What Is Psoriasis? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Psoriasis is an autoimmune disease?that causes plaques, which are itchy or sore patches of thick, dry, discolored skin.

While any part of your body can be affected, psoriasis plaques most often develop on the elbows, knees,?scalp, back, palms, and feet.

Like other autoinflammatory diseases, psoriasis occurs when your immune system — which normally attacks infectious germs — begins to attack healthy cells instead.

6 Easy Snacks for Your Anti-Psoriasis Diet

These anti-inflammatory treats will satisfy your cravings, boost your overall health, and possibly reduce your risk of a psoriasis flare.
6 Easy Snacks for Your Anti-Psoriasis Diet

Signs and Symptoms of Psoriasis

Psoriasis plaques can range from a few spots of?dandruff-like scaling to major eruptions that cover large areas. The disease’s symptoms and appearance vary according to the type and severity of psoriasis.

Some common signs and symptoms include:

  • Discolored patches — classically, they’re red on fair skin and purple on dark skin — or raised plaques of skin that are covered with scales
  • Dry or cracked skin that bleeds
  • Burning, itching, or soreness near the affected areas
  • Pitted or thickened fingernails or toenails
  • Swollen joints (1)

Learn More About Psoriasis Symptoms

Causes and Risk Factors of Psoriasis

Psoriasis, in general, is a genetic condition passed down through families. “It’s likely that multiple genes need to be affected to allow psoriasis to occur and that it’s frequently triggered by an external event, such as an infection,” says?James W. Swan, MD, a dermatologist who specializes in psoriasis at Loyola Medicine in?Maywood, Illinois.

Certain risk factors, such as a family history or being obese, may increase your odds of developing psoriasis.

At least 10 percent of people inherit genes that could lead to psoriasis, but only 3 percent or less actually develop the disease. (2) For this reason, it is believed that the disease is caused by a combination of genetics and external factors or triggers.

A psoriasis outbreak may be provoked by:

Stress

Stress?is a major trigger for some people with psoriasis, either causing psoriasis to flare up for the first time or to make it worse after you’ve been diagnosed. (3)

“Psoriasis is very stress-dependent. It flares very easily when patients are under stress, and it tends to improve when they’re relaxed,” says Vesna?Petronic-Rosic, MD, a visiting professor at the University of Illinois Chicago and the director of dermatopathology at John H. Stroger, Jr. Hospital of Cook County in Chicago. Stress management techniques, such as exercise, yoga, and meditation, may help manage psoriasis symptoms.

Cold Weather?

A trip to the Caribbean might be a good idea during the winter months if you have psoriasis and live in a cold climate. That’s?because the sun’s ultraviolet light turns off the skin’s immune system, which is overactive in people with psoriasis. Check with your dermatologist before traveling for sun safety skin tips and limit your daily exposure to no more than 10 minutes of direct sunlight.

Dry Skin?

Anything that injures the skin can cause a psoriasis flare, including excessively dry skin.

The solution:?Keep your skin moisturized. If you’re allergic to the fragrances in moisturizers, use a product that’s fragrance-free to avoid a rash.

Vaccinations?

As with dry skin, puncturing the skin during a vaccination may cause a psoriasis flare, but that’s no reason to skip a needed shot. (4)

One thing to keep in mind: If you’re on a potent psoriasis medication that suppresses your immune system (such as a biologic treatment), you shouldn’t take a live vaccine. Your body may not be able to fight off a live virus because of the medication you’re taking. In that case, ask your doctor for a vaccine that contains a deactivated virus.

Beta-Blockers and?Lithium?

Beta-blockers to treat?high blood pressure?and?lithium?for a mental disorder can make psoriasis worse. (5,6)

If you have high blood pressure, your doctor may be able to switch your medication to another drug that won’t affect the psoriasis. If you’re taking lithium, your dermatologist may consider having you try light?therapy or a topical treatment for psoriasis.

Upper Respiratory Infections?

Colds?and other infections, especially strep throat, activate the immune system and can cause psoriasis to flare. (7) If you have psoriasis and develop a sore throat, get it treated and be sure to have a culture taken to check for strep. Long-term?antibiotics?may be an option for someone who has psoriasis and frequent sore throats.

Smoking?

There’s some evidence that smoking can make psoriasis worse.?According to a study, smokers have almost double the risk of developing psoriasis compared with people who’ve never smoked. (8) In a smaller?study that looked at twins, heavy smokers were more than twice as likely to have psoriasis. (9)

Diet?

