Connect with others who understand.

sign up log in
About MyPsoriasisTeam

Psoriatic Arthritis Causes

Updated on March 01, 2022
Medically reviewed by
Ariel D. Teitel, M.D., M.B.A.
Article written by
Kristopher Bunting, M.D.

  • Although the exact cause of psoriatic arthritis (PsA) is unknown, researchers have identified several risk factors.
  • Psoriasis is the most significant risk factor for psoriatic arthritis.
  • Family history of psoriasis or arthritis is a risk factor for PsA.

Psoriatic arthritis, also called psoriatic spondylitis, is a type of inflammatory arthritis. PsA occurs in about one-third of people with psoriasis, causing pain and inflammation in joints throughout the body. The causes of PsA are not fully understood, but researchers have identified several genetic and environmental risk factors.

What Causes Psoriatic Arthritis?

Psoriatic arthritis is an autoimmune disease, meaning the body’s immune system mistakenly attacks healthy cells and tissues as if they were viruses or bacteria. In psoriatic arthritis, the immune system attacks the ligaments and joints, leading to inflammation and damage.

Psoriatic arthritis is part of a family of related autoimmune disorders collectively called spondylitis, or spondyloarthritis.

The cause of psoriatic arthritis is not understood. However, rheumatologists and researchers believe that the onset of psoriatic arthritis can be triggered by a combination of biological and environmental factors.

Genetic Causes

Research has identified genetic factors associated with the development of PsA. Like other types of spondyloarthritis, PsA has been linked to specific variations on certain inherited genes — such as HLA-B27 — that are involved in the immune system. Researchers have identified several such genes.

Immunological Factors

An abnormal immune response is responsible for causing symptoms of all types of inflammatory arthritis. They can involve a variety of inflammatory mediators, substances in the body that promote inflammation.

T cells, a type of immune cell, are heavily involved in psoriatic arthritis. These cells release proteins called cytokines — chemical messengers that stimulate inflammation. This inflammation causes joint swelling, pain, and damage. Studies show that higher numbers or activity of these T cells and the cytokines they release are linked to PsA symptoms and severity.

Many treatments for psoriatic arthritis specifically target these immune responses. Many biologic disease-modifying antirheumatic drugs (DMARDs) work by helping control the immune response in PsA.

Drugs such as Orencia (abatacept) work by controlling T cell activity, turning down the immune response mediated by T cells and cytokines. Other biologic drugs inhibit tumor necrosis factor (TNF), a potent proinflammatory cytokine. TNF inhibitors include drugs such as Humira (adalimumab), Enbrel (etanercept), and Remicade (infliximab).

Other biologics used to treat PsA, such as Cosentyx (secukinumab) and Stelara (ustekinumab), target a type of cytokines called interleukins.

A newer class of biologics, called Janus kinase (JAK) inhibitors, are also being used to treat PsA. Drugs such as Rinvoq (upadacitinib) and Xeljanz (tofacitinib) treat PsA by blocking the action of a variety of pro-inflammatory cytokines.

Environmental Causes

Research has found that certain infections may contribute to the development of PsA.

In particular, infection with Streptococcus pyogenes, which causes strep throat, seems to correlate with increased PsA risk. Other infections believed to trigger PsA include the sexually transmitted disease chlamydia and bacteria that cause infectious diarrhea, including species of Campylobacter and Yersinia.

Several viral infections may possibly be linked to PsA development, including HIV and hepatitis C. Viruses believed to cause rheumatoid arthritis may also cause PsA, including parvovirus B19, cytomegalovirus, and Epstein-Barr virus.

Other environmental factors that may potentially cause psoriatic arthritis include physical trauma and injuries as well as certain work-related physical activities.

People with psoriasis can experience what is known as the Koebner phenomenon. This phenomenon causes new skin lesions to appear at the site of skin injuries, including scratches, cuts, and burns. Even minor injuries can induce a mild immune response, but in susceptible individuals, this can cause new autoimmune lesions to appear.

This Koebnerization effect also appears to affect tissues such as tendons in people with PsA. This may explain how work-related PsA develops. Research has found that people who work in jobs that involve repeated heavy lifting (100 pounds per hour or more) and pushing heavy loads (more than 200 pounds per hour) are more likely to develop PsA.

Do you have psoriatic arthritis?
Click here to share your experience in the comments below.

What Are the Risk Factors for Psoriatic Arthritis?

Many risk factors have been associated with PsA. Additional research is needed, however, to determine why and how they contribute to disease.

Psoriasis

Psoriasis, a skin condition characterized by scaly lesions (plaques), is the most significant risk factor for PsA. However, people without skin psoriasis can also develop psoriatic arthritis. PsA develops in nearly 30 percent of people with psoriasis, most commonly about 10 years after skin symptoms arise. In approximately 10 percent to 15 percent of people, psoriatic arthritis symptoms begin before skin psoriasis develops.

People with more severe psoriasis have a higher risk of PsA. People with psoriasis lesions or plaques on their nails (nail pitting), scalp, or genital region are also more likely to develop PsA.

Family History

Psoriatic arthritis runs in families. Nearly 40 percent of people with psoriatic arthritis have a family member with psoriasis or arthritis. Combined with the known association between PsA and certain inherited genes, this supports the assertion that genetics play a significant role in the development of psoriatic arthritis.

Race and Ethnicity

Psoriatic arthritis is significantly more prevalent in white people. However, studies have shown that Asian and Hispanic people tend to present with more extensive and severe PsA. Additionally, research has found that Pakistani populations have a higher risk of developing PsA based on family history, even higher than white populations.

Gender

People of any sex are equally likely to develop psoriatic arthritis. Some studies have suggested a link between hormones and PsA, but no definite connection has been proven.

