Adults only (18+)

What Is Reactive Arthritis?

Understanding Reactive Arthritis

Reactive arthritis is a type of inflammatory arthritis that develops as a reaction to an infection elsewhere in the body. Unlike other forms of arthritis caused by direct joint damage or autoimmune processes, reactive arthritis occurs when the immune system responds abnormally to infections, often in the urinary tract, genitals or gastrointestinal system. This immune response causes inflammation in the joints, tendons and other tissues, leading to pain and swelling. Reactive arthritis typically affects young adults and can develop suddenly following an infection.

Common Causes and Triggers

The infections that trigger reactive arthritis are usually bacterial. Common culprits include Chlamydia trachomatis, a sexually transmitted infection, and gastrointestinal infections caused by bacteria such as Salmonella, Shigella, Yersinia and Campylobacter. Not everyone who experiences these infections develops reactive arthritis, indicating that genetic factors, such as carrying the HLA-B27 gene, play a role in susceptibility.

Symptoms of Reactive Arthritis

Symptoms often begin within one to four weeks after the initial infection. The hallmark features include joint pain and swelling, most commonly in the knees, ankles and feet. People may also experience inflammation where tendons attach to bones (enthesitis), causing heel pain or discomfort in the soles of the feet. Other symptoms can include redness and pain in the eyes (conjunctivitis or uveitis), urinary symptoms such as burning during urination and, less commonly, mouth ulcers or skin rashes.

Diagnosis

Diagnosing reactive arthritis involves a combination of clinical assessment, patient history of recent infection, blood tests for inflammation markers and genetic testing for HLA-B27. Doctors may also take urine or stool samples to identify the triggering infection. Imaging like X-rays or ultrasound can help assess joint involvement.

Treatment and Management

Treatment focuses on relieving symptoms and addressing the underlying infection. Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used to reduce joint pain and swelling. If the triggering infection is still active, appropriate antibiotics are prescribed. Physical therapy supports joint mobility and function. In persistent or severe cases, disease-modifying medications may be considered. Most people recover fully within six months to a year, but some may develop chronic arthritis.

Summary

Reactive arthritis is an inflammatory joint condition triggered by an infection elsewhere in the body. It causes joint pain, swelling and other symptoms such as eye inflammation and urinary discomfort. Early diagnosis and treatment improve recovery and reduce complications.