What is Reiter Syndrome

Reactive arthritis

What is reactive arthritis?

Reactive arthritis (ReA) is a rare inflammatory disease of the joints that occurs in response to an infection in another part of the body. It is sometimes referred to as Reiter's syndrome, Reiter's disease, or Reiter's arthritis.

However, these terms only describe a small group of people who live with ReA. The condition is more likely to occur in young adults and more common in men than women.

The initial infection is caused by certain groups of bacteria that affect the gastrointestinal tract or urinary system. Arthritis develops after a period of time that can (typically) last days to weeks. In most cases, it affects only one or a few joints in the legs.

The diagnosis depends on the typical symptoms, clinical findings, disease progression, and the exclusion of other causes of arthritis. Initial treatment consists of nonsteroidal anti-inflammatory drugs (NSAIDs).

Reactive arthritis can vary in severity and usually occurs as an isolated disease with no other symptoms and a good prognosis. However, some people may experience persistent symptoms. [1],[2],[3],[4],[5]

If you think you may have reactive arthritis, you can try using Ada to find out more about your symptoms.

What are the causes of reactive arthritis?

Reactive arthritis (ReA) is an inflammatory disease of the joints that occurs in response to an infection in another part of the body.

Typically reactive arthritis will either caused by bacteria causing a urinary tract infection or sexually transmitted disease such as chlamydia, or by bacteria that cause gastroenteritis, also known as food poisoning - such as Campylobacter. The offending infection may have been so weak that it was not noticed.

ReA is not an infection of the joints and the severity of the initial infection is not related to the severity of the resulting arthritis.

It is not clear why these exact symptoms develop beyond the areas of the body that were or are still infected. Reactive arthritis is believed to be an autoimmune disease in which the body makes antibodies that attack healthy tissue and cause inflammation.[3],[6],[4]

Risk factors

Reactive arthritis (ReA) is always caused by an infection in another part of the body. The most common infections that cause reactive arthritis are:[3],[5]


  • an infection of the urethra, the tube that carries urine out of the bladder
  • is often caused by a sexually transmitted infection (STI), most commonly chlamydia.

Gastrointestinal infection

  • Infection of the intestines, often due to food poisoning
  • certain groups of bacteria, such as Shigella, Salmonella, Campylobacter, and Yersinia

Chlamydophila pneumoniae

  • Bacteria that can cause pneumonia

Other infections

It is not entirely clear why someone develops ReA in response to infection. Certain factors that are more common in those affected include:[1],[3],[7],[8]

  • at the age of approx. 20 to 40 years,
  • male,
  • Carrier of the HLA-B27 gene,
  • HIV positive.

What are the symptoms of reactive arthritis?

Musculoskeletal complaints:


  • acute symptoms,
  • only one or a few joints affected,
  • asymmetrical,
  • often the lower extremities, especially the knees, are affected.


  • inflammation where the bone connects to ligaments, tendons, or other connective tissue;
  • Pain, swelling and local tenderness;
  • mostly on the back of the heel or the sole of the foot.


  • Swelling of the fingers - which look like sausages

Lower back pain

Additional symptoms include:

  • itchy, red eyes known as conjunctivitis
  • painful urination due to a urinary tract infection
  • genital discharge caused by a sexually transmitted disease
  • diarrhea caused by gastrointestinal infection
  • painless ulcers in the mouth
  • scaly rash on the palms of the hands or the soles of the feet
  • Changes in the nails
  • painful rash on the end of the penis known as balanitis
  • possibly weight loss and fever

None of the above symptoms alone are typical of reactive arthritis. The combination of painful urination, conjunctivitis, and arthritis is sometimes referred to as Reiter's syndrome. Only one in three people who live with reactive arthritis will have all of these symptoms.[1]

If you think you may have reactive arthritis, you can try using Ada to find out more about your symptoms.

How is reactive arthritis diagnosed?

The diagnosis is generally made after a referral to a rheumatologist, a doctor who specializes in inflammation and pain in the joints, muscles, or connective tissues.

Unlike other forms of arthritis, there is no specific test that can detect reactive arthritis. Instead, a rheumatologist needs to gather information to rule out other conditions and determine the cause of a patient's symptoms.[1],[3],[9]

The three cornerstones of diagnosis are:

  1. The typical musculoskeletal symptoms (see above)

  2. A history of urinary tract disease or pre-arthritis diarrhea

  • may not have been noticed
  • The underlying germ can only be identified in every second person with ReA (this is therefore not necessary for establishing a diagnosis)
  • other infections are also possible, although less common
  1. Exclusion of other forms of arthritis
    • decisive for the diagnosis.[3]

To make the diagnosis, the doctor will ask for the following information:


  • Are there any recent or ongoing infections?
  • Are there joint pain and other musculoskeletal symptoms?
  • Where? how long? Etc.

Physical examination

  • swollen joints, swollen fingers and toes and / or pain-sensitive areas?
  • inflammation of the skin or eyes?
  • any symptoms of a sexually transmitted disease? (see above)

Laboratory tests

Routine blood test in the laboratory

Analysis of the blood for signs of acute inflammation or certain systemic diseases.

  • complete blood count

  • Acute phase proteins

    • Erythrocyte sedimentation rate (ESR)
    • C-reactive protein (CRP)
  • Kidney and liver function

HLA-B27 test

  • People who have this gene are more likely to develop reactive arthritis.
  • The gene can be detected with a blood test.
  • However, only 30 to 50 percent of people with ReA are carriers of the gene.
  • It is therefore not necessarily typical of reactive arthritis.

