Psoriasis is a chronic skin condition in which red patches of various sizes develop on the skin, covered with dry, silvery scales. The name ‘Psoriasis’ comes from the Greek word meaning, 'itch'. The condition most often occurs on the elbows, knees, scalp, lower back, palms, and soles of the feet, but no area of the skin is exempt, including the genital area.

The disease may also affect the fingernails and toenails, and the soft tissues inside the mouth. About 15% of people with psoriasis have joint inflammation that produces arthritis symptoms. This condition is called psoriatic arthritis.


The exact cause of psoriasis is not fully understood, though it is thought to result from an abnormality in the functioning of white cells in the blood stream, triggering inflammation in the skin. Because of the inflammation, the skin sheds too rapidly, every three to four days.


Psoriasis usually begins with an itching sensation, followed by the appearance of small red bumps on the skin that develop into bigger scaly patches. As the scales accumulate, pink to deep red plaques with a white crust of silvery scales appear on the skin surface.


A wide range of treatments are available for psoriasis, but identifying which treatment is most effective can be difficult. Talk to your doctor or skin specialist if you feel a treatment isn't working, or you have uncomfortable side effects. Treatments fall into three categories:

  • Topical – creams and ointments
  • Phototherapy – the use of ultraviolet light
  • Systemic – oral and injected medications that work throughout the entire body

Often, different types of treatment are used in combination, and they may need to be reviewed regularly.