Reactive Arthritis: Post-infectious Inflammation, Joint Pain and Other Symptoms

Reactive Arthritis: Post-infectious Inflammation, Joint Pain and Other Symptoms
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Reactive arthritis is a term for an inflammatory disease of the joints that develops in response to an infection in another part of the body.


Reactive arthritis is an inflammatory disease of the joints that results from recovering from an infection in another part of the human body.

It develops with a certain time delay when signs and symptoms of the initial infection may no longer be present. This most often happens after infections of the gastrointestinal (digestive) and urogenital systems, but also after respiratory tract infections.

The course of the disease is usually acute, but sometimes turns chronic and does not leave any serious joint damage behind. It is common for joint problems to be accompanied by extra-articular problems, the most common of which is inflammation of the eye and conjunctiva.

It mostly affects people between the ages of 20 and 40, but it also occurs in children and the elderly.

The disease is reported to affect about the same number of men and women, but in some cases, there is a higher incidence in men. These are mainly cases of urogenital post-infectious arthritis.

Arthritis, an inflammation affecting the synovial layer of the joint, or
synovitis = inflammation of the synovial membrane. 

Wondering why some people develop the disease after a certain infection and others don't?

The exact cause is unknown.

However, there may be a connection with the presence of the HLA B27 antigen, which is positive in some people.

In that case, the risk is said to increase 10 to 20 times.

Want to know more about reactive arthritis?
What infections cause them?
How do they manifest themselves?
Can it be treated?
Read on and learn more. 

Let's Define Reactive Arthritis

Reactive arthritis is a sterile inflammation of the joints that has developed over a specific time period based on recovery form an infection in another part of the human body. However, the individual has an increased genetic predisposition to the development of the diseases.

A more technical definition would be:

Immune-related synovitis, which develops due to the presence of an antigen, nucleic acids or disrupted forms of an inducing microorganism in the joint (viable microorganisms that are not proven by culture).

Reactive arthritis, in which there is a triad of symptoms,
i.e. joint involvement, inflammation of the urinary tract and inflammation of the conjunctiva, formerly known as Reiter's syndrome. 

The disease belongs to a form of spondylarthritis, as it shares some common features and manifestations, such as:

  • presence of HLA antigen
  • involvement of the axial skeleton - spine + sacroiliac joints - connections between the pelvis and spine
  • more frequent inflammation of the eyes and conjunctiva
  • frequent inflammation of tendons and their attachments
  • skin complications and mucosal involvement
  • increase in erythrocite sedimentation rate (FW) and C-reactive protein (CRP)

Spondyloarthropathies (diseases with concomitant spinal cord injury) include psoriatic arthritis and ankylosing spondylitis.

The presence of HLA B27 increases the risk of these diseases.
Its absence does not preclude the development of arthritis.

Reactive arthritis is typical in that it lasts for several weeks, but then subsides. They do not leave permanent structural damage to the joints.

They rarely go into a chronic course.

Even in the case of this disease, its early detection and timely treatment are important.


The exact cause of reactive arthritis is unknown.

However, the presence of HLA B27 antigens, which are among the major predisposing factors, is involved in its development. At the same time, however, their absence does not exclude a possible outbreak.

However, they increase the risk 10 to 20 times.

Family history is therefore possible, but there is no direct inheritance.

It is based on a diseased immune response when the body's immunity attacks the body's own cells. So it has an autoimmune component.

This body's defenses have been altered after a previous infection with a particular pathogen.

Bacteria or bacterial products have been shown to travel in the blood to distant areas of the body, in this case penetrating the synovial layer surrounding the joint capsule.

The disease often develops after overcoming infections of the digestive (gastrointestinal) or urogenital (urogenital tract), but also after respiratory tract infections.

According to the infectious agent, they are subsequently divided into post-chlamydial reactive arthritis, enteroarthritis or arthritis after respiratory diseases.

The triggers can be microorganisms such as:

  • chlamydia
  • salmonella
  • shigella
  • campylobacter
  • yersinia
  • clostridium difficile
  • neisseria gonorrhoeae - causes gonorrhea, more often causes septic arthritis
  • ureaplasma urealyticum
  • boreliosis
  • mycoplazma pneumoniae
  • streptococcus pyogenes, more often in children

The presence of reactive arthritis after chlamydial infection is reported to be increased in adults, especially men. The impact of sexually transmitted diseases and the negative impact of frequent changes of sexual partners have also been proven.

This is one of the reasons why protection during an accidental sexual intercourse is so important.