Studies haven’t shown any beneficial effects of taking nutritional supplements for psoriasis, but avoiding certain foods may reduce inflammation and help with psoriasis. Additionally, studies have shown that many people with psoriasis may also have a?gluten?sensitivity, and eating a?gluten-free diet?can help reduce?psoriasis symptoms. (10)

It’s also best to eat nightshade vegetables — including eggplant, tomato, white potato, and peppers — in smaller quantities; they contain a chemical known to cause inflammation. In general, if you find that a certain food makes the psoriasis worse, try to avoid it.

Alcohol?

For some people with psoriasis, having more than one or two drinks a day has been shown to cause psoriasis flares, but the association is not a strong one. Flares from alcohol use could also be linked to psychological stress.

Learn More About Psoriasis Causes

Types of Psoriasis

There are five types of psoriasis, yet people most often have only one type of psoriasis at a time. Each type has its own set of symptoms.

Plaque Psoriasis

Also called psoriasis?vulgaris,?plaque psoriasis?is the most common form of the skin disease. It appears as raised, discolored plaques covered with a scaly buildup?of dead skin cells, or scales. The itchy, sometimes painful plaques can crack and bleed, and commonly affect the scalp, knees, elbows, back, hands, and feet.

Guttate?Psoriasis

Often beginning in childhood or young adulthood,?guttate?psoriasis?is the second most common type of psoriasis. Nearly 10 percent of people who get psoriasis develop?guttate?psoriasis. Guttate psoriasis is the type of psoriasis most closely linked to a recent strep infection. If you develop guttate psoriasis, you will also likely be tested for strep bacteria.

Inverse Psoriasis

Also known as?intertriginous?psoriasis,?inverse psoriasis?causes red or otherwise discolored lesions in skin folds of the body that may look smooth and shiny. Each lesion can occur on the genitals or in areas near the genitals, like the upper thighs and groin. It’s common for people with inverse psoriasis to have another type of psoriasis somewhere else on their body at the same time.

Pustular?Psoriasis

This causes white blisters of pus that surround red or otherwise discolored skin, often on the hands or feet. The pus consists of white blood cells. When pus-filled bumps cover the body, you may have bright-red skin and feel ill or exhausted, and have a fever, chills, severe itching, rapid pulse, loss of appetite, or muscle weakness.

Erythrodermic Psoriasis

This is a dangerous and rare form of the skin disease characterized by a widespread, fiery redness or other discoloration and exfoliation of the skin that causes severe itching and pain.?Erythrodermic psoriasis?occurs once or more in 3 percent of people with psoriasis.

Learn More About the Types of Psoriasis

How Is Psoriasis Diagnosed?

There aren’t any special tests to help doctors diagnose psoriasis. Typically, a dermatologist will examine your skin and ask about your family history.

You’ll likely be given a diagnosis based on this physical exam.

In some situations, doctors will remove a small sample of the skin and examine it under a microscope. This might allow them to get a better look at the affected area and make a more accurate diagnosis. (11)

Duration of Psoriasis

Psoriasis is considered a chronic, lifelong condition. There currently isn’t a cure, and this skin disorder can worsen or improve.

For some, psoriasis can clear up for months or even years at a time. This is known as remission.

Others experience psoriasis flares in cyclical patterns. For instance, the disease may get better in the summer and worsen in the winter. (12) There are treatments that can keep your skin clear or nearly clear.

Treatment and Medication Options for Psoriasis

While psoriasis cannot be cured, there are effective options for treating it. Talk to your doctor about the benefits, risks, and side effects of any therapies you use.

Medication

Some medication to treat psoriasis includes:

Light Therapy

Light therapy, such as UVB phototherapy, involves exposing your skin to controlled amounts of natural or artificial ultraviolet light to help reduce symptoms of psoriasis. You may receive this treatment alone or along with other medication. (1)

Learn More About Psoriasis Treatment

Prevention of Psoriasis

There’s no way to prevent psoriasis, but there are things you can do to improve your symptoms and help lessen the number of flare-ups you experience. (13)

Some ways to reduce your risk of a psoriasis outbreak include:

  • Take daily baths
  • Keep skin moisturized
  • Avoid triggers if you can
  • Get a small amount of sunlight each day (1)

Complications of Psoriasis

Having psoriasis can increase your risk for developing a number of health conditions, including:

  • High blood pressure
  • Obesity
  • High cholesterol
  • Diabetes
  • Cardiovascular disease
  • Osteoporosis
  • Liver disease
  • Kidney disease
  • Cancer
  • Uveitis (an eye disease)
  • Crohn’s disease
  • Depression (14)

“Over the past few years, we've seen that maybe psoriasis plays a more integral part in metabolic syndrome, a collection of symptoms that can lead to diabetes and heart disease,” says?Erin Boh, MD, chairman and a professor of dermatology at the Tulane University School of Medicine in New Orleans.

