Synovitis is a condition wherein the synovial stratum inside the joint has inflammation. While this condition can develop due to overuse of the joint, it primarily occurs with many forms of inflammatory arthritis, including psoriatic arthritis (PsA).

An imaging test of a person with synovitis and psoriatic arthritis.Share on Pinterest
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Joints contain a connective tissue called the synovial stratum inside the joint capsule. This layer is very thin but strong, and it produces and protects synovial fluid, which lubricates the joint.

If the synovial stratum has inflammation due to an injury, a person may have traumatic synovitis. This condition usually resolves with anti-inflammatory medication and rest.

However, synovitis may also occur due to inflammatory arthritis, such as PsA and rheumatoid arthritis (RA).

This article provides an overview of PsA and synovitis and discusses the link between these conditions.

Doctors diagnose PsA with the use of imaging, such as:

The main indicator of PsA is new bone formation on radiographs. However, doctors can see synovitis with MRI and ultrasound.

If a person has synovitis, the synovial stratum appears thicker and denser in an ultrasound. People with PsA are more likely to have synovitis in the tips of the toes and fingers.

Individuals with PsA may also have tenosynovitis, which is inflammation around tendon sheaths. People with tenosynovitis are more likely to have swelling of the fingers and toes, which health experts call dactylitis.

PsA is an inflammatory condition wherein the body attacks the connective tissues of the joints.

It affects around 20–30% of individuals with psoriasis and can cause swelling and pain in joints and tendons throughout the body. Joints usually feel stiffer after rest, such as during sleep or after waking up.

The condition generally develops in people who are 30–50 years of age, although it may present in children.

Symptoms of PsA include:

  • fatigue
  • tenderness, swelling, and pain in tendons
  • swollen fingers and toes
  • stiffness, throbbing, tenderness, and pain in joints
  • limited range of motion
  • uveitis

Synovitis is a condition in which the synovial stratum in the joint has become inflamed. The main symptom a person is likely to experience is pain.

Transient synovitis is a short-lasting swelling of a joint that most often occurs in children aged 3–10 years. This condition can cause pain, and a person may not be able to bear weight on the joint.

Transient synovitis usually resolves within 2 weeks with rest and anti-inflammatory medication.

Traumatic synovitis may occur with the overuse of a joint. A person may experience pain but is unlikely to have any redness or swelling.

Traumatic synovitis usually resolves with rest and anti-inflammatory medication, such as ibuprofen.

Experts do not fully understand the causes of PsA. They believe, however, that it may be due to a combination of environmental and genetic factors that result in inflammation of the skin, joints, and potentially organs.

Up to half of individuals with PsA have a close relative with this condition.

Environmental factors may include:

  • streptococcal infection and antibiotic use
  • skin trauma
  • joint and tendon trauma

There are several causes of synovitis.

Synovitis can result from the overuse of a joint. A person may also experience pain shortly after a new injury. However, this is likely to resolve with rest and anti-inflammatories.

Experts do not fully understand the underlying cause of transient synovitis. Possible causes include:

Synovitis resulting from inflammatory arthritis is due to these conditions attacking joint tissue.

Synovitis resulting from PsA has different characteristics at a microscopic and chemical analysis level than synovitis due to RA, which may help doctors diagnose the former condition.

Most cases of traumatic and transient synovitis will resolve by themselves. An individual can use over-the-counter (OTC) anti-inflammatory medications, such as ibuprofen, to manage pain.

If a person has synovitis as a result of PsA, and OTC pain relievers prove ineffective, healthcare professionals may employ a different treatment strategy.

Doctors may prescribe biological disease-modifying antirheumatic drugs (DMARDs), such as tumor necrosis factor inhibitors and IL-17 inhibitors, if OTC pain relievers do not help.

A doctor may also prescribe synthetic DMARDs, such as methotrexate or sulfasalazine, for people with moderate PsA. However, biologic medications are more effective.

In rare cases, a doctor may recommend a synovectomy. This surgical procedure involves removing parts of the inflamed synovial stratum.

Healthcare professionals may recommend this surgery as part of a treatment plan for inflammatory arthritis, especially RA.

Synovitis is a condition in which the synovial stratum has become inflamed, causing pain and damage in the joints. While this condition may occur with joint injury, it mainly occurs with inflammatory arthritis, such as PsA and RA.

Doctors may see synovitis early with ultrasound. The synovial stratum is thicker and denser, and people with PsA are more likely to have synovitis in the tips of their fingers and toes.

Individuals with PsA are also more likely to have tenosynovitis, leading to inflammation and swelling in the toes and fingers.