It is also associated with some viruses (hepatitis, rubella, entero and adenoviruses) and HIV. A weakened human immune system is then more prone to a bacterial superinfection.

ReA also occurs in children.

In the context of childhood, it is reported that it may occur after upper respiratory tract infections, for example also after tonsillitis, i.e. inflammation of the tonsils.

Also read about the disease: rheumatic fever. It is a disease typical of the childhood after overcoming streptococcal infections of the upper respiratory tract and cervical tonsils caused by streptococcus.

Known facts about reactive arthritis:

  • higher risk of outbreak on HLA B27 antigen
  • most often between the ages of 20 and 40
  • in the case of the male sex, approximately 2 times higher risk than the complication of sexually transmitted disease
  • gastrointestinal ReA in men and women equal representation
  • in children more often after respiratory infections


The symptoms of the disease have two sides: in the joints or articular manifestations and extra-articular, i.e. symptoms other than those in the joints.

Table: Group of Major Symptoms

Articular problems Extra-articular problems
  • joint inflammation
  • joint swelling
  • joint pain
  • joint stiffness
  • impaired joint mobility
  • skin redness above the joint
  • increased skin temperature above the joint
  • tiredness
  • increase in body temperature to fever
  • weakness
  • general nausea
  • weight loss
  • lymph node enlargement
  • skin signs
  • peeling skin, reminiscent of psoriasis
  • keratoderma blennorrhagica - affects the soles of the feet and hands
  • including erythema nodosum
  • ulcers on the mucous membranes, in the mouth
Therefore, pain in the limbs and the surrounding area is also present
  • pain in the legs, lower back,
    radiating towards buttocks
  • the involvement of nearby structures is also present
    • tendons and tendon attachments, often pain in the Achilles tendon or leg
    • later on, the development of dactylitis - swelling of the fingers, reminiscent of sausages, sausage swelling of the finger
Urogenital problems
  • inflammation of the urinary tract and genitals
  • inflammation of the bladder or prostate
  • overactive bladder
  • burning and cutting when urinating
  • sometimes inflammation of the foreskin of the penis and glans
  • the most serious complication is glomerulonephritis with the risk of renal failure
The joints of the lower limbs are most often affected:
  • knee
  • ankle
  • hip joints
  • sacroiliac joints - connection of the pelvis and spine
    • sacroiliitis affects up to 95% of cases
  • spinal cord
  • it is usually a monoarticular form when only one joint is affected, but a maximum of 4 medium and large joints
  • polyarticular form when affected by more joints, less common
  • the upper limbs are affected less often
Digestive tract disorders
  • intestinal inflammation
  • stomach ache
  • diarrhea
  • resembling ulcerative colitis
Ocular manifestations
  • conjunctivitis - pink eye
  • redness of the eye
  • increased tearing
  • itchy eye, pain
  • feeling of sand in the eye
  • light sensitivity
  • visual impairment
  • as the most common complication of reactive arthritis
  • anterior uveitis - inflammation of the iris

Rarely, the disease can be complicated by severe heart disease, e.g. myocarditis (inflammation of the heart muscle) or endocarditis (inflammation of the inner membrane of the heart) with heart valve damage and heart failure.

In this case, there are cardiac problems such as:

A risky complication of cardiac arrhythmia and heart valve damage is the development of intra-cardiac thrombosis, when blood clots form in the heart cavities.

Consequently, there is a risk of embolization, which can clog a blood vessel elsewhere in the body and cause a heart attack or a stroke.


The diagnosis is based on the medical history, i.e. past occurrences of joint damage. The affected individual complains of a problem with one or more, medium or large joints. This is accompanied by the aforementioned general health problems.

This is followed by a physical examination and examination of the affected joint, its functionality, the skin above the joint and an evaluation of the presence of swelling.

The important thing to remember is that the joint symptoms do not occur until after another infection.

In the anamnesis it is necessary to find out from the previous period:

  • diarrhea
  • stomachache
  • urinary retention
  • sexual activity, especially in connection with a new or accidental sexual partner
  • possibly an infection in a partner

Laboratory blood tests such as CRP, sedimentation, baseline blood count, but also serology, antibody testing, HLA and others are added.

The collection and examination of joint effusion, which eliminates septic arthritis, is important.

A swab from the urethra or cervix in women is added to the screening to prove chlamydia.

X-ray, CT, MRI can be added as imaging methods.