It is?estimated that up to 30 percent of people?with psoriasis will also develop?psoriatic arthritis, an autoimmune disease that affects the joints. Psoriasis occurs before joint disease in 85 percent of psoriatic arthritis patients. (15)

The risks for psoriasis-related complications are greater the younger a patient is when diagnosed and the more severe the psoriasis. (16) Anyone with psoriasis should be aware that they are at risk for comorbid conditions and should monitor their overall health accordingly.

Learn More About Psoriasis Complications

Research and Statistics: Who Has Psoriasis?

About 7.5 million people in the United States have psoriasis. Most are white, but the skin disease also affects Black, Latino, and Asian Americans as well as Native Americans and Pacific Islanders. (17)

The disease occurs about equally among men and women. It is more common in adults, and you are at a greater risk if someone in your family has it. (18) A?study concluded that “interactions between particular genes as well as genetic and environmental factors play an important role” in the disease’s development. (19)

People with psoriasis generally see their first symptoms between ages 15 and 30, although developing the disease between 50 and 60 years of age is also common. (20)

“The biggest factor for determining prognosis is the amount of disease someone has,” says?Michael P.?Heffernan, MD, a dermatologist at the San Luis Dermatology & Laser Clinic in San Luis?Obispo, California.

Related Conditions

Many conditions are closely related to, and sometimes mistaken for, psoriasis.

Psoriasis and eczema may be tricky to tell apart.

If psoriasis affects your scalp, it might be hard to determine if it’s dandruff or psoriasis.

Other skin conditions like ringworm and pityriasis rosea are occasionally confused with psoriasis.

Is It Psoriasis or Eczema?

Like psoriasis, eczema is a very itchy skin condition. In fact, eczema usually results in a more intense itch than psoriasis. Scratching causes inflammation of the skin, leading to a worsening of the eczema. Scratching can also cause a secondary bacterial infection.

Eczema is not a specific disease, but rather a term referring to a group of rash-like conditions. The most common type of eczema is caused by a reaction to irritants, like detergents, soaps, or household cleansers.

Eczema often shows up on the back of the knees or the inside of the elbows.

Eczema?can affect anyone and affects children more than psoriasis does. (21)

Is It Scalp Psoriasis or Dandruff?

More than half of all psoriasis patients have scalp psoriasis. (22) Itchy plaques can extend beyond the hairline onto the forehead, neck, and around the ears.

“Most people with scalp psoriasis have it on other parts of their body as well,” says?Dina D. Strachan, MD, a dermatologist and assistant clinical professor of dermatology at NYU Langone Health in New York City.

Scalp psoriasis is sometimes confused with seborrheic dermatitis, or?dandruff. According to Dr. Strachan, dandruff — which causes a flaky, itchy scalp without signs of inflammation — tends to itch more than scalp psoriasis. “It has a greasy-appearing yellow scale,” Strachan says. “In contrast, psoriasis — whether it's on your scalp or any other body part — tends to have a thick, silvery scale."

Learn More About Whether That Rash Is Psoriasis, Eczema, or Something Else

Learn More About Scalp Psoriasis

BIPOC and Psoriasis

Psoriasis is less common in BIPOC (Black, Indigenous, and People of Color) populations compared with white ones, but it may be more severe and more challenging to diagnose.

According to research, psoriasis affects about 3.6 percent of Caucasians, as well 1.9 percent of African Americans and 1.6 percent of Hispanic Americans.

The appearance of psoriasis can differ depending on race and ethnicity. Psoriasis tends to be red or pink with silvery-white scale in white patients, while a Hispanic person is more likely to have salmon-colored psoriasis and silvery-white scale. In Black Americans, psoriasis often looks violet and the scale gray, or can be a deep brown and hard to see on people with very dark skin.

Psoriasis can be more severe for people of color than white people. A study found that Asians with psoriasis had the highest percentage of body surface area affected (41 percent), while Caucasians had the lowest (28 percent).

People of color who have psoriasis are less likely to get appropriate and timely treatment than their white counterparts. A study found that Black, Asian, and Native Americans are 40 percent less likely to see a dermatologist for their psoriasis than non-Hispanic white Americans, regardless of their health insurance or socioeconomic status.

