Why Psoriasis Is an Autoimmune Disease

Table of ContentsView AllTable of ContentsWhat Is Autoimmunity?Causes and Risk FactorsTreatment Options

Table of ContentsView All

View All

Table of Contents

What Is Autoimmunity?

Causes and Risk Factors

Treatment Options

Psoriasisis anautoimmune disease, meaning that the body’simmune systemturns on itself and attacks normal cells and tissues—in this case, skin cells known askeratinocytes.

This article explains what autoimmune diseases are and the various immune mechanisms that lead to psoriasis. It also describes the risk factors for this autoimmune skin disease and how it is treated.

2:076 Myths About Psoriasis

2:07

6 Myths About Psoriasis

Psoriasis and the Immune System

If you have an autoimmune disease, your immune system responds abnormally to a body part, such as the skin, a joint, or the intestine. Psoriasis is one example of at least 28 diseases classified as autoimmune and possibly up to 150 in total, according to the National Institutes of Health.

The immune system is meant to defend the body against foreign invaders. But with psoriasis, the immune system regards skin cells as foreign and mounts an assault in the form of targetedinflammation.

With an autoimmune disease, there are several “players” involved in the abnormal immune response, namely:

Under normal circumstances, skin cells turn over at a steady rate so that old cells can be shed from the surface of the skin (called theepidermis) and replaced with new ones. With psoriasis, the inflammatory autoimmune assault causes skin cells to turn over at a vastly accelerated rate.

Keratinocytes are the most abundant of all skin cells. When these are exposed to autoimmune inflammation, the turnover rate will increase from the normal to 28 to 30 days to a mere 3 to 5 days.

When this happens, skin cells will start to pile up on the surface of the skin and become compressed rather than being shed. This causes the red, scaly, itchy patches recognized asplaques. Plaques most commonly develop on the back of the forearms, shins, navel area, and scalp (although any body part can be affected).

Plaque psoriasisis the most common type of psoriasis, accounting for more than 90% of cases. Less common types includepustular psoriasis(which causes pus-filled lesions),guttate psoriasis(which causes drop-shaped lesions), andinverse psoriasis(which affect skin folds).

Plaque Psoriasis: Pictures and Symptoms of the Types You May See on Your Body

What Causes Psoriasis?

The cause of psoriasis is unknown. Both genetic and environmental factors are believed to play a role in the onset of the disease.

The theory is genetics, either inherited from your parents or acquired later in life, can predispose a person to the disease. Thereafter, exposure to one or more environmental factors, such as an infection, might “confuse” the immune system and cause it to regard the antigen of a normal cell as hostile.

This can cause not only the onset ofpsoriasis symptomsbut also episodicexacerbations(flare-ups).

Risk factors linked to the onset and/or exacerbation of psoriasis include:

How Psoriasis Is Treated

Depending on the severity of symptoms and type of psoriasis involved, the treatment may include some or all of the following:

5 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Boehncke WH, Schön MP.Psoriasis.Lancet.2015;386(9997):983-94. doi:10.1016/s0140-6736(14)61909-7National Academies of Sciences, Engineering and Medicine.Assessment of NIH research on autoimmune diseases.Rosenblum MD, Remedio KA, Abbas AK.Mechanisms of human autoimmunity.J Clin Invest.2015 Jun 1;125(6):2228–33. doi:10.1172/JCI78088Kim W, Jerome D, Yeung J.Diagnosis and management of psoriasis.Can Fam Physician. 2017 Apr;63(4):278-85.Kamiya K, Kishimoto M, Sugai J, Komine M, Ohtsuki M.Risk factors for the development of psoriasis.Int J Mol Sci.2019 Sep;20(18):4347. doi:10.3390/ijms20184347

5 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Boehncke WH, Schön MP.Psoriasis.Lancet.2015;386(9997):983-94. doi:10.1016/s0140-6736(14)61909-7National Academies of Sciences, Engineering and Medicine.Assessment of NIH research on autoimmune diseases.Rosenblum MD, Remedio KA, Abbas AK.Mechanisms of human autoimmunity.J Clin Invest.2015 Jun 1;125(6):2228–33. doi:10.1172/JCI78088Kim W, Jerome D, Yeung J.Diagnosis and management of psoriasis.Can Fam Physician. 2017 Apr;63(4):278-85.Kamiya K, Kishimoto M, Sugai J, Komine M, Ohtsuki M.Risk factors for the development of psoriasis.Int J Mol Sci.2019 Sep;20(18):4347. doi:10.3390/ijms20184347

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Boehncke WH, Schön MP.Psoriasis.Lancet.2015;386(9997):983-94. doi:10.1016/s0140-6736(14)61909-7National Academies of Sciences, Engineering and Medicine.Assessment of NIH research on autoimmune diseases.Rosenblum MD, Remedio KA, Abbas AK.Mechanisms of human autoimmunity.J Clin Invest.2015 Jun 1;125(6):2228–33. doi:10.1172/JCI78088Kim W, Jerome D, Yeung J.Diagnosis and management of psoriasis.Can Fam Physician. 2017 Apr;63(4):278-85.Kamiya K, Kishimoto M, Sugai J, Komine M, Ohtsuki M.Risk factors for the development of psoriasis.Int J Mol Sci.2019 Sep;20(18):4347. doi:10.3390/ijms20184347

Boehncke WH, Schön MP.Psoriasis.Lancet.2015;386(9997):983-94. doi:10.1016/s0140-6736(14)61909-7

National Academies of Sciences, Engineering and Medicine.Assessment of NIH research on autoimmune diseases.

Rosenblum MD, Remedio KA, Abbas AK.Mechanisms of human autoimmunity.J Clin Invest.2015 Jun 1;125(6):2228–33. doi:10.1172/JCI78088

Kim W, Jerome D, Yeung J.Diagnosis and management of psoriasis.Can Fam Physician. 2017 Apr;63(4):278-85.

Kamiya K, Kishimoto M, Sugai J, Komine M, Ohtsuki M.Risk factors for the development of psoriasis.Int J Mol Sci.2019 Sep;20(18):4347. doi:10.3390/ijms20184347

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