Disorders of the Skin - Psoriasis

Psoriasis is a noncontagious chronic condition in which the skin on various parts of the body is marked by bright red patches covered with silvery scales. The areas most often affected are the knees, elbows, scalp, and trunk, and less frequently, the areas under the arms and around the genitals.

The specific cause of psoriasis has not yet been discovered, but it is thought to be an inherited abnormality in which the formation of new skin cells is too rapid and disorderly. In its mild form, psoriasis responds well to a variety of long-term treatments. When it is acute, the entire skin surface may be painfully red, and large sections of it may scale off. In such cases, prompt hospitalization and intensive care are recommended.

Conditions That Can Bring On an Outbreak

The onset or aggravation of psoriasis can be triggered by some of the following factors:

1. • bruises, burns, scratches, and overexposure to the sun
2. • sudden drops in temperature—a mild, stable climate is most beneficial
3. • sudden illness from another source, or unusual physical or emotional stress
4. • infections of the upper respiratory tract, especially bacterial throat infections and the medicines used to cure them

Treatment

Although there is no specific cure for psoriasis, these are some of the recommended treatments:

1. • controlled exposure to sunlight or an ultraviolet lamp
2. • creams or lotions of crude coal tar or tar distillates, used alone or in combination with ultraviolet light
3. • psoralen and ultraviolet light (PUVA), a combined systemic-external therapy in which a psoralen drug is taken orally before exposure to ultraviolet light
4. • systemic drugs, such as metho-trexate, which can be taken orally
5. • steroid hormone medications applied to the skin surface under dressings