Connect with others who understand.

sign up log in
Resources
About MyPsoriasisTeam

Connect with others who understand.

sign up log in
Resources
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 psoriatic arthritis 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 abatacept (sold as Orencia) 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 adalimumab (Humira), etanercept (Enbrel), and infliximab (Remicade).

Other biologics used to treat PsA, such as secukinumab (Cosentyx) and ustekinumab (Stelara), 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 upadacitinib (Rinvoq) and tofacitinib (Xeljanz) 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. According to the National Psoriasis Foundation, 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, according to the American College of Rheumatology. 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, according to the Arthritis Foundation. 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

Some people with psoriasis find that certain factors can trigger flares (periods of worsening...

Psoriasis and Hormones: How Hormonal Changes Can Affect You

Some people with psoriasis find that certain factors can trigger flares (periods of worsening...
Psoriasis occurs when something goes wrong with your immune system. Your immune cells become...

T Cells in Psoriasis: A Simplified Guide

Psoriasis occurs when something goes wrong with your immune system. Your immune cells become...
The risk for developing psoriasis is associated with many factors, including genetics and...

Psoriasis and Ethnicity: Is Race a Risk Factor?

The risk for developing psoriasis is associated with many factors, including genetics and...
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...

Recent articles

Dead Sea salt can be an effective over-the-counter remedy for psoriasis. Dead Sea salt is often...

Does Dead Sea Salt Help Psoriasis?

Dead Sea salt can be an effective over-the-counter remedy for psoriasis. Dead Sea salt is often...
Psoriatic arthritis (PsA) is characterized by joint pain, swelling, and stiffness.A...

Psoriatic Arthritis Symptoms

Psoriatic arthritis (PsA) is characterized by joint pain, swelling, and stiffness.A...
About 30 percent of people with psoriasis will eventually be diagnosed with psoriatic arthritis...

Psoriatic Arthritis in the Hands: Symptoms and Treatment Options

About 30 percent of people with psoriasis will eventually be diagnosed with psoriatic arthritis...
Many people with psoriasis have trouble sticking to their treatment plan, which can lead to poor...

Five Tips for Sticking With Your Psoriasis Treatment

Many people with psoriasis have trouble sticking to their treatment plan, which can lead to poor...
Psoriasis on the scalp is common for those with psoriasis. Discover whether products like Sea Breeze can help with scalp psoriasis.

Does Sea Breeze Help Scalp Psoriasis?

Psoriasis on the scalp is common for those with psoriasis. Discover whether products like Sea Breeze can help with scalp psoriasis.
The Centers for Disease Control and Prevention (CDC) has approved a second COVID-19 booster shot...

What People With Psoriasis Should Know About Getting a Second COVID-19 Booster Shot

The Centers for Disease Control and Prevention (CDC) has approved a second COVID-19 booster shot...
MyPsoriasisTeam My psoriasis Team

Thank you for subscribing!

Become a member to get even more:

sign up for free

close