What Is Reactive Arthritis?

Introduction

Reactive arthritis is a form of inflammatory arthritis that develops in response to an infection in another part of the body.¹ This condition often manifests itself as joint pain, swelling, and stiffness, typically affecting the large joints such as the knees, ankles, and feet. 

Reactive arthritis is thought to be triggered by certain bacterial or viral infections, most commonly stemming from gastrointestinal (involved in the digestive system) or genitourinary (involved in the reproductive system) origins. This inflammatory response occurs when the body's immune system mistakenly targets healthy joints and tissues in its effort to combat the initial infection. As a result, people with reactive arthritis often experience not only joint pain and swelling but also related symptoms like eye inflammation, skin rashes, and discomfort in the urinary or gastrointestinal tracts.¹

In this article, we will explore the causes, symptoms, diagnosis, and treatment options associated with reactive arthritis.

Symptoms of reactive arthritis

The symptoms of reactive arthritis typically appear after a few days or a few weeks after getting the infection.¹

According to the NHS, the most common symptoms include the following:

1. Joint symptoms

The most common symptoms of reactive arthritis are pain, stiffness, and swelling, which are experienced by most patients.

• Pain in joints, heels, lower back, buttocks
• Stiffness in joints
• Swelling in fingers and toes

2. Genitourinary symptoms

Reactive arthritis can occur due to a urinary tract infection, which can include symptoms such as the following:

• Pain or burning feeling during urination
• Foul-smelling or cloudy urine
• Presence of blood in urine
• Increased urge to urinate
• Discomfort in your lower abdominal region

3. Eye symptoms

You may experience inflammation in your eyes (conjunctivitis) and other symptoms which include the following:

• Redness in the eyes
• Excessive tearing or watery eyes
• Eye discomfort or pain
• Swelling of the eyelids
• Increased sensitivity to light

4. Other symptoms

Reactive arthritis can cause several other symptoms, such as the following:

• Fever
• Weight loss
• Ulcers in the mouth
• Rashes on hands or feet

Causes of reactive arthritis

Here are some of the common causes that can lead to reactive arthritis–

1. Gastrointestinal infections

Reactive arthritis often follows an infection, typically caused by certain bacteria. The most common infections associated with reactive arthritis include Salmonella, Shigella, and Campylobacter (foodborne infections). It is believed that the immune response triggered by the infection may mistakenly target healthy joint tissues.¹

2. Genitourinary infections

Infections in the genital or urinary tract, particularly with Chlamydia trachomatis, can lead to reactive arthritis. Chlamydia-induced reactive arthritis is one of the most well-known forms of the condition.¹

3. Respiratory infections

Some cases of reactive arthritis have been associated with respiratory infections, including those caused by Mycoplasma pneumonia.²

4. Other infections

While gastrointestinal and genitourinary infections are the most common triggers, reactive arthritis can also occur in response to other infections like HIV, Yersinia, and Clostridium difficile.¹

5. Genetic factors

Some individuals may be genetically predisposed to developing reactive arthritis, and the presence of certain genes, such as HLA-B27, has been linked to an increased risk.³

6. Environmental factors

Certain environmental factors, such as smoking, alcohol, vitamin D, protein and red meat, breastfeeding and geography, may affect the likelihood of developing reactive arthritis in some individuals.⁴

It's essential to note that if you develop symptoms suggestive of reactive arthritis, you should seek medical evaluation and treatment, as the condition can cause joint inflammation and other symptoms that may require management.

Risk factors of reactive arthritis

The risk factors involved in reactive arthritis include the following:

1. Gender

The likelihood of developing reactive arthritis in response to foodborne infections is approximately equal in both people assigned female and male at birth (AFAB and AMAB). However, when it comes to reactive arthritis triggered by sexually transmitted bacteria, AMAB has a higher likelihood of developing the condition compared to AFAB.

2. Age

Reactive arthritis is more common in young to middle-aged adults, with the highest risk in individuals aged 20 to 40. 

3. Genetic factors

The presence of the HLA-B27 gene is strongly associated with an increased risk of reactive arthritis. However, not everyone with HLA-B27 develops reactive arthritis, and not everyone with reactive arthritis has this gene.³

4. HIV infection

The presence of AIDS or an HIV infection elevates the risk of developing reactive arthritis.³

Diagnosis of reactive arthritis

The diagnosis of reactive arthritis typically involves a combination of clinical evaluation, laboratory tests, imaging studies, and consideration of a differential diagnosis. 

