was shown that an increased initial dose of allopurinol was linked to AHS.

[9] Additionally, among the most common co-morbidities in a comprehensive analysis of all 901 reported cases of AHS, chronic kidney disease was present in 182 out of 376 (48%) patients.

An odds ratio of 80–580 has been reported to link the HLA-B*58:01 allele to a higher risk of allopurinol-induced DRESS and SJS/TEN.

Whether a patient has toxic epidermal necrolysis, Stevens-Johnson syndrome, or drug reaction with eosinophilia and systemic symptoms will determine the course of treatment.