Psoriasis is a chronic, noncontagious skin condition characterized by scaling and inflammation. The inflamed skin forms red, thickened areas with silvery scales. The condition is most commonly found on the scalp, elbows, forearms, knees, shins, ankles, and lower back. The inflammation may also affect the fingernails, toenails, soft tissues of the mouth, genitalia, and joints. The inflamed skin is usually asymptomatic, but may cause pain and discomfort by cracking. Psoriasis is rarely itchy.
Possible Regions of Psoriasis
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The exact cause of psoriasis has not been determined, but current theories suggest that it may be a disorder of the immune system. It appears that T-cells, a type of white blood cell that normally protects the body against infection and disease, trigger inflammation and excessive skin cell reproduction, which causes skin to shed too rapidly. Psoriasis is also believed to be associated with other cellular, biochemical, and metabolic defects.
Psoriasis flare-ups may be triggered by a variety of factors, including environment, certain medications, and stress.
There are five primary types of psoriasis:
Plaque psoriasis: This is the most common form. It is characterized by raised lesions which have a reddened base covered by silvery-white scales. The scales shed frequently and are very dry.
Guttate psoriasis: This type is most often triggered by bacterial infections (most commonly strep throat) and is most common in young adults and children. It is characterized by small, drop-like lesions on the trunk, limbs, and scalp. It may clear up by itself after a few weeks or months.
Pustular psoriasis: Blisters of non-infectious pus appear on the skin and may affect large or small areas of the body, most commonly fingers, palms and soles. This type of psoriasis is usually triggered by medications, infections, emotional stress, or certain chemicals. It may be triggered by abrupt withdrawal of systemic steroids.
Inverse psoriasis (also called flexural psoriasis): This is usually found in skin fold areas, such as the armpits, under the breasts, or folds of skin near the genitals or buttocks. It is more likely to be found in people who are overweight and may be exacerbated by friction or sweating in skin fold areas. The plaques are red, smooth, dry and large.
Erythrodermic psoriasis: This is the least common form of psoriasis and is characterized by widespread reddening and scaling of the skin as well as severe itching and skin discomfort. This form occur after a severe sunburn or use of certain medications.
Some people with psoriasis develop a condition called psoriatic arthritis. This occurs when the inflamed areas of the skin are accompanied by joint inflammation, most often in the hip, spine, knee, or elbow joints but also in the small joints of the hands and feet.
In some cases, psoriasis severely compromises quality of life. In addition to physical discomfort, people with psoriasis may develop emotional problems, such as depression or anxiety, and may experience social difficulties due to visible plaques. If you or a family member is suffering from psoriasis, seek out counseling, support groups, and services.
What are the risk factors for psoriasis?What are the symptoms of psoriasis?How is psoriasis diagnosed?What are the treatments for psoriasis?Are there screening tests for psoriasis?How can I reduce my risk of psoriasis?What questions should I ask my doctor?What is it like to live with psoriasis?Where can I get more information about psoriasis?
American Academy of Dermatologywebsite. Available at: http://www.skincarephysicians.com/ .
Gudjonsson JE, Elder JT. Psoriasis: epidemiology. Clin Dermatol . 2007;25(6):535-546.
National Psoriasis Foundationwebsite. Available at: http://www.psoriasis.org/home/ .
Last reviewed September 2012 by Purvee S. Shah, MD
Copyright © 2010 EBSCO Publishing All rights reserved.
Although most cases of psoriasis can be reliably diagnosed by simple physical examination, some cases can be difficult to diagnose, because the appearance can be similar to other skin conditions. Currently, there is no blood test that can conclusively diagnose psoriasis. A skin biopsy is the most specific test in the diagnosis of psoriasis.
Your doctor may do the following tests to determine whether or not you have psoriasis:
Physical examination —Your doctor will begin by carefully examining your skin, scalp, fingernails, and toenails for reddening or scaling skin that is characteristic of psoriasis. Small pits on the fingernails are also signs of psoriasis. Your doctor will also examine your joints for signs of psoriatic arthritis.
Skin biopsy —To confirm the diagnosis, your doctor may also take a small sample of skin (a biopsy) to test for psoriasis.
Severity of Psoriasis
Psoriasis affects people with varying degrees of severity. Seventy-five percent to 80% of people with psoriasis have what is considered mild psoriasis, while the remaining 20% to 25% have moderate to severe psoriasis. Treatment depends on the severity of the condition.
