What is Acute generalized exanthematous pustulosis?

Acute generalized exanthematous pustulosis is a rare skin reaction that in 90% of cases is related to medication administration.

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. The skin lesions usually resolve within 1–3 days of stopping the offending medication. 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.

Severe cutaneous adverse reaction 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 , toxic epidermal necrolysis 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 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.