Types of Psoriasis
Anyone can have psoriasis. About 7.5 million people in the U.S. are affected, and it occurs equally in men and women. Psoriasis can occur at any age but is most often diagnosed between the ages of 15 to 25. It is more frequent in Caucasians.
Psoriasis commonly occurs on the scalp, which may cause fine, dry, scaly skin or heavily crusted plaque areas. This plaque may flake or peel off in clumps. Scalp psoriasis may resemble seborrheic dermatitis, but in that condition the scales are greasy and not dry.
Quick GuideTypes of Psoriasis: Medical Pictures and Treatments
What is scalp psoriasis? When can scalp psoriasis begin?
Psoriasis is an inflammatory disease of the skin that is estimated to affect about 2.2% of the adult population. In children, the onset of psoriasis can be before the age of one year but peaks around 5-8 years. Psoriasis produces scaly, itching bumps on the skin. Some people may have a genetic predisposition to psoriasis. The genes affected seem to be involved with control of the immune system. Psoriasis appears as red scaling, slightly raised bumps (papules) that merge to form plaques. Psoriasis classically appears on the elbows and knees, but it can affect any part of the skin. The scalp is also characteristically affected in many people. Like psoriasis anywhere on the body, scalp plaques produce excess scale and can itch. Severe disease can cause a loss of scalp hair, which usually will return if the disease can be controlled. Scalp psoriasis somewhat difficult to treat when the scalp is covered with hair sufficient to act a barrier to the application of topical medications.
Picture of scalp psoriasis. Source: iStock.com.
What are causes and risk factors of scalp psoriasis?
It is generally accepted that scalp psoriasis, like all psoriasis, is related to genetic defects that affect certain parts of the immune system. There are undoubtedly environmental risk factors that trigger its initial development in genetically predisposed individuals. The notion that "emotional stress" plays a causal role or at least exacerbates psoriasis has been difficult to prove. There is no question, however, that psoriasis of the scalp can be an extremely stressful experience.
What are scalp psoriasis symptoms and signs? Can scalp psoriasis cause hair loss?
Psoriasis appears as a small bump, a papule, surmounted by scale. When these papules coalesce, a plaque is formed that is often covered by thick layers of horny scale. When this scale is shed, it appears as dandruff, which can be quite unsightly. Scratching these plaques, either because of itching or because of the impulse to remove it, is a very poor idea because of what is called the Koebner phenomenon (also known as the Koebner response or isomorphic response). This may cause psoriasis to develop in areas of inflammation and trauma. Scratching off the scale will only make things worse. Although most patients do not note hair loss, there can be extensive alopecia hair loss (alopecia) in severe cases.
Medically Reviewed by a Doctor on 12/8/2016