Acute generalized exanthematous pustulosis

Management Strategy

Treatment of AGEP involves establishing the correct diagnosis coupled with the withdrawal of any implicated medication ( Table 8.1 ). Pustular psoriasis is its main differential diagnosis. A comprehensive drug history and a personal or family history of psoriasis are therefore required.

Intraepidermal or subcorneal pustules in conjunction with a leukocytoclastic vasculitis, focal necrosis of keratinocytes, marked edema of the papillary dermis, and an infiltrate of eosinophils are histologic features that help distinguish AGEP from pustular psoriasis; biopsy is thus an integral facet of management.

Differentiation of AGEP from other inflammatory, toxic, or infectious conditions, such as Sneddon–Wilkinson disease (subcorneal pustular dermatosis) or, in severe cases, toxic epidermal necrolysis, is often readily apparent both clinically and histologically. The clinician should, however, be aware that erythema multiform–like targetoid lesions, mucous membrane involvement, facial edema, purpura, and vesiculobullous lesions have all been documented in the context of AGEP.

Antibiotics (primarily penicillin or macrolide based) are the most frequently implicated medications. Numerous case reports have cited various other causative agents, including calcium channel blockers, non-steroidal antiinflammatory drugs (NSAIDs), angiotensin-converting enzyme (ACE) inhibitors, and anticonvulsants ( Table 8.1 ). Acute enterovirus infection, mycoplasma pneumonia, cytomegalovirus, parvovirus B19, spider bites, Chinese herbal compounds (ginkgo biloba), contrast media, and mercury exposure have also been reported as possible causes.

There is no specific therapy for AGEP. A skin swab establishes the sterile nature of the pustules, and drug withdrawal, if feasible, results in rapid spontaneous resolution. Supportive therapy is all that is required. A superficial desquamation often occurs during this time and may be treated with simple emollients . Several case reports cite the use of patch testing to confirm the causative medication. Recalcitrant cases have benefited from oral prednisolone , ciclosporin , and secukinumab .