If you do have psoriasis, your doctor will assess the severity and grade it according to the following guidelines:
Mild psoriasis —If the psoriasis covers less than 2% of your body, it is considered mild. Usually, people with mild cases develop isolated patches of psoriasis on the knees, elbows, scalp, hands, and feet.
Moderate psoriasis —If the psoriasis covers 2% to 10% of your body, it is considered a moderate case. Psoriasis may appear on the arms, legs, torso, scalp, and other areas.
Severe psoriasis —When psoriasis covers more than 10% of your body, it is considered severe. Large areas of skin may be covered with psoriasis plaques or pustules, or widespread erythrodermic psoriasis can cause severe peeling of the skin. People with severe psoriasis are more likely to develop psoriatic arthritis.
As told to
Elissa Sonnenberg, MSEd
Terri is a 37-year-old mother of two who lives on Long Island. Before she first experienced psoriasis, she and her husband ran an electrical contracting business out of their home. Though it took her more than eight years to get the itchy, scaly skin condition under control, today she lives nearly symptom-free.
What was your first sign that something was wrong? What symptoms did you experience?
In 1991, after the birth of my first child, I started getting psoriasis. It started out as a dime-size, dry, patchy area on my elbow—white, scaly, itchy, flaky skin. When the dry flakes came off, it left a red rash. I also got small patches on my legs and stomach, but it was never really bad on my body. Then it got onto my scalp. It covered my scalp and started coming down my hairline. I also got it in my ear. It was really uncomfortable.
What was the diagnosis experience like?
I went to a dermatologist and he diagnosed me right away. It was kind of odd, because even though it's typically a hereditary condition, I'm the only person in my family that has psoriasis.
What was your initial and then longer-term reaction to the diagnosis?
Once something happens to me, I research it until I know everything I can about it. I joined the National Psoriasis Foundation and in their newsletters, I saw pictures of people that have it from head to toe. I felt like I was lucky. In the beginning, I had it in areas that were hidden. What really bothered me was when it went on my scalp. I didn't want to go out in public. I was very self-conscious. I didn't feel good about myself at all, but I never gave up trying different treatments.
How do you manage psoriasis?
My dermatologist started off by giving me topical steroid creams. They helped the patches on my body. One would go away on my elbow, but then another would pop up someplace else. But once it got on my scalp, during my second pregnancy, nothing helped. It never went away. During the pregnancy, I tried UVB light treatment. After a while I stopped going to dermatologists because nothing they did gave me any relief.
A lot of people in the National Psoriasis Foundation would write in with strange things that worked for them. I tried every single one of them—special shampoos, certain moisturizing products. You name it; I tried it. Nothing gave me relief, until I developed psoriatic arthritis in every joint in my body a couple of years ago. I couldn't walk, I couldn't move. I started an oral chemotherapy medication once a week, and later shots of Enbrel (etanercept, the only FDA-approved drug for psoriatic arthritis) twice a week. All of my psoriasis cleared up within 60 to 90 days of taking the shots. I was a normal person again.
Did you have to make any lifestyle or dietary changes in response to psoriasis?
When the psoriasis was bad, I didn't want to go out at all. But the doctor didn't tell me that I should cut anything out of my diet. I found out what vitamins, minerals, and herbs helped some people—I tried everything I heard about. I went out on my own and got herbal remedies. Nothing at all I found helped. Now I don't drink any alcohol because of the medications that I'm on.
Did you seek any type of emotional support?
The National Psoriasis Foundation has helped me so much. I subscribe to their newsletter and read about other people who have psoriasis and what they do that helps. It makes me feel better to see that I'm not alone.
Does psoriasis have any impact on your family?
I worked out of my home so it was very easy to manage at first. Nothing really changed; I just didn't like to go out. My kids went to a school near our home, so I only got out to take them to school and pick them up each day. I felt that everybody could see right through my hair. It totally killed my sex life, too.
What advice would you give to anyone living with psoriasis?
Don't give up. Subscribe to the National Psoriasis Foundation and you'll see that there are people just like you. Keep trying everything. I never thought I would find anything that would work for me, but I never gave up. I'm still looking into everything. Even though my psoriasis is taken care of, I still read up and see what works for other people.
