What is reactive arthritis?
Reactive arthritis is a type of arthritis in which the joints become painful and swollen after an infection. The infection might have been in the intestines, genitals, or the urinary tract.
Who gets reactive arthritis?
It most commonly affects men aged between 20 and 40. This is because they are most at risk of urethral infection from sexually transmitted diseases. However, it can occur at any age and in anyone. We are all at risk of getting a gut infection from food poisoning that may trigger a reactive arthritis. About 1 in 10 people in the world have a gene called HLA-B27. About three out of four people who have reactive arthritis have this gene. So, this gene seems to make you more likely to develop reactive arthritis if you have a ‘triggering’ infection.
What Causes Reactive Arthritis?
Reactive arthritis typically begins about 1 to 3 weeks after infection. The bacterium most often associated with reactive arthritis is Chlamydia trachomatis. It is usually acquired through sexual contact. Infections in the digestive tract that may trigger reactive arthritis include Salmonella, Shigella, Yersinia, and Campylobacter. People may become infected with these bacteria after eating or handling improperly prepared food, such as meats that are not stored at the proper temperature.
Approximately 80% of people with reactive arthritis test positive for HLA-B27. However, inheriting the HLA-B27 gene does not necessarily mean you will get reactive arthritis. Eight percent of healthy people have the HLA-B27 gene, and only about one-fifth of them will develop reactive arthritis if they contract the triggering infections.
What Are the Symptoms of Reactive Arthritis?
- Reactive arthritis often affects the urogenital tract, including the prostate or urethra in men and the urethra, uterus, or vagina in women. Men may notice an increased need to urinate, a burning sensation when urinating, and a fluid discharge from the penis. Some men with reactive arthritis develop prostatitis. Symptoms of prostatitis can include fever and chills, as well as an increased need to urinate and a burning sensation when urinating.
- Women with reactive arthritis may develop problems in the urogenital tract, such as cervicitis (inflammation of the cervix) or urethritis (inflammation of the urethra), which can cause a burning sensation during urination. In addition, some women also develop salpingitis (inflammation of the fallopian tubes) or vulvovaginitis (inflammation of the vulva and vagina). These conditions may or may not cause any arthritic symptoms.
- The arthritis associated with reactive arthritis typically involves pain and swelling in the knees, ankles, and feet. Wrists, fingers, and other joints are affected less often. People with reactive arthritis commonly develop inflammation of the tendons or at places where tendons attach to the bone (ethesitis). In many people with reactive arthritis, this results in heel pain or irritation of the Achilles tendon at the back of the ankle.
- Reactive arthritis also can cause spondylitis (inflammation of the vertebrae in the spinal column) or sacroiliitis (inflammation of the joints in the lower back that connect the spine to the pelvis).
- Conjunctivitis, an inflammation of the mucous membrane that covers the eyeball and eyelid, develops in approximately half of people with reactive arthritis. Some people may develop uveitis, which is an inflammation of the inner eye. Conjunctivitis and uveitis can cause redness of the eyes, eye pain and irritation, and blurred vision.
- Between 20-40% of men with reactive arthritis develop small, shallow, painless sores (ulcers) on the end of the penis. A small percentage of men and women develop rashes or small, hard nodules on the soles of the feet and, less often, on the palms of their hands or elsewhere.
How do we diagnose reactive arthritis?
The most reliable way to diagnose reactive arthritis is to identify the bacterial trigger in the stool or urine. Blood tests may be helpful but are not as specific as identifying the bacteria in the stool or urine.
What is the treatment for reactive arthritis?
- If the trigger is an infection of the urethra, a short course of antibiotics will usually be advised.
- Gut infections have often cleared on their own by the time the reactive arthritis develops. But, if a stool sample shows that a germ is still present then treatment may be advised to clear it.
- Anti-inflammatory painkillers ease pain and stiffness.
- An injection of steroid medicine directly into a joint is an option if it becomes badly inflamed.
- Physiotherapy helps to keep the joints moving. It also helps to keep the muscles around affected joints strong if you are not using a joint very much.
If symptoms persist for more than a few months, or if other treatments have not worked, then you may be advised to take a ‘disease-modifying’ medicine. These aim to reduce the damaging effect on the joints.