Pustular psoriasis in Adult
There are 4 subtypes of pustular psoriasis:
- In the von Zumbusch type, there is an 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.
- The exanthematic type is characterized by the acute onset of small pustules that are triggered by an infection or a drug. This subtype usually lacks systemic symptoms.
- The annular subtype is characterized by erythematous, annular lesions that have pustules at the advancing edge of a lesion and is associated with fever, malaise, and other systemic manifestations.
- The localized pattern occurs when pustules appear in existing psoriatic plaques. This can be seen in active plaques.
Patients may experience relapses and remissions over a period of years. There is no racial predilection. Pustular psoriasis may occur in children but is more commonly seen in middle-aged adults. It may be precipitated by use and withdrawal from systemic corticosteroids (for example, weeks after an IM injection).
Fever and arthritis may be prominent features in the immunosuppressed patient. There may be an inflammatory polyarthritis with associated involvement of the plantar fascia and Achilles tendon. Relapses and remissions may occur over a period of years. It may be precipitated by use and withdrawal from systemic corticosteroids (eg, weeks after an IM injection).
Note: Only in rare cases, such as erythroderma or severe pustular psoriasis, should oral steroids be considered. This is because the use of systemic steroids will lead to severe psoriasis rebound after steroid discontinuation.
For more information on generalized pustular psoriasis, see OMIM.
L40.1 – Generalized pustular psoriasis
200973000 – Pustular psoriasis
- Acute generalized exanthematous pustulosis (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 the two. 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
- 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 IgA paraproteinemia and is very responsive to dapsone. Pustular psoriasis is not responsive to dapsone and does not have an IgA paraproteinemia.
- Keratoderma blennorrhagicum seen in reactive arthritis disease – Look for characteristic associated findings including urethritis, arthritis, and ocular findings.
- Dyshidrotic eczema – Extremely pruritic, restricted to hands and feet, look for deep-seated vesicles that look like tapioca pudding.
- Erythema annulare centrifugum – To be considered when annular-type psoriasis is observed. No associated systemic findings. Individual lesions can last for months.
- Impetigo herpetiformis – Pustular psoriasis during pregnancy.
- Disseminated herpes simplex