Acute pustular psoriasis

Acute pustular psoriasis is a potentially life threatening disease characterised by the development of numerous small sterile yellow pustules and widespread areas of erythema. The pustules may coalesce to form large patches of pus.

The condition may arise in patients who have had classical psoriasis for many years. Attacks may be precipitated by infection, drugs, pregnancy, or the withdrawal of topical or systemic corticosteroid therapy.

The patient may present with a high, swinging fever of non -infective origin, but secondary infections may occur (and is potentially lethal).

Click here for example images of pustular psoriasis

Subtypes of generalized pustular psoriasis:

• Generalized: von Zumbusch subtype: Diffuse generalized pustular eruption with associated systemic symptoms (fevers, arthralgias, etc.)
  
  
• Annular subtype: Annular lesions with pustules along the advancing edge
  
  
• Exanthematic subtype: Acute pustular eruption that disappears after a few days without systemic symptoms
  
  
• Impetigo herpetiformis: Pustular psoriasis occurring during pregnancy

Causes of acute pustular psoriasis:

• most cases of pustular psoriasis are idiopathic, however, risk factors that may have a role in the aetiology of pustular psoriasis include (1):
  • sudden withdrawal of systemic steroids
  • skin infections (Staphylococcus aureus)
  • electrolytes imbalance; hypocalcemia (von Zumbusch subtype)
  • medications (lithium, iodine, penicillin, interferon-alpha, etc.)
  • pregnancy (impetigo herpetiformis)
  • phototherapy
  • vaccinations (BCG and H1N1)

Reference:

• Madanagobalane S. Secukinumab in Generalized Pustular Psoriasis. Indian Dermatol Online J. 2018 Nov-Dec;9(6):464-466