Reactive Arthritis

Reactive arthritis refers to the inflammation, pain, and swelling in the joints that follows an infection in other parts of the body, particularly infection of the gut or urinary system. The eyes and the urethra also get affected, along with the joints. It was previously known as reiter’s syndrome and harbored an autoimmune etiology. This condition is not very common and resolves by itself. In some cases, it may take up to 12 months to fully recover. 

Reactive arthritis occurs after an infection of the gastrointestinal tract (food poisoning) or genitourinary system (UTI or STD). The most common organism found to be implicated in reactive arthritis is Campylobacter (C. jejuni). Other organisms include Shigella, Salmonella, and Chlamydia trachomatis (genitourinary infections). When these infections are near resolving, reactive arthritis develops due to cross-reactivity between bacterial antigens and body tissues. This mechanism is called autoimmunity when the body's defense system mistakenly attacks its tissues, assuming they are bacteria. 

It causes 3.5-5 cases per 100,000 population in the USA. The following factors may increase your chances of reactive arthritis.

·         Age: It is most prevalent in the third decade of life (20-40 years of age).

·         Gender: Men are more commonly affected.

·         Race: It is found more in white people.

·         Genetics: It is found to be associated with a special genetic marker, HLA-B27. People with this genome are affected more.

·         HIV: People with HIV are at high risk of developing reactive arthritis.

The classical presentation of reactive arthritis is a triad of symptoms;

·         Conjunctivitis

·         Urethritis (nongonococcal)

·         Oligoarthritis (asymmetric)

The symptoms may appear after one to three weeks of the inciting infection.

Urethritis: This is an infection of the urethra, and sometimes the cervix may also be involved in females. It causes burning pain of passing urine and an increased need to urinate.

Arthritis: It causes pain and swelling in the large joints (knee joint and sacroiliac joint).

Conjunctivitis and uveitis: These are infections of eye tissues. They cause red and painful eyes and blurring of vision.

Other features:

Tendinitis: Some people may have pain in the heels due to inflammation of the Achilles tendon or plantar fascia. These tissues are present in your lower legs and feet.

Nodules: Some people develop nodules on palms and soles called keratoderma blennorrhagicum.

Penile lesions: A few men develop penile lesions along the length of the penis, called balanitis circinata.

Dactylitis: It is the diffuse swelling of the finger and is also known as the sausage finger.

Mucocutaneous lesions: Some people develop ulcers, inflammation around the mouth, anus, or symptoms like Crohn's disease. 

If you feel that you are having the symptoms of reactive arthritis, you need to consult your healthcare provider. Your doctor will ask you questions regarding your current symptoms, previous history, and any infection of the gut or urethra in the last few days. Then your doctor will perform a physical examination focusing on the joints. He will check for swelling, pain, and range of motion. He may advise you to undergo the following tests to confirm the diagnosis. These tests are not specific for reactive arthritis, but they will help to rule out other possible causes.

• Blood tests: ESR and CRP tests may be advised, the increase of which points towards inflammation. Rheumatoid factor (inflammatory proteins) and CCP antibody tests may also be performed, which will be negative in the case of reactive arthritis. A genetic test for the evaluation of HLA-B27 can be performed.
• Imaging tests: X-rays can show disease activity in the joints. It can show decreased joint space due to fusion of the bones or increased joint space due to the destruction of the bony structures. Soft tissue swelling can be seen too. An MRI scan can be ordered to get a more clear picture.  

Synovial Joint fluid analysis: Synovial fluid is the fluid in the joint cavity that is aspirated through a big needle and sent to the lab for analysis of different parameters that can help in developing diagnosis. In reactive arthritis, no bacteria will be found in the fluid, pointing toward an autoimmune etiology.

Many disorders can look like reactive arthritis due to the involvement of the joints, eyes, and urinary system.

·         Conjunctivitis

·         Scleritis

·         Iritis and Uveitis

·         Glaucoma

·         Gout and Pseudogout

·         Psoriasis

·         Juvenile Rheumatoid Arthritis

·         HLA-B27 Syndromes

·         Cervicitis

·         Crohn Disease

·         Inflammatory Bowel Disease

·         Behçet Disease

·         Sarcoidosis

·         Tendonitis

·         Tenosynovitis

·         Tick-Borne Diseases

·         Lyme Disease

There is no specific treatment for reactive arthritis. If the inciting infection is still present, the doctor will give antibiotics to eradicate it. Otherwise, all the treatment is directed towards relieving the symptoms. Along with these, you would be asked to adopt some lifestyle changes to help you tackle the disease, like doing simple exercises and consuming anti-oxidant and omega-3 fatty-acids-rich food. The following medications can be given;

Pain-relieving medicines: Paracetamol, NSAIDs, and celecoxib can be prescribed

Anti-inflammatory medicines: NSAIDs also reduce inflammation but have side effects. Steroids are used in low doses to control inflammation before the commencement of disease-modifying agents.

Disease-modifying agents (DMARDs): These are the group of agents that slow the progression of the disease, improve pain, and prevent damage. They include methotrexate, sulfasalazine, hydroxychloroquine, TNF alpha inhibitors (infliximab, etanercept), monoclonal antibodies (rituximab)

Physical therapy: It may be advised to improve muscle activity and reduce pain. 

Reactive arthritis may take different courses. It may resolve on its own or may take a relapsing and remitting course. In a few patients, it can be progressive or chronic. However, most people can have a normal life with regular treatment and care. 

You can take some measures to prevent the development of the disease;

·         Use condoms for safe sex to avoid transmission of STDs.

·         Eat food that is properly cooked and stored to prevent gut infections.

The disease progression and severity can be controlled by adopting some changes in lifestyle;

·         Gentle exercises can have a good impact on your joint mobility

·         Consuming foods rich in omega-3 fatty acids (walnuts, chia seeds, fish), anti-oxidants (berries, kidney beans, spinach)

• Taking rest and applying cold/hot patches on inflamed joints