Psoriasis

Psoriasis is a chronic, inflammatory skin disease. Knees, elbows, scalp, trunk, and nails are the most commonly affected areas. There are several types of Psoriasis.
  • Plaque - inflamed patches of skin topped with silvery, white scales (most common type)
  • Guttate - small dot-like lesions
  • Pustular - weeping lesions and intense scaling
  • Erythrodermic - intense sloughing and inflammation of the skin

Causes

The cause of Psoriasis is unclear. It may be related to a defect in the immune system that causes the immune system to send signals that result in an overgrowth of skin cells. Because the cells grow faster than they can be shed, they ‘pile up' on the skin's surface. The excess skin cells are thought to cause the silvery white scales that are characteristic of plaque-type Psoriasis.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.
  • Sex: Female
  • Family history of psoriasis
  • Rheumatoid arthritis
  • Stress
  • Cold climates
  • Suppression of the immune system, including AIDS
  • Bacterial infections
  • Certain medications, including oral steroids, beta blockers, and lithium

Symptoms

  • Rough, dry, thick areas of the skin
  • Silvery white scales
  • Patches of red, raised skin
  • Pitted or dented fingernails and/or toenails
  • Arthritis or joint pain

Diagnosis

The doctor will ask about your symptoms and medical history, and perform a physical exam. Your skin and nails will be examined. There are no special blood tests or diagnostic procedures for Psoriasis. Sometimes a skin biopsy will be done to confirm the diagnosis.

Treatment

Treatment is based on:
  • The severity of the disease
  • The extent and location of the areas involved
  • Responsiveness to the treatment
Topical treatment
Many patients respond very well to treatments applied directly to the skin. Topical treatments include cortisone creams, synthetic forms of vitamin D and retinoids, coal tar preparations, bath solutions, and moisturizers.
Photo (light) therapy
Daily, short, nonburning exposure to sunlight clears or improves psoriasis in many people. Sunlight is often included among initial treatments. A more controlled form of artificial light treatment is often used in mild psoriasis (UVB phototherapy). More severe psoriasis can be treated with ultraviolet A (UVA light) and psoralen. Psoralen is an oral or topical medication that makes the body more sensitive to light. This treatment is known as PUVA.
Phototherapy can be very effective in controlling psoriasis but it requires frequent treatments. It may cause side effects such as nausea, headache, fatigue, burning, and itching. Both UVB and PUVA may increase the person's risk for squamous cell and melanoma skin cancers.
Systemic Treatment
For more severe types of psoriasis, doctors may prescribe a number of medications, including:
  • Methotrexate - should not be taken by pregnant women, women planning to become pregnant, or by their male partners.
  • Cyclosporine - suppresses the immune system to slow the turnover of skin cells.
  • Hydroxyurea - less toxic than methotrexate or cyclosporine.
  • Retinoids - compounds with vitamin A-like properties, may be prescribed for severe cases of psoriasis that don't respond to other treatments. Because retinoids can cause birth defects, women must diligently protect themselves from pregnancy.

Prevention

Although Psoriasis cannot be prevented, people with a family history of Psoriasis should try and prevent physical trauma to the skin, infections, extremes of outdoor temperature, and stress. If certain food appears to make the psoriasis worse, those foods should be avoided.