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 administration. 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 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 (pus).:124 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. SCARs 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, SJS, SJS/TEN, and TEN indicate that many individuals are predisposed to develop these reactions to a particular drug 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 drug. Evidence for these predispositions in AGEP has not been as well-established. AGEP is an acute drug eruption characterized by numerous small, primarily non-follicular, sterile skin pustules arising within large areas of red swollen skin usually within days of taking an inciting drug. The skin eruptions are often pruritic and accompanied by fever, headache, a high number of neutrophils and eosinophils in the blood, and elevated blood levels of markers for inflammation (i.e. erythrocyte sedimentation rate and C reactive protein). The skin eruptions typically end within a week after causative drug is discontinued. Rare cases of lung and bone marrow involvement have also been reported to complicate AGEP. However, involvement of these organs typically resolve along with the skin eruptions. AGE typically shows a mild course: usually, it is not associated with life-threatening complicates although superinfections of skin lesions may be serious or even life-threatening. AGEP has a mortality rate of less than 5%. About 90% of AGEP reactions are associated with medications. The remaining cases of AGEP have been associated with infective and other agents. The most frequently reported drugs that have been associated with the development of AGEP include penicillin, aminopenicillins, macrolides, quinolones, sulfonamides, hydroxychloroquine, terbinafine, and diltiazem. A more complete list of drugs sorted by their intended actions are: Infections with Parvovirus B19, mycoplasma, cytomegalovirus, coxsackie B4 virus, Chlamydophila pneumoniae, E. coli, and Echinococcus have been reported to be associated with the development of AGEP in the absence of an apparent drug-induced cause. The pathophysiology for the development of these drug-independent cases of AGEP is unclear. Viral infections have also been observed to be associated with the development of SJS, SJS/TEN, and TEN in the absence of a causative drug. Herbal medications, spider bites, iopamidol (used for radiocontrast), lacquers, mercury, psoralen (combined with ultraviolet A to treat psoriasis), and xenobiotics have been associated with the development of AGEP in case reports.