Psoriasis is a chronic skin disease. Psoriasis can begin at any age. It is most common between ages 30 and 39 and also between ages 50 and 69. Psoriasis affects nearly equal numbers of men and women. In people with this disease, the skin grows too fast. Dead skin cells build up on the skin’s surface to form inflamed, thick, silvery scales called plaques. Sometimes people form many small lesions that can hurt or have pus in them. Psoriasis does not spread from person to person.
Psoriasis plaques tend to form on the elbows, knees, scalp, navel, arms, legs, and the penis or vulva. They can be unsightly, painful, and itchy. Plaques on the joints can limit movement. On the fingernails or toenails, psoriasis can cause pitting, a change in nail color, and a change in nail shape. In some cases, psoriasis also causes symptoms that are like arthritis. Symptoms may come and go on their own. Factors such as stress, infection, and certain medications may cause flare-ups. If symptoms bother you, know that many effective medical treatments exist that can help relieve symptoms for most people with psoriasis. Discuss your treatment options with your health care provider.
There are many types of external medical treatments that are used to treat the affected skin lesions. Your health care provider may prescribe one of many types of topical medications. These include strong topical steroids or steroid-sparing agents. You apply them to your skin on a regular basis. Coal tar (a thick black liquid) may be applied to thick plaques. In some cases, the skin may be exposed to a special light in the health care provider's office. Or, you can expose the psoriatic plaques to short periods (5 minutes) of natural sun as directed by your health care provider. This method is called phototherapy. It can be enhanced with the use of psoralen (a type of medication).
Internal treatments are taken orally (by mouth) or given by injection. There are a number of oral medications for more severe psoriasis. Your health care provider can tell you more about these treatments.