Reactive arthritis refers to pain, stiffness, redness or swelling in a joint resulting from a previous infection. This disease most often occurs in the joints of the lower limbs (knees, ankles, toes), but can also affect the upper limbs. Problems can occur only in the joints Treatment and Prevention or affect other organs, such as the eyes, skin, muscles or tendons.
If you have reactive arthritis, you will likely experience the warning signs within weeks of an infection, such as food poisoning or other bowel disease. It can also be chlamydia, a disease transmitted by an infected person during sex. (It is important to note that even if the infection in question is transmissible, reactive arthritis itself cannot be transmitted from one person to another.)
Signs of the disease include stiffness, pain and swelling in a joint for no apparent reason. Additionally, the affected area may be red and hot to the touch. The pain and stiffness may be more intense in the morning. Usually the disease only attacks one joint at first, but other joints can be affected over time.
Most often, inflammation occurs in the lower extremities (knees, ankles, toes). You may also experience lower back pain if the condition affects your sacroiliac joints – the joints at the base of the spine where it connects to the pelvis. If joint problems persist, you may experience stiffness in the joints and muscle weakness, as well as difficulty in fully straightening these joints.
Problems can also occur in other parts of the body, such as tendons, skin, and eyes. Some people experience pain in the heel, where the Achilles tendon attaches to the bone, or under the foot, where the tendons that support the arch of the foot attach to the heel. The eyes could also be sore or sensitive to sunlight. The mouth or genitals may have sores, painful or painless. (Inflammation associated with reactive arthritis occurring at any of these sites was formerly called Reiter’s syndrome).
How is reactive arthritis diagnosed?
Establishing an accurate diagnosis is important. If your doctor suspects you have reactive arthritis, he or she will ask you questions to get the full picture: symptoms, other health conditions, recent travel, illnesses, and contact with people who may carry infections. Since there is usually a lag of several days or weeks between infection due to arthritis and the onset of inflammation, people do not always connect the two events and may not think of mentioning the ‘infection. Your doctor may also do a physical exam, X-rays, and other tests to determine the cause of your arthritis.
Diagnosis can be difficult because there is no specific test to confirm the presence of reactive arthritis. Your doctor will examine you and likely do other tests, such as X-rays and blood tests. One of these tests, called ESR (sedimentation rate), measures the degree of inflammation in the blood. This is often elevated in people with reactive arthritis. If you have reactive arthritis, you may also have anemia, a blood disorder that causes paleness, weakness, numbness and dizziness.
Your doctor may also order tests of your stool or the fluids and tissues of your urethra or joints. About half of patients with reactive arthritis test positive for HLA-B27. This genetic marker is often found in people who have a form of inflammatory arthritis in the category of spondyloarthropathy, a group of diseases that includes reactive arthritis. This could indicate a genetic predisposition to these forms of inflammatory arthritis, but the presence of the gene alone does not diagnose reactive arthritis.
What are the risk factors for reactive arthritis?
Certain types of bacteria cause reactive arthritis. If you have reactive arthritis, one of them may have already made you sick. The bacteria that cause reactive arthritis are among those that cause food poisoning with subsequent diarrhea, namely salmonella, shigella, campylobacter and yersinia.
Sexually transmitted infections, such as chlamydia, can also cause reactive arthritis. After making you sick, the bacteria can migrate to other parts of the body, where they can cause inflammation. Reactive arthritis cannot be passed from one person to another.
Anyone susceptible to food poisoning can also develop reactive arthritis. However, this disease usually affects people who are between 20 and 50 years old.