Interviews were conducted in the past and may not reflect current standards and practices in medicine. Talk to your doctor to learn more about how this condition is diagnosed and managed today and what treatment approaches are right for you.
In general, outbreaks of psoriasis are difficult to prevent. However, avoiding or minimizing well-known triggers can help reduce the risk of an outbreak. These triggers include:
Stress: Maintaining emotional balance and avoiding stress are strongly recommended, as stress may be a trigger of psoriasis outbreaks. If you need support or assistance in reducing stress, you may want to try some of the following techniques:
Weather exposure: If you have had psoriasis, try to protect your skin at all times from cold, dry weather conditions, and minimize outdoor exposure during cold weather. Conversely, although, in mild to moderate doses UV light improves psoriasis, do not overexpose your skin to sunlight or develop a sunburn. Wear clothing that covers and protects your skin as much as possible, and hydrate the skin with baths and moisturizers after exposure. In addition to avoiding cold weather exposure, you can improve (or prevent) psoriasis symptoms by spending time in climates that are warm, humid, and sunny.
Skin injuries or trauma: Psoriasis outbreaks often occur in areas of the body that were previously injured. Prevention of cuts, burns, and other skin irritations may also help to prevent psoriasis flare-ups.
Infections: Although respiratory infections are often hard to avoid, doing so may help minimize your risk of a psoriasis flare-up. Your ability to fight off potential infection depends on maintaining of good immune system function, which you can enhance by getting plenty of rest and eating a healthful diet.
Medications: Certain medications like beta-blocker antihypertensives, antimalarials, lithium, and non-steroidal anti-inflammatory drugs (NSAIDs) may trigger a psoriasis flare-up. Be sure to tell your doctor that you have psoriasis when receiving a new medication.
American Academy of Dermatology
Address:P.O. Box 4014Schaumburg, IL 60168-4014
Description of services provided:On this website, you can find patient education information on psoriasis, as well as a related website (Psoriasisnet).
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Address:NIH1 AMS CircleBethesda, Maryland 20892-3675
Description of services provided:The National Institutes of Health site provides in-depth information on psoriasis, treatment, research, and more.
National Psoriasis Foundation
Address:6600 SW 92nd Ave., Suite 300Portland, OR 97223-7195
Description of services provided:This website provides online information on psoriasis, treatments, research, and news. It also offers free (print) educational materials, as well as answers to questions from patient educators.
Psoriasis Society of Canada
Address:PO Box 25015Halifax NS B3M 4H4
Description of services provided:To assist our affiliated chapters, and to represent their members' needs on a national level: assist those who have psoriasis by providing up-to-date information on treatment, programs and services; form support groups across Canada; increase awareness of psoriasis among health care professionals and the public; consult with government to assist with programs and services; encourage research programs to find the cause and cure for psoriasis.
Last reviewed October 2012 by Brian Randall
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
A risk factor is something that increases your likelihood of getting a disease or condition.
It is possible to develop psoriasis with or without the risk factors listed below. In fact, most cases of psoriasis are not associated with any of the risk factors listed below. However, the more risk factors you have, the greater your likelihood of developing psoriasis. If you have a number of risk factors, ask your doctor what you can do to reduce your risk.
Risk factors include:
There is a strong genetic component to psoriasis. In about one third of all cases, there is a family history of psoriasis.
Certain Medical Conditions
Medical conditions that are most likely to trigger psoriasis include:
Stress/emotional disorders: Stress, suppressed anger, anxiety, depression, or other emotional disorders often trigger psoriasis outbreaks.
Infection: Psoriasis frequently flares up after upper respiratory infections, such as tonsillitis, sinusitis, or strep throat.
Skin injuries: Psoriasis may develop at the site of a previous skin injury or mild abrasion, such as a cut, burn, or injection. This delayed development of psoriasis at these injured skin sites is known as the Köbner Phenomenon.
HIV/AIDS: Psoriasis may become particularly severe in people infected with HIV/AIDS.
Obesity: There is some evidence that obesity may exacerbate psoriasis.
Alcoholism: It is not entirely clear whether alcoholism is a risk factor for developing psoriasis or vice versa (due to the emotional burden of psoriasis). In any case, consuming excessive amounts of alcohol should be discouraged, especially during periods of psoriasis exacerbation.
