Reactive Arthritis

Reactive arthritis is a type of joint pain and swelling. It happens when an infection in another part of your body, like your intestines, genitals, or urinary tract, triggers inflammation in your joints.

This inflammation often affects the knees, ankles, and feet. But it can also impact your eyes, skin, and the tube that carries urine out of your body (urethra). In the past, this condition was sometimes called Reiter's syndrome.

Reactive arthritis isn't very common. For many people, the pain and swelling will come and go, and usually disappear within a year.

Reactive arthritis usually shows up 1 to 4 weeks after an infection. This means your body's immune system is reacting to a bug, not the joint itself. Here are some common signs and symptoms:

Joint Pain and Stiffness: The most common places to feel pain are your knees, ankles, and feet. But you might also have pain in your heels, lower back, or buttocks. The pain can make it hard to move those parts of your body.

Eye Problems: Many people with reactive arthritis get eye inflammation, which is like having pink eye (conjunctivitis). It can cause redness and irritation in the eyes.

Urinary Problems: You might urinate more often than usual and feel discomfort. Sometimes, there's inflammation in the prostate (in men) or the cervix (in women).

Inflammation at the Joints: This happens where tendons and ligaments connect to bones (called enthesitis). It's most often found in the heels and bottom of the feet. This inflammation can cause pain and swelling.

Swollen Fingers and Toes: Sometimes, your toes or fingers swell up, making them look like sausages. This is another sign of inflammation.

Skin Problems: Reactive arthritis can affect the skin in different ways. You might have mouth sores, or a rash on the soles of your feet or palms of your hands.

Back Pain: You might feel more pain in your lower back, especially in the morning or at night. This is likely because the inflammation is worse when your body is at rest.

If you have joint pain starting soon after having diarrhea or a sexually transmitted infection (STI), talk to your doctor. This could be a sign of a condition that needs medical attention. It's important to see a doctor promptly so they can figure out what's causing the pain and recommend the best treatment.

Reactive arthritis happens when your body reacts to an infection, often in your gut, genitals, or urinary system. Sometimes the initial infection is very mild or doesn't cause any noticeable symptoms at all, so you might not even know it's there.

Several types of bacteria can trigger this reaction. Some are spread through sexual contact, and others can be found in contaminated food. Common examples include:

• Campylobacter: A bacteria often found in undercooked poultry or contaminated water.
• Chlamydia: A sexually transmitted infection (STI).
• Clostridioides difficile (C. diff): A bacteria that can cause diarrhea, often associated with antibiotic use.
• Escherichia coli (E. coli): A bacteria that can cause food poisoning, often linked to contaminated food or water.
• Salmonella: A bacteria that can cause food poisoning, commonly found in raw or undercooked eggs, poultry, and meat.
• Shigella: A bacteria that causes severe diarrhea, often spread through contaminated food or water.
• Yersinia: A bacteria that can cause food poisoning, often found in contaminated food.

Important Note: Reactive arthritis itself isn't contagious. You can't catch it from another person. However, the bacteria that cause reactive arthritis can be spread through sexual contact or by eating contaminated food. Only a small percentage of people exposed to these bacteria will actually develop reactive arthritis. This means your immune system plays a crucial role in how your body reacts to these infections.

Reactive arthritis is a condition where the body's immune system mistakenly attacks healthy tissues. Several things can make you more prone to getting it.

• Your age: Most people who develop reactive arthritis are between 20 and 40 years old.

• Your sex: Men and women are equally likely to get reactive arthritis if it's triggered by food poisoning. But if the cause is a sexually transmitted infection, men are more likely to get it than women. This is important because the type of infection can influence who is at risk.

• Family history: Some people have a genetic marker that's been linked to reactive arthritis. However, even if you have this marker, it doesn't guarantee you'll get the condition. Many people with this marker never develop reactive arthritis. It means that genetics play a role, but other factors are also important.

Your genes might influence whether you get reactive arthritis. While you can't alter your genes, you can take steps to lower your risk of getting the bacteria that often cause this condition.

One way to do this is to keep food properly stored and cooked. Many bacteria that cause reactive arthritis are foodborne. These include, for example, salmonella, shigella, yersinia, and campylobacter. Making sure your food is handled and cooked safely can significantly reduce your chances of getting these bacteria.

Another way to reduce your risk is by practicing safe sex. Some sexually transmitted infections (STIs) can trigger reactive arthritis. Using condoms can help lower your risk of getting these infections.

To diagnose reactive arthritis, your doctor will perform a physical exam. This often involves checking your joints for swelling, warmth, and tenderness. They'll also assess how well you can move your spine and affected joints. Your doctor might also look at your eyes for inflammation and your skin for any rashes.

Your doctor may order some blood tests to help find out what's going on. These tests can look for:

• Evidence of past or current infections: This helps determine if an infection might be causing the arthritis.
• Signs of inflammation: Inflammation is a common feature of arthritis.
• Antibodies associated with other types of arthritis: This helps distinguish reactive arthritis from other conditions.
• A genetic marker linked to reactive arthritis: Some people have a genetic predisposition to this condition.

Your doctor might also take a small sample of fluid from the affected joint. This fluid will be examined to check for:

• White blood cell count: A higher-than-normal white blood cell count could suggest inflammation or an infection.
• Infections: Bacteria in the joint fluid could indicate a serious infection called septic arthritis, which can severely damage the joint. This is a crucial finding because it needs immediate treatment.
• Crystals: Uric acid crystals in the fluid might point to gout. Gout is a type of arthritis that often affects the big toe first, causing significant pain.

Finally, X-rays of your lower back, pelvis, and affected joints can help reveal characteristic signs of reactive arthritis. X-rays can also help rule out other types of arthritis. This helps your doctor make an accurate diagnosis.