Sexually Acquired Reactive Arthritis (SARA)

SARA usually causes joint pain and swelling, often together with urinary or eye symptoms, typically developing a few weeks after an infection.

Common symptoms include:

• Pain, swelling, or stiffness affecting joints (commonly knees, ankles, or feet)
• Heel pain or pain where tendons attach (enthesitis)
• Difficulty walking or stiffness, especially in the morning
• Red, painful, or gritty eyes
• Pain when passing urine or genital discharge
• Less commonly, mouth ulcers or rashes affecting the palms or soles

Yes. The triggering infection may cause few or no symptoms, meaning SARA can develop without obvious warning signs.

Joint or eye symptoms are usually noticeable, but they may initially be mild, intermittent, or mistaken for a minor injury or viral illness.

If untreated or persistent, SARA can occasionally become prolonged or recurrent.

Possible complications include:

• Ongoing joint pain, swelling, or stiffness
• Reduced mobility or chronic inflammation
• Eye inflammation (uveitis) that may affect vision
• Persistent skin or nail changes
• Rarely, inflammation affecting the heart or spine

Symptoms usually develop between 1 and 4 weeks after the triggering infection.

They may appear as the original infection is resolving or shortly afterwards, even if the infection caused no noticeable symptoms.

SARA is caused by an immune reaction that develops after certain sexually transmitted infections, most commonly Chlamydia.

The joints themselves are not infected. Instead, the immune system reacts to the infection elsewhere in the body, leading to inflammation that usually develops several days to weeks later.

Not everyone who develops a sexually transmitted infection will develop SARA. Certain genetic and immune factors are thought to influence susceptibility.

Some people are more likely to develop SARA following an infection. Factors associated with increased risk include:

• Recent or untreated infection (particularly chlamydia)
• Genetic susceptibility, especially the HLA-B27 gene
• Young adulthood (most commonly ages 20–40)
• Male sex

Prevention focuses on reducing the risk of sexually transmitted infections and ensuring prompt treatment if infection occurs.

Helpful measures include:

• Using condoms consistently during vaginal, anal, and oral sex
• Attending regular sexual health screening, particularly with new or multiple partners
• Seeking testing promptly if symptoms develop
• Completing any prescribed treatment fully

Yes, although the risk is lower. Condoms significantly reduce the risk of sexually transmitted infections but cannot eliminate it completely.

Some infections may still occur through contact with uncovered skin or if a condom breaks or slips during sex.

No. SARA itself is not contagious and cannot be transmitted through kissing.

It develops as an immune reaction following certain infections that are usually transmitted through sexual contact.

No. SARA cannot be spread through towels, bedding, clothing, or other shared personal items.

It is not directly infectious and only occurs as a reaction following certain infections.

No. SARA cannot be transmitted through blood transfusions.

It is an inflammatory immune reaction rather than an infection itself.

Yes. Reactive arthritis can develop after several different types of infections, including gastrointestinal infections such as food poisoning.

When reactive arthritis is triggered by a sexually transmitted infection — most commonly Chlamydia — it is referred to as sexually acquired reactive arthritis (SARA).

In some cases, the triggering infection may have caused few or no symptoms, or may no longer be detectable by the time joint symptoms develop.

SARA is diagnosed based on your symptoms, recent infection history, and test results. There is no single definitive test.

Assessment usually includes:

• Review of joint, eye, and urinary symptoms
• Sexual health history (symptoms often start 1–4 weeks after infection)
• Physical examination of affected joints and other areas
• STI testing to identify a trigger infection
• Blood tests to check for inflammation and rule out other causes

Testing focuses on identifying the triggering infection and assessing inflammation.

Common tests include:

• STI testing (urine samples and/or swabs)
• Blood tests for inflammation markers (e.g. CRP or ESR)
• HLA-B27 genetic testing in selected cases
• Joint fluid analysis or imaging if the diagnosis is uncertain

A clear symptom pattern and timeline are important for diagnosis.