Diagnostic criteria such as:

  • major criteria:
    • arthritis
      • asymmetrical
      • monoarthritis or oligoarthritis
      • mainly affects the lower limbs
    • previous infection
      • enteritis - inflammation of the small intestine
      • urethritis - inflammation of the urethra
  • minor criteria
    • positive swab from the urethra or cervix
    • positive cultivation from stool
    • synovial infection present
  • exclusion criteria - if other causes of acute arthritis are present

The presence of both major criteria and possibly one minor criterion, or the presence of one major and one or more minor criteria = ReA.


The course of the disease may be typical when the symptoms of joint involvement develop approximately 2 to 4 weeks after the onset of the primary infection. And so at this time there are no signs of the initial disease.

The onset time can range from 4 to 35 days.

It usually occurs after a infection of the genitourinary system, but also after a gastrointestinal infection.

Reactive arthritis is less common in children. In this case, there is a possibility that it will appear after an upper respiratory tract infection and tonsillitis.

This is one of the reasons why a thorough treatment for tonsillitis is very important.

The course may be mild when the difficulties subside after a certain time. However, in some cases it becomes complicated and severe.

About 10% of cases are also reported to develop cardiovascular problems, especially if reactive arthritis has a prolonged course of the disease.

ReA takes place mostly in a short period of time and
without serious health complications.
Sometimes it goes into a lengthy chronic form,
especially when not treated.

Reactive arthritis can have an acute course that has a rapid onset. Alternatively, there is a recurrent, but also chronic, progressive form.

It is reported that about 15-30% = chronic arthritis, 
15 - 50% recurrent form.

In the disease, there is a joint injury, which is accompanied by general fatigue, the output of body temperature. Alternatively, non-joint difficulties are also associated.

Typically, there is a triad of symptoms:

  1. arthritis - joint inflammation
  2. conjunctivitis - pink eye
  3. urethritis - inflammation of the urethra

The disease was described in 1916 by the physician Hans Reiter, after whom the disease was named, i.e. it was formerly known as Reiter's syndrome.

Nowadays, this name is not in use for several reasons.
Hans Conrad Julius Reiter was a German Nazi physician and war criminal.
He was not the first physician to make associations between the arthritis and other symptoms.
Terms such as arethritis urethritica, polyarthritis enterica or venereal arthritis were also used.

As already mentioned, the course of the disease can be complicated by several health problems. It is individual.

The prognosis is largely good when the disease does not affect quality of life. It is not debilitating. However, sometimes the disease recurs and takes on a progressive character, which worsens over time.

How it is treated: Reactive Arthritis

Treatment of reactive arthritis: medications, biological therapy and lifestyle changes

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Interesting resources

    • American College of Rheumatology. "Reactive Arthritis". Retrieved January 24, 2017.
    • Mayo Staff (March 5, 2011). "Reactive Arthritis (Reiter's Syndrome)". Mayo Clinic. Retrieved May 16, 2011.
    • H. Hunter Handsfield (2001). Color atlas and synopsis of sexually transmitted diseases, Volume 236. McGraw-Hill Professional. p. 148. ISBN 978-0-07-026033-7.
    • Primer on the Rheumatic Diseases, By John H. Klippel, page 218
    • Rheumatology in Practice, By J. A. Pereira da Silva, Anthony D. Woolf page 5.9
    • Ruddy, Shaun (2001). Kelley's Textbook of Rheumatology, 6th Ed. W. B. Saunders. pp. 1055–1064. ISBN 978-0-7216-9033-9.
    • Siala, Mariam; et al. (2008). "Analysis of bacterial DNA in synovial tissue of Tunisian patients with reactive and undifferentiated arthritis by broad-range PCR, cloning and sequencing". Arthritis Research & Therapy. BioMed Central. 10 (2): R40. doi:10.1186/ar2398. PMC 2453759. PMID 18412942.
    • Infectious Diseases Immunization Committee (1995). "Poststreptococcal arthritis". The Canadian Journal of Infectious Diseases6 (3): 133–135. doi:10.1155/1995/470341. PMC 3327910. PMID 22514384.
    • Retrieved 2019-09-18.
    • Sampaio-Barros PD, Bortoluzzo AB, Conde RA, Costallat LT, Samara AM, Bértolo MB (June 2010). "Undifferentiated spondyloarthritis: a longterm followup". The Journal of Rheumatology37 (6): 1195–1199. doi:10.3899/jrheum.090625. PMID 20436080. S2CID 45438826.
    • - The Case of Reactive Arthritis Secondary to Echinococcus Infestation