Certain medications have been associated with triggering or exacerbating outbreaks of psoriasis. These include:
Plaque psoriasis first appears during 2 peak age ranges. The first peak occurs in persons aged 16-22 years, and the second occurs in persons aged 57-60 years. It is considered quite rare in infants, but may occur in children before the age of 10.
Psoriasis is more prevalent in fair-skinned people, particularly those who have a blood relative with psoriasis. It is less common in people with darker skin.
Psoriasis is often triggered by weather and climatic conditions. In general, people living in cold, dry climates are at much greater risk of developing psoriasis than people living in temperate or warm climates. In fact, warm, humid weather helps to heal psoriasis symptoms.
The purpose of screening is early diagnosis and treatment. Screening tests are usually administered to people without current symptoms, but who may be at high risk for certain diseases or conditions.
Screening Tests or Guidelines
At this time, there are no screening guidelines or tests for psoriasis.
There are several types of psoriasis. Each type of psoriasis has unique “signs.” Doctors look for signs during a physical exam so they can distinguish one type of psoriasis from another. Examples of signs include descriptions of the location and shape and pattern of the lesions. Symptoms are words that patients use to describe how their disease feels. Psoriasis is typically asymptomatic, but the affected skin may elicit discomfort due to shedding or fissuring. Most types of psoriasis are classically not itchy.
The following is a brief outline of each type of psoriasis and a description of the accompanying signs and symptoms.
Plaque psoriasis is the most common form. It is named for the “plaques,” or lesions, that are characteristic of this type of psoriasis. Plaques tend to be stable and slow growing, and they may remain unchanged for long periods of time.
Signs and symptoms include:
Guttate psoriasis is most often triggered by bacterial infections, such as streptococcus ( strep throat ), and is most common in childhood or young adulthood.
Most commonly found in skin fold areas of the body, such as the armpits, groin, under the breasts, and genital areas. This type of psoriasis is also known as flexural psoriasis.
This is the least common form of the disease. It can be triggered by severe sunburn, use of certain drugs, or abrupt withdrawal of oral steroids.
This form of psoriasis may be triggered by medication, emotional stress, infections, abrupt withdrawal of systemic steroids, or exposure to certain chemicals. It is a more rare form of psoriasis.
You have a unique medical history. Therefore, it is essential to talk with your doctor or doctor about your personal risk factors and/or experience with psoriasis. By talking openly and regularly with your doctor, you can take an active role in your care.
General Tips for Gathering Information
Here are some tips that will make it easier for you to talk to your doctor:
Specific Questions to Ask Your Doctor
About Your Risk of Developing Psoriasis
About Treatment Options
About Lifestyle Changes
About Your Outlook
Treatment of psoriasis is usually a series of steps, called the 1-2-3 approach, which entails:
Step 1—Topical: Sunlight or medication applied directly to the surface of the skin
Step 2—Phototherapy: Phototherapy (or “light treatment”) using ultraviolet light alone or in combination with medication
Step 3—Systemic: Medicines taken internally (usually oral medication) to treat psoriasis systemically
Your treatment will be based on several factors, including:
Often, the body will become resistant to certain types of treatment, and they will lose their effectiveness. When this happens, new treatment methods may be prescribed, and future treatments may be added as needed.
Treatment involves the following:
MedicationsOther treatmentsAlternative and complementary therapies
Surgical procedures are not a treatment option for psoriasis.
National Psoriasis Foundation website. Available at: http://www.psoriasis.org/home/ .
Azfar RS, Gelfand JM. Psoriasis and metabolic disease: epidemiology and pathophysiology. Curr Opin Rheumatol . 2008 Jul;20(4):416-22.
Behnam SM, Behnam SE, Koo JY. Alcohol as a risk factor for plaque-type psoriasis. Cutis . 2005 Sep;76(3):181-5.
Kirby B, Richards HL, Mason DL, Fortune DG, Main CJ, Griffiths CE. Alcohol consumption and psychological distress in patients with psoriasis. Br J Dermatol . 2008 Jan;158(1):138-40.
National Institute of Arthritis and Musculoskeletal and Skin Diseaseswebsite. Available at: http://www.niams.nih.gov/ .
American Academy of Dermatologywebsite. Available at: http://www.aad.org/default.htm/ .
American Academy of Dermatologywebsite. Available at: http://www.skincarephysicians.com/psoriasisnet/index.html .
American Academy of Dermatology web site. Available at: http://www.skincarephysicians.com/psoriasisnet/index.html.