By Martha A. Simpson, D.O., M.B.A.
Assistant Professor of Family Medicine
Ohio University College of Osteopathic Medicine

PSORIASIS USUALLY MILD AND TREATABLE, BUT NEVER CURABLE

Question: I have had an itchy rash on my scalp since I was about 30. My doctor says I have psoriasis. Can you tell me about it? Will I always have it? What are some treatments?

Answer: Psoriasis is a chronic skin rash that commonly causes a white, scaly buildup on a red, raised base. These “plaques” or “lesions” typically become inflamed and covered by silvery white scale. Sometimes a sufferer has just a few lesions, but moderate to large areas of skin can be involved. Fortunately, for most people, psoriasis tends to be mild.

Psoriasis appears to be a genetic disease that runs in families and affects the skin and/or the joints. More than 4.5 million people in the United States suffer from one of the four types. The most common is called plaque psoriasis. Other types go by names such as guttate, featuring small dot-like lesions; pustular, characterized by weeping lesions and intense scaling; inverse, producing intense inflammation; and erythrodermic, creating intense shedding and redness of the skin.

The scalp, as in your case, is the single most common site for psoriasis. Other common sites are the knees, elbows and torso. But psoriasis can develop anywhere, including the nails, palms, soles, genitals and -- very rarely -- the face. Often the lesions are symmetrical and appear in “mirror image” on both the right and left sides of the body.

Psoriasis -- an immune-mediated problem -- is believed to be the result of too rapid skin cell growth. Normally, a skin cell takes about a month to go from the initial developmental stages to being shed from the surface. This cell turnover process is accelerated in psoriasis so the cells turn over every three to six days. This causes the skin cells to build up, causing the plaques and scaling. Part of this process may be the immune system stimulating T-cell activity by mistake, which in turn causes inflammation and increased cell turnover. Genetic links have been found for psoriasis, but not everyone with the psoriasis gene gets the disease.

Psoriasis is also known to flare up and improve on its own. Things that can bring on a psoriasis episode include emotional stress, injury to the skin, dry skin due to seasonal climate changes and certain medications. Some blood pressure medication -- beta-blockers in particular -- can make psoriasis flare up.

Psoriasis is not contagious, but many people are very self-conscious about their rash, so they shy away from contact with others. While psoriasis is treatable, it is not curable. Also, about a quarter of the people with the psoriasis rash also develop a specific form of arthritis.

There are many treatments for psoriasis, depending on the severity of the rash as well as the location. The treatments fall into one of three categories: topical, which refers to creams and lotions to use externally; phototherapy, which ranges from artificial light sources to carefully controlled sun exposure to the use of lasers; and systemic, which includes medications taken by pill or injection. The severity of the rash, its location and its response to previous therapies are all considered when the physician determines your treatment.

Current research is aimed at developing better drugs to treat the underlying immune-related cause and to understanding the genetics basis for this disease.

Family Medicine® is a weekly column. To submit questions, write to Martha A. Simpson, D.O., M.B.A., Ohio University College of Osteopathic Medicine, P.O. Box 110, Athens, Ohio 45701, or via email to readerquestions@familymedicinenews.org. Medical information in this column is provided as an educational service only. It does not replace the judgment of your personal physician, who should be relied on to diagnosis and recommend treatment for any medical conditions. Past columns are available online at www.familymedicinenews.org.