Reactive arthritis involves joint pain and swelling that occurs as an immune response to an infection elsewhere in the body, leading to inflammation particularly in the joints. While the initial infection might be mild or even unnoticed, its presence can set off a complex immune reaction.
Understanding Reactive Arthritis
Reactive arthritis is a form of inflammatory arthritis triggered by an infection in another bodily system, most commonly the intestines, genitals, or urinary tract. The body’s immune system, in its effort to fight the initial infection, mistakenly targets healthy tissues, especially within the joints. This results in pain, swelling, and stiffness in affected areas.
The condition often impacts larger joints like the knees, ankles, and feet. Inflammation can also extend to other sites, including the eyes, skin, and the urethra. Unlike infectious arthritis, the joints themselves are not typically infected with the bacteria that caused the initial trigger.
The Link to Chlamydia
Chlamydia trachomatis, a common bacterium transmitted sexually, is a frequent trigger for reactive arthritis. When a chlamydial infection occurs in the genitourinary system, it can initiate an immune response that subsequently leads to joint inflammation. This phenomenon is often described as “post-infectious” or “sterile” arthritis, implying the bacteria are not directly present in the inflamed joint.
However, emerging research suggests that Chlamydia bacteria might persist in a metabolically active state within joint tissues, even if standard cultures are negative. This persistent presence could contribute to the ongoing immune reaction and inflammation seen in individuals. Only a small percentage of people infected with Chlamydia—typically between 1% and 3%—will go on to develop reactive arthritis. Symptoms of reactive arthritis typically emerge one to four weeks after the initial chlamydial infection.
Recognizing the Symptoms
A classic pattern of symptoms includes arthritis, inflammation of the urethra (urethritis), and eye inflammation (conjunctivitis). Joint pain, swelling, and stiffness are common, particularly in the knees, ankles, and feet. Some individuals may experience “sausage digits,” where entire fingers or toes become swollen, or heel pain due to inflammation where tendons attach to bone.
Urinary issues, such as increased frequency or discomfort during urination, can occur. Eye symptoms may include redness, irritation, and blurry vision, and in some cases, a more severe inflammation of the inner eye called uveitis. Additional manifestations can involve skin rashes, particularly on the palms and soles (keratoderma blennorrhagicum), mouth sores, or a rash on the penis (circinate balanitis).
Diagnosis and Treatment Approaches
Diagnosing reactive arthritis linked to chlamydia involves a thorough medical evaluation. A healthcare provider will review the patient’s medical history, including any recent infections, and conduct a physical examination to assess joint and other symptoms. Laboratory tests are often used to support the diagnosis and rule out other conditions.
These tests may include blood work for inflammation markers like erythrocyte sedimentation rate (ESR) or C-reactive protein. Tests for Chlamydia infection, using urine or swab samples, are important to identify the triggering pathogen. Genetic testing for the HLA-B27 marker may also be performed, as its presence is associated with a higher risk of developing reactive arthritis, though many individuals with this marker never develop the condition.
Treatment initially focuses on addressing the underlying chlamydial infection with antibiotics. For joint and other symptoms, nonsteroidal anti-inflammatory drugs (NSAIDs) are often prescribed to reduce pain and inflammation. In cases of severe or persistent inflammation, corticosteroids may be used, either orally or through injections into affected joints. For chronic or more severe forms, disease-modifying antirheumatic drugs (DMARDs) like sulfasalazine or methotrexate may be considered to manage the ongoing immune response.
Living with Reactive Arthritis
The course of reactive arthritis is often self-limiting, with symptoms typically resolving within three to twelve months for most individuals. However, some people may experience chronic or recurring arthritis, with symptoms lasting longer or reappearing periodically. Factors such as the presence of the HLA-B27 gene can increase the likelihood of a more prolonged or severe course.
Ongoing medical care is important to monitor the condition and manage any persistent symptoms. Physical therapy can be beneficial in maintaining joint mobility and strength, helping individuals cope with discomfort and stiffness. While reactive arthritis itself is not contagious, the bacterial infections that trigger it, such as chlamydia, can be transmitted to others.