Generalized pustular psoriasis in Adult
Alerts and Notices
Synopsis

There are 3 subtypes of GPP:
- von Zumbusch type (GPP) – Acute onset of generalized erythema and pustules with systemic manifestations including fever, skin tenderness, malaise, arthralgias, headache, and nausea. After several days, the pustules resolve to become confluent, scaling plaques.
- Exanthematic type – Acute onset of small pustules that are triggered by an infection or a drug. This subtype usually lacks systemic symptoms.
- Annular subtype – Erythematous, annular lesions that have pustules at the advancing edge of a lesion and is associated with fever, malaise, and other systemic manifestations. The annular variant is the most common form of pustular psoriasis in children.
GPP can also present in infants and children, and these patients may have a known genetic mutation. Genetic associations involving interleukin-36 receptor antagonist (IL36RN); the keratinocyte nuclear factor κB adaptor protein, CARD14; and adaptor protein 1 complex, subunit 3 (AP1S3) have been discovered in European, Asian, and Pakistani populations. These may be inherited in a homozygous compound or simple heterozygous state. IL36RN mutations are most frequently associated with early-onset pustular psoriasis. Mutations in SERPINA1 and SERPINA3 have also been associated with pustular psoriasis.
Pustular psoriasis may be preceded by or may coexist with plaque psoriasis. Pustular flares can be induced by infection (Trichophyton rubrum, cytomegalovirus, Streptococcus spp, varicella-zoster, and Epstein-Barr virus), a rapid withdrawal of corticosteroids, pregnancy, medications (NSAIDs, lithium, potassium iodine, trazodone, penicillin, interferon, and hydroxychloroquine), and topical irritants such as tar and anthralin. More recently, COVID-19 infection has been shown to trigger pustular flares of psoriasis.
While tumor necrosis factor (TNF)-alpha antagonists such as infliximab and adalimumab are used to treat pustular psoriasis, they have also been reported, paradoxically, to induce it.
Patients may experience relapses and remissions over a period of years. It may be precipitated by use and withdrawal from systemic corticosteroids.
Extracutaneous manifestations of pustular psoriasis may be severe and are associated with a great deal of morbidity and mortality. The most common extracutaneous manifestations of pustular psoriasis include cholestasis, cholangitis, arthritis, intestinal pneumonitis, oral lesions, and acute renal failure. Electrolyte disturbances such as hypocalcemia may occur and can be life-threatening. Lesions may also become superinfected.
Codes
ICD10CM:L40.1 – Generalized pustular psoriasis
SNOMEDCT:
238612002 – Generalized pustular psoriasis
Look For
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Diagnostic Pearls
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Differential Diagnosis & Pitfalls
- AGEP – Clinically indistinguishable from pustular psoriasis. Time of onset and a drug history may help differentiate AGEP from pustular psoriasis. Antibiotics are the likely causative agents in AGEP. Histology can also help differentiate between those diagnoses. Also look for high fever, edema of the face, pustular eruption that occurs shortly after drug administration (fewer than 2 days), marked serum leukocytosis with neutrophilia, and associated petechiae, purpura, and vesicles in AGEP.
- Toxic epidermal necrolysis (TEN)
- Drug reaction with eosinophilia and systemic symptoms (DRESS) – Look for marked eosinophilia, visceral involvement (most commonly hepatitis), less acute onset, facial edema, and atypical lymphocytosis.
- Subcorneal pustular dermatosis (Sneddon-Wilkinson disease) – Associated with immunoglobulin A (IgA) paraproteinemia and is very responsive to dapsone. Pustular psoriasis is not responsive to dapsone and does not have an IgA paraproteinemia.
- Erythema annulare centrifugum – To be considered when annular-type psoriasis is observed. No associated systemic findings. Individual lesions can last for months.
- Disseminated herpes simplex infection
- Eczema with secondary infection
Best Tests
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Management Pearls
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Therapy
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Drug Reaction Data
Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.Subscription Required
References
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Last Reviewed:02/01/2023
Last Updated:02/09/2023
Last Updated:02/09/2023

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