Defining Psoriasis

Psoriasis is a chronic scaling skin. It may range from just a few spots anywhere on the body to large areas of involvement. It is not contagious or spread able from one part of the body to another or from one person to another. There is no blood test to diagnose psoriasis. The diagnosis is made by observation and examination of the skin. Sometimes microscopic examination of the skin (biopsy) is helpful where the changes are not typical or characteristic. The exact cause of psoriasis is unknown, but hereditary and genetic factors are important. Psoriasis runs in families. This does not mean, however, that every child of a parent with psoriasis will develop psoriasis, but it is common that somewhere down the line psoriasis will appear in families. Psoriasis is not caused by allergies, infections, dietary deficiencies or excesses, or nervous tension.