Psoriasis is an autoimmune disorder that causes raised, itchy, scaly patches on the skin. It can show up anywhere on your body, depending on the type of psoriasis you have. Psoriasis is not curable, but it can be controlled with treatment. Treatment options include creams and ointments, light therapy, and oral or injectable medications.

Key Terms

Frequently Asked Questions

  • Is psoriasis contagious?

    Many rashes are contagious, but psoriasis is not.

    This disease can run in families, which can lead to confusion about transmission. However, researchers believe this is due to a genetic glitch in the immune system and not anything you can “catch.”

  • What does psoriasis look like?

    The look varies by type:

  • What causes psoriasis? Is it an autoimmune disease?

    Yes, psoriasis is an autoimmune disease. Experts still don’t know why, but the immune system mistakenly attacks healthy skin or nail tissues like it would a real threat, such as a virus.

    Researchers believe a genetic predisposition combines with other factors—such as obesity, stress, or certain medical conditions—to trigger the disorder.

  • What is plaque psoriasis?

    Plaque psoriasis is by far the most common type of psoriasis. It’s characterized by well-defined patches of discolored skin that are itchy, scaly, and flaky. These are called plaques, and they’re caused by skin cells reproducing too quickly, so that they build up on the outermost layer of skin.

  • Is psoriasis itchy?

    Most types of psoriasis are extremely itchy, especially erythrodermic, guttate, and plaque psoriasis. This is due to dry, flaking, and sometimes peeling or cracking skin.

    These and other types of psoriasis may also include pain, which can be severe in some cases.

What Psoriasis Looks Like Under the Skin

Explore an interactive model showing how a psoriasis rash affects the outermost layer of the skin. This layer is typically comprised of a barrier of dead skin cells that continuously shed and are replaced by new cells. In psoriasis, however, the dead skin cells build upon each other, forming a thick, tough layer of cells that eventually flake off.

Page Sources
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  2. U.S. Centers for Disease Control and Prevention. What is Psoriasis? Updated August 18, 2020.

  3. Kim WB, Jerome D, Yeung J. Diagnosis and management of psoriasis. Can Fam Physician. 2017;63(4):278‐285.

  4. Bhatia, B., Millsop, J.; Debbaneh, M. et al. Diet and psoriasis, part II: Celiac disease and role of a gluten-free diet. J Am Acad of Dermatol. 2014;71(2):350-8. doi:10.1016/j.jaad.2014.03.017

  5. Roberson ED, Bowcock AM. Psoriasis genetics: breaking the barrier. Trends Genet. 2010;26(9):415–423. doi:10.1016/j.tig.2010.06.006

  6. National Psoriasis Foundation. Life with psoriasis. Updated October 2, 2020.