Serological diagnostics for rheumatoid arthritis

Examination of the blood for:

  • Rheumatoid factor

    • Antibodies against citrullinated proteins
    • present only in people with arthritis in multiple joints
  • These antibodies are usually absent in people with ReA.

Joint puncture

  • a hypodermic needle is used to pull the fluid out of the affected joint.
  • is performed when the joint is swollen
  • you can tell if a joint is infected by counting the number of white blood cells and analyzing the bacteria
  • can rule out septic arthritis

Stool samples

  • Analysis of the stool for specific groups of bacteria
  • occurs when the person concerned has diarrhea

Urine sample

  • The urine will be examined for signs of a urinary tract infection.

  • In some cases, the first few drops of urine must be collected specifically for this

    • Is done if: - Chlamydia trachomatis is suspected - The patient does not have diarrhea or symptoms typical of a urinary tract infection or a sexually transmitted disease.

Vaginal smear

  • is carried out when:
    • you suspect an infection with Chlamydia trachomatis
    • The patient does not have diarrhea or symptoms typical of a urinary tract infection or an STD.

Medical imaging

  • X-rays of the affected joints and tendons (connection between bone and soft tissue)
  • Is done to detect changes in the joint.
  • May be needed to rule out other causes of joint pain, such as certain forms of arthritis and stress fractures.[3],[10],[11],[4],[12]

How is reactive arthritis treated?

Treatment for reactive arthritis can vary based on the underlying infection that started the disease in the first place. In addition, the treatment can vary depending on the symptoms and the response of the person concerned to the initial medication.[1],[3],[4],[5]

Treatment generally includes the following three points:[3]

  • Treating the infection
  • Treatment of arthritis
  • Treatment of the remaining symptoms.

Treating the infection

Some people with ReA stop taking Antibiotics to treat the underlying infectionthat caused the disease is necessary.

This can be the case if:

  • you currently have a urinary tract infection or a sexually transmitted disease,

    • especially when chlamydia is the trigger.
  • you currently have a gastrointestinal disease that,

    • caused by certain types of bacteria,
    • is serious
    • affects an old person or a person with a weakened immune system.

It does not make sense to take it if:

  • the underlying gastrointestinal disease has resolved,
  • she is mild,
  • it was caused by a virus.

It is generally not recommended to take antibiotics unless there is a valid reason to do so.[3],[5]

Treatment of arthritis

Treatment for arthritis itself is aimed at reducing inflammation and suppressing the body's autoimmune response. There are two stages:

  • Treatment of acute ReA,

  • Treatment of chronic ReA

    • Has existed for six months or more,
    • no response to previous treatments.[1],[3],[5]

Treatment of acute ReA

Fortunately, in most cases reactive arthritis will go away on its own and will not destroy the joint. Therefore, the aim of therapy is to alleviate the symptoms.

The introductory treatment consists of:

  • nonsteroidal anti-inflammatory drugs (NSAIDs), such as diclofenac

    • The blood count and liver and kidney function should be checked before and during treatment.
  • Glucocorticoids

    • given either as a tablet or directly into the affected joint
    • This is only required for people who have not responded to NSAIDs.

Treatment of chronic ReA

If the ReA lasts six months or more and has not responded to previous treatment, it is considered chronic. A specialist decides how to proceed.

Treatment of the remaining symptoms

People with ReA who have symptoms affecting the eyes, mouth, or skin may need additional therapy. In these cases, a specialist should be consulted who will assess the severity and need for treatment.

Can reactive arthritis be prevented?

This depends on the underlying infection that triggered the reactive arthritis. If it is a urinary tract infection or a venereal disease caused by chlamydia, antibiotic treatment of the acute infection can prevent ReA from developing. There is no evidence that antibiotic treatment can prevent ReA resulting from gastroenteritis or chronic ReA.[5]

What is the prognosis for reactive arthritis?

The course of the disease can vary from person to person. In about half of all people with ReA, symptoms resolve within six months. However, in some people the condition can persist and become chronic.[3],[4]

It can recur in people who have the HLA-B27 gene.[1]

What are the complications of reactive arthritis?

In some patients, arthritis can be persistent too Joint damage to lead. Consultation with a specialist, especially in the case of chronic diseases, is strongly recommended.

If you think you may have reactive arthritis, you can try using Ada to find out more about your symptoms.

  1. ANVIL. "Reactive Arthritis." - As of October 01, 2019 ↩↩↩↩↩↩↩

  2. Versus arthritis. "Reactive arthritis?" - As of October 02, 2019 ↩

  3. UpToDate. "Reactive arthritis." - As of October 01, 2019 ↩↩↩↩↩↩↩↩↩↩↩↩

  4. BMJ Best Practice. "Reactive arthritis." - As of October 02, 2019 ↩↩↩↩↩

  5. Medscape. "Reactive Arthritis." - As of October 02, 2019 ↩↩↩↩↩↩

  6. Harvard Health. "Reactive Arthritis." - As of October 02, 2019 ↩

  7. NHS inform. "Reactive arthritis - Illnesses & conditions." - As of October 02, 2019 ↩

  8. NCBI - NIH. "Modes of Presentation of Reactive Arthritis Based on the Affected Joints." - As of October 02, 2019 ↩

  9. Stanford Health Care. "Reactive Arthritis Diagnosis." - As of October 02, 2019 ↩

  10. Arthritis-health. "What Is Arthrocentesis?" - As of October 02, 2019 ↩

  11. MedicineNet. "Reactive Arthritis Treatment, Symptoms, Causes." - As of October 02, 2019 ↩

  12. NORD (National Organization for Rare Disorders). "Reactive Arthritis." - As of October 02, 2019 ↩