What Is Psoriasis?

Psoriasis is a common long-term (chronic) skin disease. Researchers think it develops from a combination of immune, genetic, and environmental factors. Psoriasis can start at any age. It's most common between ages 30 and 39 and also between ages 50 and 69.  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 doesn't spread from person to person.

About your symptoms

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 arthritis. Symptoms may come and go on their own. Stress, infection, and certain medicines may cause flare-ups. If symptoms bother you, many treatments are available to help ease symptoms. Discuss your treatment options with your healthcare provider.

Treatments for your skin

There are many types of medicines that can treat the affected skin lesions. Your healthcare provider may prescribe medicine such as:

  • Topical medicines. These are medicines that are put on the skin. These include moisturizers, steroids, types of vitamin D, medicines made from vitamin A (retinoids), and other non-steroid medicines. You can use them on a regular basis. 

  • Coal tar. This is a thick black liquid. You can put it on thick plaques.

  • Phototherapy. In some cases, your skin may be exposed to a special light in the provider's office. Or you can expose the psoriatic plaques to short periods (5 minutes) of natural sun as directed by your provider. Phototherapy can be helped with a type of medicine called psoralen.


Treatments by mouth or by shot

Internal treatments are taken by mouth (oral) or given by shot (injection). A number of new oral and injectable medicines can treat severe psoriasis. Your provider can tell you more about these treatments.

Online Medical Reviewer: L Renee Watson MSN RN
Online Medical Reviewer: Marianne Fraser MSN RN
Online Medical Reviewer: Michael Lehrer MD
Date Last Reviewed: 10/1/2021
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