What Is Reactive Arthritis?

Reactive arthritis is a type of inflammatory arthritis that can develop after certain infections, especially infections involving the urinary tract or digestive system.

The condition most often affects the joints, but it can also involve the eyes, skin, and urinary tract. Reactive arthritis is linked to bacterial infections, including sexually transmitted infections and some foodborne illnesses.

Common triggers include:

• Chlamydia infection
• Salmonella
• Shigella
• Campylobacter
• Yersinia

Some people may have a higher genetic risk, especially those with the HLA-B27 gene marker.

Symptoms

Reactive arthritis symptoms can vary from person to person. Joint symptoms are often the first sign, but other parts of the body may also be affected. Symptoms usually begin several days or weeks after the original infection.

Common symptoms include:

• Pain and swelling in the knees, ankles, or feet
• Joint stiffness
• Heel pain
• Lower back discomfort
• Pain or burning during urination
• Eye redness or irritation
• Blurred vision
• Fatigue
• Swollen fingers or toes

How Is It Diagnosed?

Healthcare providers diagnose reactive arthritis by reviewing symptoms, recent illnesses, and medical history. A physical exam can help identify joint swelling and areas of inflammation.

Testing may include:

• Blood tests to measure inflammation
• Urine or stool testing for infection
• Joint fluid analysis
• X-rays if joint damage or spine involvement is suspected

Because no single test confirms reactive arthritis, providers often rule out other types of arthritis during the evaluation.

How Is It Treated?

Treatment focuses on controlling inflammation, relieving symptoms, and treating any underlying infection.

Treatment options may include:

• Antibiotics for bacterial infections
• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Corticosteroids
• Physical therapy and exercise
• Low-dose radiation therapy
• Medications to control ongoing inflammation in chronic cases

Many people improve within a few months, especially with early treatment and supportive care. Some people may experience future flare-ups or longer-lasting joint symptoms.