Generalised pustular psoriasis

generalised pustular psoriasis · GPP · von Zumbusch psoriasis · pustular flare

The emergency form of psoriasis - fever, widespread sterile pustules and a systemically unwell patient.

ADMITBand D

Red flags

Fever, hypotension or tachycardia - this can cause hypovolaemia, hypocalcaemia, acute kidney injury and sepsis
Extensive involvement or progression to erythroderma - thermoregulation and fluid balance fail
Recent withdrawal of systemic corticosteroid - the classic trigger
Pregnancy - impetigo herpetiformis is a pustular psoriasis of pregnancy with fetal risk and needs urgent obstetric and dermatology input
Secondary bacterial infection through broken skin

Recognise

On light skin

Sheets of small sterile pustules on bright red, tender, oedematous skin, coalescing into lakes, with fever and rigors.

On brown and black skin

The pustules are the tone-independent finding and remain visible as pale yellow-white points on any background, but the inflamed skin beneath may look violaceous, dark or simply swollen and glossy rather than red - so the striking contrast described in textbooks is muted, and the eruption can appear less dramatic than the patient's physiology. Judge severity on the fever, the tenderness, the extent and the observations rather than on redness.

In any skin tone

Fever and systemic upset with the eruption - this is not a cosmetic flare
Widespread sterile pustules coalescing into lakes of pus
Painful, tender skin
Often a known history of psoriasis, and frequently a trigger: corticosteroid withdrawal, infection, pregnancy, or drugs
May progress to erythroderma with the same physiological consequences

Distribution

Widespread sheets of small sterile pustules on inflamed skin, often coalescing into lakes of pus, over the trunk and limbs including the flexures.

Photographs

Generalised pustular psoriasis in two patients. (A) Sheets of confluent erythema studded with pustules that have run together into a 'pustul — Generalised pustular psoriasis in two patients. **(A)** Sheets of confluent erythema studded with pustules that have run together into a **'pustular lake'**, with superficial scaling at the edge. **(B)** Hundreds of discrete pustules on an inflamed base. The pustules are **sterile** - this is not an infection, and swabbing it will mislead you - but the patient is genuinely unwell with fever and a raised CRP, can lose fluid and heat through the skin, and needs admission and dermatology the same day. Do not mistake it for extensive impetigo.
Fitzpatrick III (Fitzpatrick type estimated from the photograph, not stated by the source) · Bachelez H, Acta Dermato-Venereologica · Bachelez H. Pustular Psoriasis: The Dawn of a New Era. Acta Derm Venereol 2020;100, Figure 1 · CC BY-NC

Provenance for every photograph in this library: image licences. How much of the corpus still has no darker-skin photograph: skin tone coverage.

Mimics

Acute generalised exanthematous pustulosis — The key differential. AGEP follows a new drug within days and settles on stopping it; pustular psoriasis usually has a psoriasis history and a different trigger. Histology and the drug timeline separate them, and the distinction matters because the treatments diverge
Psoriasis, including guttate — The same disease in its emergency form
Erythroderma — Pustular psoriasis frequently becomes erythrodermic
Stevens-Johnson syndrome / toxic epidermal necrolysis — Both give widespread painful skin with fever; necrolysis detaches epidermis and erodes mucosa rather than forming pustules

What to do in the ED

Treat as an acute medical emergency, not a rash: observations, fluid balance, and bloods including renal function, calcium, albumin and CRP
Swab a pustule to confirm sterility and exclude bacterial infection
Take a careful drug history covering the preceding weeks, specifically asking about stopping a systemic steroid as well as starting anything new
NICE CG153 1.2.1.11 is explicit: people with generalised pustular psoriasis or erythroderma should be referred immediately for same-day specialist assessment and treatment - and CKS classes both as rare medical emergencies that may be life-threatening. Admit - this is not a discharge diagnosis
Warm the patient, replace fluids, and manage the skin as a barrier failure with emollient and non-adherent dressings
Do not start or stop systemic corticosteroids without dermatology advice, as both can worsen the disease
In pregnancy, involve obstetrics urgently

Disposition

ADMIT

Admit with same-day dermatology. Critical care input if thermoregulation, fluid balance or renal function are failing.

Sources

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