Acute generalized exanthematous pustulosis

Acute generalized exanthematous pustulosis (AGEP; also known as pustular drug eruption and toxic pustuloderma) is a rare skin reaction that in 90% of cases is related to medication.

AGEP is characterized by sudden skin eruptions that appear on average five days after a medication is started. These eruptions are pustules, i.e. small red white or red elevations of the skin that contain cloudy or purulent material (pus).^[1] The skin lesions usually resolve within 1–3 days of stopping the offending medication.^[2] However, more severe cases are associated with a more persistent disorder that may be complicated by secondary skin infections and/or involvement of the liver, lung, and/or kidney.^[3]

Severe cutaneous adverse reaction (SCAR) disorders are regarded as the drug-induced activation of T cells which then initiate innate immune responses that are inappropriately directed against self tissues. Studies on the DRESS syndrome, Stevens–Johnson syndrome (SJS), toxic epidermal necrolysis (TEN) and SJS/TEN overlap indicate that many individuals are predisposed to develop these reactions to a particular medication based on their genetically determined expression of particular human leukocyte antigen (i.e. HLA) alleles or T-cell receptors and/or their efficiencies in adsorbing, distributing to tissues, metabolizing, and/or eliminating) a particular SCARS-inducing medication. Evidence for these predispositions in AGEP has not been as well-established.^[2][4][5]