Introduction of reactive arthritis

Reactive arthritis is a condition that causes inflammation (redness and swelling) in various places in the body.

It usually develops following an infection, and in most cases clears up without causing future problems.

The three most common places affected by reactive arthritis are:

• the joints (arthritis), which can cause symptoms such as pain and stiffness
• the eyes (conjunctivitis), which can cause symptoms such as eye pain and redness of the eyes
• the urethra (urethritis), which can cause pain when urinating (the urethra is the tube that carries urine out of the body) 

Read more about the symptoms of reactive arthritis.

Seeking medical help

It’s recommended you contact your GP if you have any swollen and painful joints, especially if you have recently had diarrhoea or problems passing urine.

Causes

Reactive arthritis develops after an infection, typically after a sexually transmitted infection (STI) such as chlamydia, or an infection of the digestive system.

For reasons that are still unclear, two to four weeks after the infection has passed the immune system (the body’s defence against infection) appears to malfunction and starts attacking healthy tissue, causing it to become inflamed. 

Read more about the causes of reactive arthritis.

Diagnosis and treatment

There is no single test for reactive arthritis, although blood tests and X-rays may be used to rule out other causes of your symptoms. An assessment of your symptoms and recent medical history – such as whether you may have recently had a digestive or sexually transmitted infection – should help lead to a diagnosis.

There is currently no cure for reactive arthritis, but the condition usually improves after three to 12 months. Meanwhile, treatment can help relieve symptoms such as pain and stiffness.

Mild to moderate symptoms can usually be controlled using non-steroidal anti-inflammatory drugs (NSAIDs) painkillers, such as ibuprofen.

More severe symptoms will usually require steroid medication (corticosteroids) or disease-modifying anti-rheumatic drugs (DMARDs).

Read more about the treating reactive arthritis.

Who is affected?

Reactive arthritis is a relatively uncommon condition. It is estimated that one in every 2,500 people will develop a new case of reactive arthritis in any given year in the UK.

Reactive arthritis that occurs after a digestive infection affects men and women equally.

Reactive arthritis that occurs after a sexually transmitted infection is much more common in men, who account for nine out of 10 cases.

Most cases of reactive arthritis develop in people who are 20-40 years of age, although it can affect children.