**3. AGEP**

AGEP is rare with an incidence of 1-5 cases per million per year. The clinical manifestations are characterised by fever and the rapid appearance of disseminated sterile pustules 3-5 days after the commencement of treatment. It is accompanied by a marked neutrophilia. Mucous membranes are not typically involved. The drugs conferring the highest risk of AGEP according to the EuroSCAR study are aminopenicillins, pristinamycin, hydroxychloroquine, antibacterial sulphonamides, terbinafine and diltiazem. The pathogenesis of AGEP involves the initial influx of CD8 cytotoxic T cells resulting in apoptosis of keratinocytes and formation of vesicles. Then CXCL-8 producing CD4 cells enter the epidermis resulting in neutrophil mediated inflammation and formation of pustules. As a result the histology reveals intraepi‐ dermal usually subcorneal pustules and an accompanying neutrophilic and lymphocytic infiltrate. Epicutaneous patch testing may also support the diagnosis by causing a localized pustular reaction 48-96 hours after the offending drug is applied. The condition usually resolves by 15 days after the causative drug is withdrawn but oral corticosteroid therapy may be necessary in some individuals. The mortality rate is up to 5% and mostly occurs in the elderly who have significant comorbidities.
