Reactive arthritis is joint pain and swelling triggered by an infection in another part of the body — most often the intestines, genitals or urinary tract.

This condition usually targets the knees, ankles and feet. Inflammation also can affect the eyes, skin and the tube that carries urine out of the body (urethra). Previously, reactive arthritis was sometimes called Reiter's syndrome.

Reactive arthritis isn't common. For most people, signs and symptoms come and go, eventually disappearing within 12 months.


The signs and symptoms of reactive arthritis generally start 1 to 4 weeks after exposure to a triggering infection. They might include:

  • Pain and stiffness. The joint pain associated with reactive arthritis most commonly occurs in the knees, ankles and feet. Pain may also occur in the heels, low back or buttocks.
  • Eye inflammation. Many people who have reactive arthritis also develop eye inflammation (conjunctivitis).
  • Urinary problems. Increased frequency and discomfort during urination may occur, as can inflammation of the prostate gland or cervix.
  • Inflammation of tendons and ligaments where they attach to bone (enthesitis). This happens most often in the heels and the sole of the feet.
  • Swollen toes or fingers. In some cases, toes or fingers might become so swollen that they look like sausages.
  • Skin problems. Reactive arthritis can affect skin in a variety of ways, including mouth sores and a rash on the soles of the feet and palms of the hands.
  • Low back pain. The pain tends to be worse at night or in the morning.
Common inflammation sites in reactive arthritis

Inflammation sites

Inflammation often affects these sites in people with reactive arthritis.

When to see a doctor

If you develop joint pain within a month of having diarrhea or a genital infection, contact your health care provider.


Reactive arthritis develops in reaction to an infection in your body, often in your intestines, genitals or urinary tract. You might not be aware of the triggering infection if it causes mild symptoms or none at all.

Numerous bacteria can cause reactive arthritis. Some are transmitted sexually, and others are foodborne. The most common ones include:

  • Campylobacter
  • Chlamydia
  • Clostridioides difficile
  • Escherichia coli
  • Salmonella
  • Shigella
  • Yersinia

Reactive arthritis isn't contagious. However, the bacteria that cause it can be transmitted sexually or in contaminated food. Only a few of the people who are exposed to these bacteria develop reactive arthritis.

Risk factors

Certain factors increase your risk of reactive arthritis:

  • Age. Reactive arthritis occurs most frequently in adults between the ages of 20 and 40.
  • Sex. Women and men are equally likely to develop reactive arthritis in response to foodborne infections. However, men are more likely than are women to develop reactive arthritis in response to sexually transmitted bacteria.
  • Hereditary factors. A specific genetic marker has been linked to reactive arthritis. But most people who have this marker never develop the condition.


Genetic factors appear to play a role in whether you're likely to develop reactive arthritis. Though you can't change your genetic makeup, you can reduce your exposure to the bacteria that may lead to reactive arthritis.

Store your food at proper temperatures and cook it properly. Doing these things help you avoid the many foodborne bacteria that can cause reactive arthritis, including salmonella, shigella, yersinia and campylobacter. Some sexually transmitted infections can trigger reactive arthritis. Use condoms to help lower your risk.

Jan 25, 2022

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  3. Goldman L, et al., eds. The spondyloarthropathies. In: Goldman-Cecil Medicine. 26th ed. Elsevier; 2020. https://www.clinicalkey.com. Accessed Aug. 25, 2021.
  4. Ferri FF. Reactive arthritis (Reiter syndrome). In: Ferri's Clinical Advisor 2022. Elsevier; 2022. https://www.clinicalkey.com. Accessed Aug. 25, 2021.
  5. Reactive arthritis. American College of Rheumatology. https://www.rheumatology.org/I-Am-A/Patient-Caregiver/Diseases-Conditions/Reactive-Arthritis. Accessed Aus. 25, 2021.
  6. AskMayoExpert. Reactive arthritis (adult). Mayo Clinic; 2021.
  7. Reactive arthritis. Arthritis Foundation. https://www.arthritis.org/diseases/reactive-arthritis. Accessed Aug. 25, 2021.


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