1. Physical examination

Physical examination involves a detailed assessment of the patient's medical history, including any recent infections and a physical examination to identify signs and symptoms. In reactive arthritis, patients often present with symptoms such as joint pain, swelling, and stiffness, as well as inflammation in other parts of the body, like the eyes, skin, or genitourinary system.

1. Laboratory tests

Laboratory tests are essential in the diagnosis of reactive arthritis. Common tests may include the following:

• Blood tests may reveal signs of inflammation, such as elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels.³
• Serologic tests for certain antibodies, such as HLA-B27, may be performed. HLA-B27 is often associated with reactive arthritis and other spondyloarthritis conditions.
• Microbiological tests identify the presence of the triggering infection, and tests for specific microorganisms (e.g., Chlamydia, Salmonella, Shigella, Yersinia, or Campylobacter) may be conducted, depending on the clinical history.³

1. Imaging tests

Imaging studies are used to assess joint and soft tissue involvement and can help rule out other conditions and monitor the progression of the disease. These studies can include the following:

• X-rays can reveal signs of joint damage or inflammation.
• Ultrasounds can be useful for evaluating soft tissue and joint inflammation.
• An MRI can provide detailed images of joints and surrounding structures.

1. Differential diagnosis

Differential diagnosis is crucial to distinguish reactive arthritis from other conditions that share similar symptoms. Conditions that may need to be ruled out include other types of arthritis (e.g., rheumatoid arthritis, ankylosing spondylitis), infections, and inflammatory diseases.³

Consulting with a healthcare professional is crucial for an accurate diagnosis and appropriate management.

Treatment of reactive arthritis

Below are the treatment options for reactive arthritis:

Medications

• Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) such as ibuprofen and indomethacin can help reduce pain and inflammation associated with reactive arthritis.⁵
• Antibiotics can help in the treatment of reactive arthritis as well as for any underlying bacterial infection.³
• Disease-modifying antirheumatic drugs (DMARDs) like sulfasalazine or methotrexate may be prescribed to help slow down the progression of the disease and reduce joint damage.³
• Biologic therapies such as biologic drugs like tumour necrosis factor (TNF) inhibitors, such as etanercept or adalimumab, may be considered for individuals with severe symptoms and who do not respond well to other treatments.³

Physical therapy

Physical therapy can help improve joint mobility and strength, reduce pain, and enhance overall function. Exercises and stretches tailored to the affected joints can be beneficial.

Management of underlying infections

Since reactive arthritis often occurs as a reaction to a preceding infection, it's important to treat any underlying infections. This may involve antibiotics in the case of bacterial infections or antiviral medications if the condition is triggered by a viral infection.¹

It's crucial to consult with a healthcare professional, such as a rheumatologist, to determine the most appropriate treatment plan for your specific case of reactive arthritis. 

Prevention of reactive arthritis

Below are some of the steps you can take to prevent yourself from reactive arthritis:

Practice safe sex

Some cases of reactive arthritis are linked to sexually transmitted infections, such as Chlamydia. Practising safe sex can reduce the risk of contracting these infections.

Maintain good hygiene

Proper hygiene can help prevent various infections that could trigger reactive arthritis.

Prompt treatment of infections

If you suspect you have an infection, seek prompt medical treatment. Timely and effective treatment of infections can help prevent the development of reactive arthritis.

Avoiding food and water contamination

In some cases, reactive arthritis can be associated with food and waterborne infections. Be cautious when consuming or handling food and water to reduce the risk of infection.

Summary

Reactive arthritis is an autoimmune condition that typically develops in response to an infection, often involving the urinary or gastrointestinal systems. It is characterized by joint pain, swelling, and inflammation, particularly in the lower extremities. Other common symptoms include eye inflammation (conjunctivitis), skin rashes, and urethritis. Reactive arthritis is thought to be triggered by the body's immune response to an infection, leading to inflammation in multiple body systems. Treatment may involve managing symptoms with medications and addressing the underlying infection, if present. Early diagnosis and treatment can help alleviate discomfort and prevent long-term complications.