Overview

Psoriasis is a skin disease that causes a rash with itchy, scaly patches, most commonly on the knees, elbows, trunk and scalp.

Psoriasis is a common, long-term (chronic) disease with no cure. It can be painful, interfere with sleep and make it hard to concentrate. The condition tends to go through cycles, flaring for a few weeks or months, then subsiding for a while. Common triggers in people with a genetic predisposition to psoriasis include infections, cuts or burns, and certain medications.

Treatments are available to help you manage symptoms. And you can try lifestyle habits and coping strategies to help you live better with psoriasis.

Symptoms

Common signs and symptoms of psoriasis include:

  • A patchy rash that varies widely in how it looks from person to person, ranging from spots of dandruff-like scaling to major eruptions over much of the body
  • Rashes that vary in color, tending to be shades of purple with gray scale on brown or Black skin and pink or red with silver scale on white skin
  • Small scaling spots (commonly seen in children)
  • Dry, cracked skin that may bleed
  • Itching, burning or soreness
  • Cyclic rashes that flare for a few weeks or months and then subside

There are several types of psoriasis, each of which varies in its signs and symptoms:

  • Plaque psoriasis. The most common type of psoriasis, plaque psoriasis causes dry, itchy, raised skin patches (plaques) covered with scales. There may be few or many. They usually appear on the elbows, knees, lower back and scalp. The patches vary in color, depending on skin color. The affected skin might heal with temporary changes in color (post inflammatory hyperpigmentation), particularly on brown or Black skin.
  • Nail psoriasis. Psoriasis can affect fingernails and toenails, causing pitting, abnormal nail growth and discoloration. Psoriatic nails might loosen and separate from the nail bed (onycholysis). Severe disease may cause the nail to crumble.
  • Guttate psoriasis. Guttate psoriasis primarily affects young adults and children. It's usually triggered by a bacterial infection such as strep throat. It's marked by small, drop-shaped, scaling spots on the trunk, arms or legs.
  • Inverse psoriasis. Inverse psoriasis mainly affects the skin folds of the groin, buttocks and breasts. It causes smooth patches of inflamed skin that worsen with friction and sweating. Fungal infections may trigger this type of psoriasis.
  • Pustular psoriasis. Pustular psoriasis, a rare type, causes clearly defined pus-filled blisters. It can occur in widespread patches or on small areas of the palms or soles.
  • Erythrodermic psoriasis. The least common type of psoriasis, erythrodermic psoriasis can cover the entire body with a peeling rash that can itch or burn intensely. It can be short-lived (acute) or long-term (chronic).

When to see a doctor

If you suspect that you may have psoriasis, see your health care provider. Also seek medical care if your condition:

  • Becomes severe or widespread
  • Causes you discomfort and pain
  • Causes you concern about the appearance of your skin
  • Doesn't improve with treatment

Mayo Clinic Minute: Fingernails are clues to your health

Vivien Willliams: Your fingernails are clues to your overall health. Many people develop lines or ridges from the cuticle to the tip.

Rachel Miest, M.D., Department of Dermatology, Mayo Clinic: Those are actually completely fine and just a part of normal aging.

Ms. Williams: But Dr. Rachel Miest says there are other nail changes you should not ignore that may indicate …

Dr. Miest: liver problems, kidney problems, nutritional deficiencies …

Ms. Williams: And other issues. Here are six examples: No. 1 is pitting. This could be a sign of psoriasis. Two is clubbing. Clubbing happens when your oxygen is low and could be a sign of lung issues. Three is spooning. It can happen if you have iron-deficient anemia or liver disease. Four is called "a Beau's line." It's a horizontal line that indicates a previous injury or infection. Five is nail separation. This may happen as a result of injury, infection or a medication. And six is yellowing of the nails, which may be the result of chronic bronchitis.

For the Mayo Clinic News Network, I'm Vivien Williams.

From Mayo Clinic to your inbox

Sign up for free and stay up to date on research advancements, health tips, current health topics, and expertise on managing health. Click here for an email preview.

To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and website usage information with other information we have about you. If you are a Mayo Clinic patient, this could include protected health information. If we combine this information with your protected health information, we will treat all of that information as protected health information and will only use or disclose that information as set forth in our notice of privacy practices. You may opt-out of email communications at any time by clicking on the unsubscribe link in the e-mail.

Causes

Psoriasis is thought to be an immune system problem that causes skin cells to grow faster than usual. In the most common type of psoriasis, known as plaque psoriasis, this rapid turnover of cells results in dry, scaly patches.

The cause of psoriasis isn't fully understood. It's thought to be an immune system problem where infection-fighting cells attack healthy skin cells by mistake. Researchers believe that both genetics and environmental factors play a role. The condition is not contagious.

Psoriasis triggers

Many people who are predisposed to psoriasis may be free of symptoms for years until the disease is triggered by some environmental factor. Common psoriasis triggers include:

  • Infections, such as strep throat or skin infections
  • Weather, especially cold, dry conditions
  • Injury to the skin, such as a cut or scrape, a bug bite, or a severe sunburn
  • Smoking and exposure to secondhand smoke
  • Heavy alcohol consumption
  • Certain medications — including lithium, high blood pressure drugs and antimalarial drugs
  • Rapid withdrawal of oral or injected corticosteroids

Risk factors

Anyone can develop psoriasis. About a third of instances begin in childhood. These factors can increase the risk of developing the disease:

  • Family history. The condition runs in families. Having one parent with psoriasis increases your risk of getting the disease. And having two parents with psoriasis increases your risk even more.
  • Smoking. Smoking tobacco not only increases the risk of psoriasis but also may increase the severity of the disease.