Helpful features include:

• Recent or untreated sexually transmitted infection
• Symptoms developing 1–4 weeks after infection
• Pain and swelling affecting larger joints (commonly knees or ankles)
• Associated symptoms such as eye irritation or urinary discomfort
• Laboratory evidence of inflammation or infection

Yes. Several conditions can cause similar symptoms and may need to be excluded.

These include:

• Other inflammatory arthritis conditions (e.g. rheumatoid arthritis or psoriatic arthritis)
• Crystal arthritis (e.g. gout)
• Septic arthritis (joint infection)
• Disseminated gonococcal infection
• Reactive arthritis triggered by gastrointestinal infections

Diagnosis is based on combining clinical assessment with investigation results rather than a single test.

Additional investigations may include blood tests, imaging, or joint fluid analysis where needed to confirm the diagnosis or exclude other conditions.

No. Physical examination can identify signs of inflammation but is not enough to confirm the diagnosis on its own.

Laboratory testing and assessment for underlying infection are usually needed.

No. SARA requires medical assessment for accurate diagnosis.

Its symptoms overlap with several other joint and infectious conditions, so testing is important to confirm the cause and guide treatment

Most people improve significantly within 3 to 6 months and recover without permanent joint damage.

However, some individuals may experience recurrent symptoms, prolonged inflammation, or persistent arthritis requiring ongoing monitoring or specialist care.

No. Developing SARA once does not provide immunity against future episodes.

SARA can recur if another triggering infection occurs. Each episode represents a new immune reaction rather than persistence of the original condition.

Reducing the risk of sexually transmitted infections helps lower the chance of recurrence.

Helpful measures include:

• Using condoms consistently
• Attending regular sexual health screening
• Ensuring both you and your partners complete treatment where required
• Seeking testing promptly if symptoms develop

You do not need to disclose SARA itself, but it is important to inform partners about the underlying sexually transmitted infection where appropriate.

This allows partners to access testing and treatment, helping reduce the risk of reinfection and onward transmission.

No. SARA itself is not contagious and cannot be passed directly to another person.

However, the infection that triggered it may still be transmissible. Avoid sexual contact until treatment is completed and follow medical advice regarding testing and partner management.

No. SARA itself cannot be passed to a baby.

However, the underlying infection that triggered SARA (such as Chlamydia) may be transmitted during pregnancy or delivery if untreated, so prompt testing and treatment are important.

The main pregnancy risks are linked to the underlying infection rather than the arthritis itself.

Potential complications of untreated sexually transmitted infections may include:

• Preterm birth
• Low birth weight
• Premature rupture of membranes
• Transmission of infection to the baby during delivery

Management of joint symptoms may also require adjustment, as some anti-inflammatory medications are not recommended during pregnancy.

SARA during pregnancy appears to be uncommon.

Reactive arthritis associated with sexually transmitted infections is reported more frequently in men, although it can occur in people of any sex.

Yes. Treatment focuses on safely treating the underlying infection and managing inflammation during pregnancy.

This may include:

• Pregnancy-safe antibiotics to treat the triggering infection
• Paracetamol for pain relief where appropriate
• Careful use or avoidance of certain anti-inflammatory medications depending on pregnancy stage
• Specialist rheumatology or obstetric input in more severe cases

Treatment is tailored to protect both maternal and fetal health.

Yes. Reducing the risk of sexually transmitted infections and treating infections early may help reduce the risk of SARA.

Helpful measures include:

• Using condoms during sexual activity
• Attending routine antenatal and sexual health screening
• Seeking testing promptly if symptoms develop
• Ensuring partners are tested and treated where appropriate

SARA itself does not affect breast milk or directly harm the baby.

However, joint pain and inflammation may affect mobility, recovery, or childcare activities temporarily. Some medications may also need adjustment to ensure breastfeeding safety.