Reactive arthritis is joint pain and swelling triggered by an infection in another part of your body — most often your intestines, genitals or urinary tract.
Your knees and the joints of your ankles and feet are the usual targets of reactive arthritis. Inflammation also may affect your eyes, skin and urethra when you have reactive arthritis.
Although reactive arthritis is sometimes called Reiter's syndrome, Reiter's is actually a specific type of reactive arthritis. In Reiter's, inflammation typically affects the eyes and urethra, as well as your joints.
Reactive arthritis isn't common. For most people, signs and symptoms of reactive arthritis come and go, eventually disappearing within 12 months.
The signs and symptoms of reactive arthritis generally start one to three weeks after exposure to a triggering infection. They may include:
Pain and stiffness. The joint pain associated with reactive arthritis most commonly occurs in your knees, ankles and feet. You also might experience pain in your 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.
Swollen toes or fingers. In some cases, your toes or fingers might become so swollen that they resemble sausages.
Certain factors increase your risk of reactive arthritis:
Your age. Reactive arthritis occurs most frequently in people 20 to 40 years old.
Your sex. Women and men are equally likely to develop reactive arthritis in reaction 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 many people who have this marker never develop reactive arthritis.
Reactive arthritis develops in reaction to an infection in another part of your body, often in your intestines, genitals or urinary tract. You may not be aware of the triggering infection because it may cause only mild symptoms or none at all.
Numerous bacteria can cause reactive arthritis. The most common ones include:
Reactive arthritis isn't contagious. However, the bacteria that cause it can be transmitted sexually or in contaminated food. But only a few of the people who are exposed to these bacteria develop reactive arthritis.
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.
Make sure your food is stored at proper temperatures and is cooked properly. These steps can 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. Using condoms may lower your risk.
During the physical exam, your doctor may examine your joints for signs of inflammation such as swelling, warmth and tenderness. Your spine and affected joints may be assessed for range of motion. Your doctor might also check your eyes for inflammation and your skin for rashes.
Your doctor might recommend that a sample of your blood be tested for:
Evidence of past or present infections
Signs of inflammation
Antibodies associated with other types of arthritis
A genetic marker linked to reactive arthritis
Joint fluid tests
Your doctor may use a needle to withdraw a sample of fluid from within an affected joint. This fluid will be tested for:
White blood cell count. If the joint fluid has an increased number of white blood cells, it may indicate inflammation or an infection.
Infections. If your joint fluid contains bacteria, you may have septic arthritis, which can result in severe joint damage.
Crystals. If uric acid crystals are found in your joint fluid, you may have gout. This very painful type of arthritis often affects the big toe.
X-rays of your low back, pelvis and joints can indicate whether you have any of the characteristic signs of reactive arthritis. X-rays can also rule out other types of arthritis.
The goal of treatment is to manage your symptoms and treat any underlying infections that may still be present.
If your reactive arthritis was triggered by a bacterial infection, your doctor might prescribe an antibiotic. Which antibiotic you take depends on the bacteria that are present.
For your arthritis signs and symptoms, your doctor may recommend:
Nonsteroidal anti-inflammatory drugs (NSAIDs). Prescription NSAIDs, such as indomethacin (Indocin), can relieve the inflammation and pain of reactive arthritis.
Corticosteroids. Injection of a corticosteroid into affected joints can reduce inflammation and allow you to return to your normal activity level.
Rheumatoid arthritis drugs. Limited evidence suggests that medications such as sulfasalazine (Azulfidine), methotrexate (Trexall) or etanercept (Enbrel) can relieve pain and stiffness for some people with reactive arthritis.
Exercise can help people with arthritis improve joint function. A physical therapist can provide you with specific exercises for your joints and muscles. Strengthening exercises are valuable for developing the muscles around your affected joints, which increase the joint's support. Performing range-of-motion exercises can increase your joints' flexibility and reduce stiffness.