Complications

If you have psoriasis, you're at greater risk of developing other conditions, including:

  • Psoriatic arthritis, which causes pain, stiffness, and swelling in and around the joints
  • Temporary skin color changes (post-inflammatory hypopigmentation or hyperpigmentation) where plaques have healed
  • Eye conditions, such as conjunctivitis, blepharitis and uveitis
  • Obesity
  • Type 2 diabetes
  • High blood pressure
  • Cardiovascular disease
  • Other autoimmune diseases, such as celiac disease, sclerosis and the inflammatory bowel disease called Crohn's disease
  • Mental health conditions, such as low self-esteem and depression

Psoriasis care at Mayo Clinic

Feb. 07, 2024
  1. AskMayoExpert. Psoriasis. Mayo Clinic; 2021.
  2. Dinulos JGH. Psoriasis and other papulosquamous diseases. In: Habif's Clinical Dermatology. 7th ed. Elsevier; 2021. https://www.clinicalkey.com. Accessed March 5, 2020.
  3. Psoriasis clinical guideline. American Academy of Dermatology. https://www.aad.org/member/clinical-quality/guidelines/psoriasis. Accessed March 5, 2020.
  4. Aloe. Natural Medicines. https://naturalmedicines.therapeuticresearch.com. Accessed March 6, 2020.
  5. Bolognia JL, et al., eds. Psoriasis. In: Dermatology. 4th ed. Elsevier; 2018. https://www.clinicalkey.com. Accessed March 5, 2020.
  6. Richard EG. Psoralen plus ultraviolet A (PUVA) photochemotherapy. https://www.uptodate.com/contents/search. Accessed March 16, 2020.
  7. Feldman SR, et al. Treatment of psoriasis in adults. https://www.uptodate.com/contents/search/. Accessed March 16, 2020.
  8. Aromatherapy. Natural Medicines. https://naturalmedicines.therapeuticresearch.com. Accessed March 6, 2020.
  9. Fish oil. Natural Medicines. https://naturalmedicines.therapeuticresearch.com. Accessed March 6, 2020.
  10. Kermott CA, et al., eds. Psoriasis. In: Mayo Clinic Book of Home Remedies. 2nd ed. Time; 2017.
  11. Oregon grape. Natural Medicines. https://naturalmedicines.therapeuticresearch.com. Accessed March 16, 2020.
  12. Bolognia JL, et al., eds. Ultraviolet therapy. In: Dermatology. 4th ed. Elsevier; 2018. https://www.clinicalkey.com. Accessed March 5, 2020.
  13. Bolognia JL, et al., eds. Systemic immunomodulators. In: Dermatology. 4th ed. Elsevier; 2018. https://www.clinicalkey.com. Accessed March 5, 2020.
  14. Psoriasis: Causes. American Academy of Dermatology. https://www.aad.org/public/diseases/psoriasis/insider/diet. Accessed March 17, 2020.
  15. Healthy diet and other lifestyle changes that can improve psoriasis. American Academy of Dermatology. https://www.aad.org/public/diseases/psoriasis/insider/diet. Accessed March 17, 2020.
  16. Gibson LE (expert opinion). Mayo Clinic. March 26, 2020.
  17. Sokumbi O (expert opinion). Mayo Clinic. Nov. 1, 2021.
  18. Kelly AP, et al. Psoriasis. In: Taylor and Kelly's Dermatology for Skin of Color. 2nd ed. McGraw Hill; 2016. https://accessmedicine.mhmedical.com. Accessed Sept. 13, 2021.
  19. Menter A, et al. Joint AAD-NPF guidelines of care for the management and treatment of psoriasis with biologics. Journal of the American Academy of Dermatology. 2018; doi:10.1016/j.jaad.2018.11.057.
  20. Office of Patient Education. Psoriasis. Mayo Clinic; 2008.
  21. Managing itch. National Psoriasis Foundation. https://www.psoriasis.org/life-with-psoriasis/managing-itch. Accessed Nov. 12, 2019.
  22. High WA. Special considerations in skin of color. In: Dermatology Secrets. Elsevier; 2021. https://www.clinicalkey.com. Accessed May 5, 2021.
  23. Griffiths CEM, et al. A multidimension assessment of the burden of psoriasis: Results from a multinational dermatologist and patient survey. British Journal of Dermatology. 2018; doi:10.111/bjd.16332.
  24. Feldman SR, et al. Psoriasis: Epidemiology, clinical manifestations, and diagnosis. https://www.uptodate.com/contents/search/. Accessed Sept. 15, 2021.
  25. Nogueira M, et al. Targeted therapy for pediatric psoriasis. Paediatric Drugs. 2021; doi:10.1007/s40272-021-00443-5.
  26. Elmets CA, et al. Joint AAD-NPF guidelines of care for the management and treatment of psoriasis with topical therapy and alternative medicine modalities for psoriasis severity measures. Journal of the American Academy of Dermatology. 2021; doi.10.1016.j.jaad.2020.07.087.
  27. Dietary modifications. National Psoriasis Foundation. https://www.psoriasis.org/dietary-modifications/. Accessed Oct. 20, 2021.
  28. Ford AR, et al. Dietary recommendations for adults with psoriasis or psoriatic arthritis from the medical board of the National Psoriasis Foundation: A systematic review. JAMA Dermatology. 2018; doi:10.1001/jamadermatol.2018.1412.

Related

Associated Procedures

News from Mayo Clinic