Age

PsA can occur at any age. Psoriatic arthritis usually appears between the ages of 30 and 50, although children with psoriasis are also at risk.

Other Environmental Factors

Other environmental risk factors for PsA include:

  • Certain infections
  • Infections requiring antibiotics
  • Physical injuries
  • Work involving moving heavy loads repeatedly

Talk With Others Who Understand

MyPsoriasisTeam is the social network for people and their loved ones with psoriasis and psoriatic arthritis. More than 100,000 members come together to ask questions, give advice, and share their stories with others who understand life with psoriasis and psoriatic arthritis.

Do you have psoriatic arthritis? Share your experience in the comments below, or start a conversation by posting on MyPsoriasisTeam.

References
  1. About Psoriatic Arthritis — National Psoriasis Foundation
  2. Psoriatic Arthritis — American College of Rheumatology
  3. Eye Inflammation and Psoriatic Arthritis — National Psoriasis Foundation
  4. Psoriatic Arthritis — Arthritis Foundation
  5. Psoriatic Arthritis — Mayo Clinic
  6. Psoriatic Arthritis — F1000 Research
  7. DMARDs — Arthritis Foundation
  8. Tumor Necrosis Factor Inhibitors in Psoriatic Arthritis — Expert Review of Clinical Pharmacology
  9. Infections and the Risk of Psoriatic Arthritis Among Psoriasis Patients: A Systematic Review — Rheumatology International
  10. Physical Trauma Is Associated With the Onset of Psoriatic Arthritis Among Those With Psoriasis — Spondylitis Association of America
  11. Association Between Environmental Factors and Onset of Psoriatic Arthritis in Patients With Psoriasis — Arthritis Care & Research
  12. Koebner Phenomenon — StatPearls
  13. Innate and Adaptive Immune Responses in Wound Epithelialization — Advances in Wound Care
  14. ‘Deep Koebner’ Phenomenon of the Flexor Tendon-Associated Accessory Pulleys as a Novel Factor in Tenosynovitis and Dactylitis in Psoriatic Arthritis — Annals of the Rheumatic Diseases
  15. Psoriatic Arthritis: State of the Art Review — Clinical Medicine Journal
  16. The Epidemiology Psoriatic Arthritis — Rheumatic Disease Clinics of North America
  17. Ethnicity Affects the Presenting Severity of Psoriasis — Journal of the American Academy of Dermatology
  18. Cross-Sectional Study Assessing Family Members of Psoriatic Arthritis Patients Affected by the Same Disease: Differences Between Caucasian, South Asian and Afro-Caribbean Populations Living in the Same Geographic Region — International Journal of Rheumatic Diseases
All updates must be accompanied by text or a picture.
Ariel D. Teitel, M.D., M.B.A. is the clinical associate professor of medicine at the NYU Langone Medical Center in New York. Review provided by VeriMed Healthcare Network. Learn more about him here.
Kristopher Bunting, M.D. studied chemistry and life sciences at the U.S. Military Academy, West Point, and received his doctor of medicine degree from Tulane University. Learn more about him here.

Related articles

About 30 percent of people with psoriasis also suffer from a more severe progression of the...

Risk Factors for Psoriatic Arthritis in Those With Psoriasis

About 30 percent of people with psoriasis also suffer from a more severe progression of the...
People who smoke have a higher risk for developing psoriasis than the general population. Both...

Does Smoking Raise the Risk for Developing Psoriasis and Psoriatic Arthritis?

People who smoke have a higher risk for developing psoriasis than the general population. Both...
Psoriasis is an inflammatory skin condition that creates red, scaly patches on the skin known as...

Can Strep Throat Trigger the Development of Psoriasis?

Psoriasis is an inflammatory skin condition that creates red, scaly patches on the skin known as...
Psoriatic arthritis (PsA) is a type of chronic inflammatory arthritis (joint disease) that is...

Is Gut Health a Factor in Developing Psoriatic Arthritis?

Psoriatic arthritis (PsA) is a type of chronic inflammatory arthritis (joint disease) that is...
Stress causes neurological and hormonal changes that can trigger psoriasis.Smoking, alcohol, and...

What Causes Psoriasis Flares?

Stress causes neurological and hormonal changes that can trigger psoriasis.Smoking, alcohol, and...
Weather can affect your chances of having a psoriasis flare.Winter can be especially harsh for...

Weather and Psoriasis Flares

Weather can affect your chances of having a psoriasis flare.Winter can be especially harsh for...

Recent articles

Erythrodermic psoriasis affects an estimated 1 percent to 2.25 percent of people living with...

Erythrodermic Psoriasis: Symptoms and Photos

Erythrodermic psoriasis affects an estimated 1 percent to 2.25 percent of people living with...
Anemia is a common comorbidity (co-occurring condition) in people with psoriasis, psoriatic...

Psoriasis and Anemia: What’s the Connection?

Anemia is a common comorbidity (co-occurring condition) in people with psoriasis, psoriatic...
Retinoids are often used to treat psoriasis, a skin condition that causes inflammation and leads...

Your Guide to Retinoids for Psoriasis

Retinoids are often used to treat psoriasis, a skin condition that causes inflammation and leads...
Psoriasis is not a fatal disease, but it does increase the risk of comorbidities (coinciding...

Does Psoriasis Affect Life Expectancy?

Psoriasis is not a fatal disease, but it does increase the risk of comorbidities (coinciding...
In partnership with GoodRx
Living in fear of a psoriasis flare-up can keep you from doing things you once enjoyed. However,...

Swimming With Psoriasis: Tips for Enjoying the Water

Living in fear of a psoriasis flare-up can keep you from doing things you once enjoyed. However,...
MyPsoriasisTeam My psoriasis Team

Thank you for signing up.

close