The most common type of psoriasis is called plaque psoriasis. It causes a thick, patchy, red rash with silvery, white scales. It can appear anywhere but most often occurs on the scalp, elbows, knees, and lower back. The condition is not contagious, and it's fairly common, affecting 2% to 3% of Americans. Psoriasis is more common in adults than children.
Psoriasis typically starts as a few red bumps. These may become larger and thicker, eventually developing scales. The patches may join together and cover large areas of the body. The rash can be itchy and uncomfortable, and it may bleed easily if rubbed or picked.
Up to half of people with skin plaques have psoriasis of the nails as well. This makes the nails look yellowish-red. The nails may also crumble, become pitted, or develop grooved lines. Nearly everyone with psoriasis of the nails also has psoriasis somewhere on the skin.
About 15% of people with psoriasis develop psoriatic arthritis, a painful and sometimes disabling inflammation of the joints. Psoriatic arthritis can occur at any age but is most common between the ages of 30 and 50.
What Causes Psoriasis?
The exact cause of psoriasis is unknown, but experts believe that the immune system, genes, and environmental factors play central roles. Normally, old skin cells are replaced with new ones every four weeks. In people with psoriasis, the immune system triggers inflammation, causing new cells to move to the surface every three or four days. The resulting buildup forms the rash. Psoriasis cannot be passed from person to person, but it does tend to run in families.
People with psoriasis may find their condition flares up at certain times. Common triggers include:
Skin injury or infection
Smoking or drinking alcohol
The Stigma of Psoriasis
For some people, psoriasis can affect their emotions and self-image. A stubborn, unsightly rash can transform a confident, outgoing person into a wallflower. People may avoid dates, social events, or job interviews. All of this can increase the risk of depression and anxiety, which can worsen the symptoms of psoriasis.
A doctor can usually diagnose psoriasis by examining your skin, scalp, and nails. A biopsy can be done to confirm the diagnosis. If you have swelling and pain in your joints, your doctor may also order blood tests and X-rays to check for arthritis. Psoriasis cannot be cured, but treatments can relieve symptoms and control the condition.
People with mild to moderate psoriasis may benefit from topical treatments -- creams or ointments that reduce inflammation, itching, and the rate of skin cell growth. These include steroid topicals, moisturizers, salicylic acid, anthralin, retinoids, calcipotriene, (a form of vitamin D), and coal tar. Tar shampoos are helpful for psoriasis of the scalp.
For moderate to severe psoriasis, UVB phototherapy is an effective treatment option. This strategy treats the skin with controlled exposure to ultraviolet light. It can be done at a doctor's office or at home using a special light device. PUVA is a form of phototherapy that combines a medicine called psoralen with UVA light. PUVA (seen here) and UVB phototherapy can help clear up psoriasis but may have troubling side effects.
Treatment: Laser Therapy
A new twist on phototherapy is the use of lasers, which emit highly focused beams of light. This lets doctors aim the treatment at affected areas without exposing healthy skin. Laser therapy may have fewer side effects and a smaller risk of skin cancer compared to traditional phototherapy. It also appears to deliver results with fewer treatments.
Treatment: Oral Medications
Oral medications target the overactive immune system, not just the symptoms of psoriasis. These drugs are recommended only when psoriasis hasn't responded to other therapies. Options include methotrexate and cyclosporine. Both have serious side effects, so patients must be monitored carefully. Certain oral retinoids can also be used to treat severe psoriasis.
Biologics are a relatively new alternative for people with psoriasis. These are drugs made from living cells. Like some older psoriasis medications, they alter the activity of the immune system. Biologics are given by injection or intravenous infusion. Because they suppress the immune system, they can make you more vulnerable to serious infections.
Natural Remedies for Psoriasis
Soaking up the sun is a tried-and-true remedy for psoriasis. As many as 80% of people who get regular sun exposure say their symptoms improve. The trick is not to overdo it -- a sunburn actually makes psoriasis worse. Other natural alternatives include aloe, tea tree oil, and oatmeal baths to soothe itchy skin. Although alcohol has been linked to psoriasis, experts are skeptical about special diets that claim to treat psoriasis. There's no convincing evidence that they work.
For decades, people have claimed that visiting the Dead Sea in Israel is a powerful treatment for psoriasis. The sun and water, which is 10 times saltier than the ocean, are believed to be a healing combination. It may sound like a myth, but scientific evidence suggests this form of climatotherapy works. In studies, 80% to 90% of patients improved after visiting the Dead Sea. Almost half saw their rash disappear for the next several months.
Stress tends to worsen psoriasis, so relaxation techniques may help control flare-ups. Anything that helps you relax, whether it's yoga, deep breathing, or a long walk, may help ease your symptoms.
There may be days when you feel like hiding at home. But it's a mistake to deprive yourself of the friendships and activities you enjoy. Isolation can lead to stress and depression, which tend to make symptoms worse. Experts recommend staying connected to the people you trust. You may also want to look into a support group through the National Psoriasis Foundation.
American Academy of Dermatology web site.
American Academy of Dermatology's PsoriasisNet web site.
American College of Rheumatology web site.
International Eczema-Psoriasis Foundation web site.
National Institute of Arthritis and Musculoskeletal and Skin Diseases web site.
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional medical advice, diagnosis or treatment and should not be relied on to make decisions about your health. Never ignore professional medical advice in seeking treatment because of something you have read on the WebMD Site. If you think you may have a medical emergency, immediately call your doctor or dial 911.