Criteria of Singer and Wallace for the Allopurinol Hypersensitivity Syndrome (Allopurinol-Related DRESS)

 

Criteria for the diagnosis of AHS:

(1) one of the following:

(1a) 2 or more major criteria

(1b) 1 major and 1 or more minor criteria

(2) documented exposure to allopurinol

(3) exclusion of an alternative explanation (exposure to a different drug associated with the drug rash with eosinophilia and systemic symptoms (DRESS)

 

Major criteria:

(1) deterioration in renal function

(2) acute hepatocellular injury

(3) any of the following: toxic epidermal necrolysis, erythema multiforme, diffuse maculopapular rash, exfolliative dermatitis

 

Minor criteria:

(1) fever

(2) leukocytosis

(3) eosinophilia