Acute generalized exanthematous pustulosis induced by sulfasalazine: Uncommon presentation of a common culprit

Abstract

Acute generalized exanthematous pustulosis (AGEP) is a severe cutaneous adverse drug reaction caused by drugs in the majority of cases. It is characterized by the sudden onset of nonfollicular sterile pustules, papules, and edematous plaques on an erythematous background, predominantly involving the flexures. Sulfa drugs have a notorious reputation of wide range of severe adverse reactions, including AGEP. However, nonantibiotic sulfonamides behave differently from antibiotic sulfonamides in the pattern of adverse drug reactions and seldom cause AGEP. Only one case of AGEP due to salazosulfapyridine has been documented, none due to sulfasalazine. We report a 40-year-old female patient with a known case of reactive arthritis who was started on tablet sulfasalazine 500 mg in escalating doses, 4 days before the onset of nonfollicular sterile pustules, on erythematous background predominantly over flexures. She was diagnosed as a case of definite AGEP with score of 12/12 on the European Study of Severe Cutaneous Adverse Reaction validation scale. As per the Naranjo causality scale, sulfasalazine was the probable drug with a score of 5.