What Is Psoriatic Arthritis (PsA)?

Reviewed by: HU Medical Review Board | Last reviewed: June 2022

Psoriatic arthritis (PsA) is an inflammatory condition that affects the joints and tendons. It often occurs in people who have psoriasis. Psoriasis is an inflammatory disease of the skin, causing red, scaly patches that are itchy and painful.1

The joint pain of PsA often occurs after a psoriasis diagnosis but not always. It is possible for a person to have joint pain before having skin symptoms. Both PsA and psoriasis are chronic conditions that get worse over time. This is why early diagnosis is so important.1

Symptoms of PsA

Signs and symptoms of PsA vary for each person. There may be periods when symptoms get worse, known as flare-ups, and periods when symptoms go away, known as remission. Some of the most common symptoms of PsA are:1

  • Swelling, stiffness, redness, and heat at the joints
  • Inflammation and pain at the attachment points of ligaments and tendons
  • Joint pain
  • Fatigue
  • Changes to nails (such as discoloration or tiny holes in the surface)

These symptoms often lead to:1

  • Swollen fingers and toes – Swelling in the finger and toe joints is often the first noticeable sign of PsA.
  • Foot pain – Swelling of the tendons and ligaments in the feet can make it difficult to walk and get around.
  • Lower back pain – In some people, PsA affects the joints in the spine. This can lead to arthritis in the back (spondylitis).
  • Eye inflammation (uveitis) – PsA can also affect the eyes, causing pain, redness, and blurry vision. It can even lead to vision loss if left untreated.

Types and patterns of PsA

PsA is defined by 5 clinical patterns:2

  • Distal interphalangeal predominant pattern – Primarily affects the joints closest to the nails in the fingers and toes
  • Oligoarticular asymmetrical – Only a few joints are affected and do not match on both sides of the body
  • Polyarticular RA-like – Multiple joints are affected on both sides of the body in a symmetric pattern, similar to rheumatoid arthritis (RA)
  • Spondylitis – Joints in the spine are affected
  • Arthritis mutilans – Severe form of the disease that causes deformity of the hands, fingers, or toes

What causes PsA?

The exact cause of PsA is unknown. Experts believe it is likely a combination of genetic and environmental factors.1,2

PsA occurs when the body’s immune system mistakenly attacks healthy cells and tissue. This causes inflammation in the joint as well as overproduction of skin cells.1

External factors can sometimes trigger PsA in people who have a family history of the condition. For example, something in the environment, an infection, or trauma to an area of the body might trigger PsA symptoms.1,2

Who gets PsA?

Anyone can get PsA, and the condition affects men and women equally. However, it is more common in people with certain risk factors.1

Risk factors

There are several risk factors for developing PsA, including:1,3

  • Psoriasis – About 1 in 3 people with psoriasis will go on to develop PsA.
  • Family history – People with PsA often have a parent or sibling with the condition as well.
  • Age – While PsA can occur at any age, it is more common in people ages 30 to 55.
  • Obesity – More weight on the joints and ligaments may be a trigger for PsA.


Treatment of PsA depends on the severity and the type of PsA a person has. The goal is to reduce pain and reach remission of the disease. Treatment options for PsA include:4

  • Anti-inflammatory medicines – This is typically the first course of treatment and is used for people with mild PsA.
  • Disease-modifying drugs (DMDs) – These types of prescription drugs are for people with more active or severe PsA. These drugs work with the immune system to help reduce swelling, pain, and inflammation.
  • Physical therapy (PT) – Working with a physical therapist can help strengthen the muscles and joints while improving stability.
  • Weight management – Losing weight can help with joint pain. Weight loss may also make medicines for PsA more effective.

When to see a doctor

Tell your doctor if you start to have joint pain, swelling, or stiffness. And if you have psoriasis, keep a close eye on any new symptoms that develop.

The earlier PsA is diagnosed and treated, the better the outcomes. While there is currently no cure for PsA, certain medicines and therapies can help lessen symptoms and improve quality of life.4

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