Psoriatic arthritis (PsA) is a type of inflammatory arthritis that affects about 30% of people with psoriasis. It causes stiffness, pain, and swelling in the joints and where tendons and ligaments connect to bones.

People may also experience nail changes and psoriasis skin symptoms, such as plaques and scales.

There are five distinct types of PsA, and a person may develop one type at first and another type later in life.

Doctors define PsA into five classic types based on the number and location of joints affected.

Distal interphalangeal

Distal interphalangeal psoriatic arthritis affects the joints in the fingers. It can cause nail changes, such as pitting, flaking, or separation from the nail bed.

Pain in the finger joints is often one of the first symptoms that people experience. However, only about 5% of people with psoriatic arthritis experience symptoms in these joints. The rest experience pain or stiffness in other joints throughout the body.

Asymmetric oligoarticular

Asymmetric oligoarticular PsA affects less than five joints. It gets the name asymmetric because it affects joints on one side of the body only. For example, a person may experience pain in their right but not their left elbow.

According to a recent study, asymmetric PsA accounts for up to 70% of all PsA occurrences. Symptoms typically begin in one knee.

According to one study, although experts typically agree that oligoarticular PsA affects five or fewer joints. However, some doctors have difficulty diagnosing it and may conclude that a person has polyarthritis.

Symmetric polyarthritis

Polyarthritis affects five or more joints in the body and accounts for about 15% of all cases of PsA. About 50-60% of people with PsA have symmetric polyarthritis, meaning it affects joints on both sides of the body.

Sometimes, people confuse this type of PsA with rheumatoid arthritis.

Spondylitis

Spondylitis refers to inflammation and degenerative changes in the joints of the spine and sacroiliac joints (located in the pelvis and lower spine).

People with other types of arthritis, such as enteropathic arthritis, may also have spondylitis. When spondylitis occurs in people with PsA, it’s known as psoriatic spondylitis. About 20% of people with PsA experience spondylitis.

People with psoriatic spondylitis most often have symptoms in the lumbar (lower) spine, although pain and stiffness can occur anywhere in the spine, neck, or pelvis. Untreated, it can lead to the fusion of the vertebrae.

Arthritis mutilans

This severe condition affects between 1–5% of people living with PsA. Arthritis mutilans damages the joints of the hands, feet, fingers, and wrists. Joints may eventually fuse together.

Although there is no cure for PsA, treatment can help improve a person’s quality of life and prevent the condition from worsening over time.

Doctors may first recommend medications to address symptoms such as swelling and pain. Options include:

  • NSAIDs, such as ibuprofen or naproxen
  • steroid pills or injections into the joints, which people typically use for the short-term treatment of acute symptoms

Systemic treatments reduce the underlying inflammation that causes PsA symptoms.

Disease-modifying antirheumatic drugs (DMARDs) are one type of systemic treatment. They reduce overall inflammation and may help prevent further damage to the joints. Traditional DMARDs include:

  • methotrexate
  • sulfasalazine
  • leflunomide
  • apremilast
  • tofacitinib

Biological therapies are a newer type of DMARD that target specific molecules in the immune system to reduce the inflammation responsible for PsA. They typically cause fewer side effects than traditional DMARDs. Options include:

  • anti-TNF medications, such as:
    • adalimumab
    • certolizumab pegol
    • etanercept
    • golimumab
    • infliximab
  • interleukin inhibitors, such as:
    • ustekinumab
    • secukinumab
    • ixekizumab

Some people with severe PsA may require surgery to fix or fully replace damaged or deformed joints.

Doctors also often recommend physical therapy and regular exercise to increase strength, flexibility, and mobility in the joints and muscles.

How a person experiences PsA impacts their recommended course of treatment. To create a treatment plan, a doctor may assess which type of PsA a person has, as well as their outcomes (or core domains).

These may include:

  • musculoskeletal disease activity, inflammation in the joints, and where tendons or ligaments insert into the bone
  • skin and nail disease activity
  • systemic inflammation
  • fatigue and pain
  • overall physical functioning
  • participation in daily life, for example, in family roles, social and leisure activities, and employment
  • emotional well-being (such as stress, self-worth, depressive mood, anxiety)

Research indicates that early treatment for PsA can improve outcomes. Because nearly one-third of people with psoriasis also develop PsA, it is important that people with psoriasis inform their doctor right away if they think they’re experiencing arthritis symptoms.

Home remedies include lifestyle modifications that help address PsA symptoms and improve outcomes. Examples of lifestyle changes include:

  • managing stress
  • practicing meditation and other forms of relaxation
  • regularly exercising
  • avoiding smoking or drinking too much alcohol
  • eating a balanced diet that’s low in sugar, fat, and salt
  • applying hot and cold therapies to the joints
  • protecting the skin, avoiding skin irritants, and managing psoriasis, if present

There are five classic types of PsA. Each type describes the number of joints and the location of joints that are affected.

Treatment varies according to the type of PsA a person has and how it affects them. It’s important for people to notify their doctor or another healthcare professional if they notice changes in their symptoms over time, as they may require a new treatment plan.