Evidence Levels:  A Double-blind study  B Clinical trial ≥ 20 subjects  C Clinical trial < 20 subjects  D Series ≥ 5 subjects  E Anecdotal case reports

Acute generalized exanthematous pustulosis (AGEP) is characterized by the acute onset of numerous small, non-follicular, sterile pustules arising on a diffuse erythematous base in a febrile patient with an accompanying blood neutrophilia. The majority of cases occur in the context of drug ingestion (commonly within 24 hours). Rapid resolution following drug withdrawal is the usual outcome.

(From Roujeau, et al., 1991. Arch Dermatol 127, 1333–1338.)

Intraepidermal or subcorneal pustules in conjunction with a leukocytoclastic vasculitis, focal necrosis of keratinocytes, marked oedema of the papillary dermis, and an infiltrate of eosinophils are histological 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 multiforme-like targetoid lesions, mucous membrane involvement, facial edema, purpura, and vesicobullous 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 anti-inflammatory drugs (NSAIDs), angiotensin-converting enzyme (ACE) inhibitors and anticonvulsants (Table 8.2). Acute enterovirus infection, 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. Only a single case report supports the use of systemic corticosteroids for this self-limiting condition.