What is it?

Psoriasis is a common, multi-system inflammatory disorder which is thought to have a complex immune-mediated aetiology.

Psoriasis can have varying clinical presentations ranging from localised large scaling plaques to a generalised rash of multiple small lesions. Pustular eruptions may occur.

It is a chronic, recurring disorder which is triggered by environmental factors such as infection, trauma, or drugs. It is not contagious.

Clinical presentation

Classical features are red, scaly patches of skin, with well-defined edges.

The overlying scale has a silvery-white appearance, but this is absent on the genitals due to the warm and moist environment. Genital psoriasis may present as salmon-red smooth, non-scaly patches most commonly on the penis or natal cleft.

Other signs to look for include:

  • large, flat patches or plaques on the extensor aspect of the elbows or knees
  • scaly tear-drop shaped spots on the trunk or buttocks (guttate psoriasis)
  • dry, flaky scalp or dandruff
  • nail changes such as pitting, ridging, onycholysis
Psoriasis 1
Psoriasis 2
Psoriasis 3
Psoriasis 4
1/4Psoriasis on the anus

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Psoriasis

Management

  • Patients should avoid any known triggers (such as certain soaps, synthetics).
  • Topical management is the mainstay of treatment, depending on the severity of the disease. Options include:
    • topical coal tar
    • salicylic acid (to remove scale)
    • steroids
  • Severe psoriasis should be referred to a dermatologist.