One reason more people of color with psoriasis are not receiving high-quality treatment may be systemic racism in the medical field and the health disparities it causes. An analysis of dermatology textbooks showed that the number of images of skin of color ranged from 4 to 18 percent, with many textbooks showing zero images of skin of color with psoriasis.

Common Questions & Answers

Who is most at risk for psoriasis?
Psoriasis is a genetic condition that can be passed down through families. It occurs about equally among men and women, and symptoms usually develop between age 15 and 35.
What types of psoriasis are there?
There are several types of psoriasis. Psoriasis types include plaque psoriasis, guttate psoriasis, inverse psoriasis, pustular psoriasis, and erythrodermic psoriasis.
Is psoriasis associated with other health conditions?
Yes. Psoriasis is associated with health conditions such as high blood pressure, high cholesterol, diabetes, and depression.
Do all people with psoriasis also have psoriatic arthritis?
No. It is estimated that up to 30 percent of people with psoriasis will develop psoriatic arthritis. Psoriasis occurs before joint disease in 85 percent of people with psoriatic arthritis.
What can trigger a psoriasis flare-up?
Psoriasis flares may be triggered by stress, cold weather, dry skin, upper respiratory infections, and smoking. Avoiding certain foods and alcohol may help with psoriasis.

Resources We Trust

Editorial Sources and Fact-Checking

Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.

Resources

  1. Psoriasis: Symptoms and Causes.?Mayo Clinic. October 8, 2022.
  2. Causes and Triggers.?National Psoriasis Foundation. December 21, 2022.
  3. Basavaraj KH, Navya MA, Rashmi R. Stress and Quality of Life in Psoriasis: An Update.?International Journal of Dermatology. July 2011.
  4. Gunes AT, Fetil E, Akarsu S, et al. Possible Triggering Effect of Influenza Vaccination on Psoriasis.?Journal of Immunology Research.?August 25, 2015.
  5. Kim GK, Del Rosso JQ. Drug-Provoked Psoriasis: Is It Drug Induced or Drug Aggravated??The Journal of Clinical and Aesthetic Dermatology. January 2010.
  6. Jafferany M. Lithium and Psoriasis: What Primary Care and Family Physicians Should Know.?The Primary Care Companion to the Journal of Clinical Psychiatry. 2008.
  7. Sigurdardottir SL, Thorleifsdottir RH, Valdimarsson H, Johnston A. The Association of Sore Throat and Psoriasis Might Be Explained by Histologically Distinctive Tonsils and Increased Expression of Skin-Homing Molecules by Tonsil T Cells.?Clinical & Experimental Immunology. October 2013.
  8. Li W, Han J, Choi HK, Qureshi AA. Smoking and Risk of Incident Psoriasis Among Women and Men in the United States: A Combined Analysis.?American Journal of Epidemiology.?March 1, 2012.
  9. L?nnberg AS, Skov L, Skytthe A, et al. Smoking and Risk for Psoriasis: A Population-Based Twin Study.?International Journal of Dermatology. February 2016.
  10. Bhatia BK, Millsop JW, Debbaneh M, et al. Diet and Psoriasis, Part II: Celiac Disease and Role of a Gluten-Free Diet.?Journal of the American Academy of Dermatology. August 2014.
  11. About Psoriasis.?National Psoriasis Foundation. February 22, 2023.
  12. Patient Education: Psoriasis (Beyond the Basics).?UpToDate. July 28, 2022.
  13. Prevention.?Stanford Medicine Health Care.
  14. Related Conditions of Psoriasis.?National Psoriasis Foundation. October 8, 2020.
  15. About Psoriatic Arthritis.?National Psoriasis Foundation. June 2, 2022.
  16. Bronckers IMGJ, Paller AS, van Geel MJ, et al. Psoriasis in Children and Adolescents: Diagnosis, Management and Comorbidities.?Paediatric Drugs. June 14, 2015.
  17. Psoriasis and Skin of Color National Psoriasis Foundation. February 16, 2021.
  18. Psoriasis.?National Institute of Arthritis and Musculoskeletal and Skin Diseases. September 2020.
  19. Stawczyk-Macieja M, Rebala K, Szczerkowska-Dobosz A, et al. Evaluation of Psoriasis Genetic Risk Based on Five Susceptibility Markers in a Population From Northern Poland.?PLoS One. September 22, 2016.
  20. Psoriasis.?Cleveland Clinic. September 15, 2022.
  21. Eczema vs. Psoriasis: Similarities, Differences, and Treatments.?Penn Medicine. March 24, 2022.
  22. Scalp Psoriasis.?National Psoriasis Foundation. October 28, 2022.

Additional Sources

Show Less
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news
news