Under normal circumstances, the cells of the outer layer of the skin are constantly being shed and replaced by new cells. In psoriasis however, (for reaosns that are still unknown) the production of new skin cells is sped up - these excess cells accumulating in thick, reddish, flaky patches (plaques) on the surface of the skin, which then become cracked and sore. The outer skin cells grow and multiply about 10 times more quickly than required - turning over every 4-5 days instead of every 28 days.

Milder forms of psoriasis may only produce a few occassional patches, while in severe cases, sufferers are constantly bothered by lesions one one or another art of their bodies. Nevertheless, psoriasis is a recurrent disease that erups from time to time, often starting in young adulthod.

Psoriasis usually occurs on areas exposed to friction, irritation or infection i.e. elbows and knees - although it has been known to affect the scalp, where it is often confused with seborrhoeic dermatitis.

At one stage it was thought that psoriasis was just skin-deep, however it is now known that a severe case can affect the entire body.
e.g. Erythrodermic (inflammatory) psoriasis may diminish the body's heat regulation, dilate blood vessels in the skin and cause heat loss and cold sensitivity.
General erythroderma is potentially life threatening as is causes peeling and redness of the whole body resulting in moisture loss and high fever.

Treatment:

Treatment usually starts with the family doctor who refers the patient to a dermatologist if necessary.
The scaly patches can often be made to disappear through treatment with an ultraviolet lamp or through the use of a variety of ointments, creams and gels; special shampoos and bath additives may also prove effective.
 

• Topical steroids may also help, but can result in side-effects if overused.
• Methotrexate (anti-cancer drug) slows down the rate at which cells divide and is helpful in severe cases.
• PUVA therapy, in which a combination of ultraviolet light and Psoralen is used may also help.
• Etretinate is often prescibed for severe cases of psoriasis. (Women should avoid pregnancy for at least 1 year after discontinuation, since it may cause foetal abnormalities)
• Medicated ointments such as salicyclic acid, steroid (cortisone) and tar products often work very well.
• Cyclosporine is also proving effective, but needs to be taken with care because of possible kidney damage.
• Dithsarol (tar alternative) is useful when treating psoriasis, however, it may be difficult to manage as it does harm normal, unaffected skin.
• The essential oil of Lavender can be used in the bath , as well as applied to the skin in a lotion or oil.
• Relaxation techniques may also help, as stress is considered to be a factor in provoking flare-ups.
   

Back to A-Z Listing of Diseases and Disorders