Septic Arthritis: Manifestations of Painful Infectious Joint Inflammation

Septic arthritis is an infectious inflammation of the joint. It is also referred to as infectious arthritis or also purulent arthritis. It occurs as a complication of inflammation elsewhere in the human body.

It is most commonly caused by bacteria.

Microorganisms enter the joint in two ways. Either from the environment, during an injury or inflammation of nearby structures. A good example is the route of transmission during joint puncture or injection of drugs or medicines.

The second mechanism is blood transmission. This can happen, for example, in upper respiratory tract infections and in untreated tonsillitis, when blood-borne bacteria settle in a joint.

It affects adults, but also children.

It most commonly affects one joint, the larger one, such as the knee or hip. However, in the case of a more severe course, it can affect several joints at the same time.

The risk of delay or neglect of treatment is complete and irreversible destruction of the joint. And in the most serious cases, it can even lead to health and life-threatening injuries.

Want to know more about infectious arthritis?
What causes it?
How does it manifest?
How is it treated?
Read on.

What is infectious arthritis?

Septic arthritis is an infectious inflammation of the joint. In its case, the provoking microorganism is directly proven in the joint. 

As a result of the infection, an inflammatory purulent effusion forms in the affected joint, which has a typical cloudy to cream-like colour. Therefore, this type of joint inflammation is also referred to as purulent arthritis.

Purulent = festering.

It is most often caused by a bacterial agent, however, viral or fungal inflammation can also occur.

It mostly affects adults and the elderly who have an associated other underlying disease, such as diabetes, pre-existing joint disease, but also people who have weakened immunity.

Plus, it occurs in children too. It is reported that in the childhood period, it most often affects children under 3 years of age.

Young children do not know how to describe their difficulties well, therefore, it is necessary to discloseproblems. Examples are outward manifestations of inflammation, such as swelling or redness of the joint, and the child's activity being stifled, on the grounds that movement aggravates the pain.

In adults, age above 80 years is listed as a risk age. However, with the development of medicine, inflammation after joint puncture, intra-articular injection or after surgical procedures on joints has become more common.

Thus, in this arthritis, the exact cause of the onset is unknown,
unlike rheumatic joint disease.

Infectious arthritis is dangerous mainly in terms of relatively rapid destruction of the joint. Therefore, its early detection and timely but also effective treatment are important.

The division of septic arthritis into non-gonococcal and gonococcal forms is practical and important. The non-gonococcal one is caused by different pathogens.

Gonococcal arthritis is caused by the bacterium Neisseria gonorrhoeae. The latter is behind the sexually transmitted disease - gonorrhea. 

They have some differences, but early detection and early treatment is common to both.

Table: nongonococcal and gonococcal septic arthritis compared

The largest proportion of septic arthritis is acute disease. Rarely, the chronic form occurs as a complication of tuberculosis or mycotic disease.

The cause of infectious arthritis is the transmission of infection from another area of the body directly into the joint. Two main mechanisms of transmission are reported.

The first one is...

The transmission of pathogens occurs by direct route from another nearby inflammation.

Injury, untreated superficial injury to the skin or penetrating injury through the skin to deeper layers is a risk. A similar pathway is inflammation of the bone near the joint - osteomyelitis.

It happens at any age.

Alternatively, the infection may be introduced into the joint during a joint puncture or when the medicine is injected into the joint. It happens that the infection develops after surgery on the joint, during artificial replacements and the like.

The second example of transfer is...

Bacteria and other microorganisms can also travel in the human body through the blood.

Haematogenous route = transmission of pathogens through the bloodstream.

This blood transmission is also in children as a result of upper respiratory tract inflammation and tonsillitis, which is an inflammation of the tonsils, also known as tonsillitis. Alternatively, it may be caused by an infection of the intestine or urinary tract.

Another example is inflammation of a tooth or the gums, when purulent vesicles are present, but also purulent deposits anywhere on the skin. In children, often also on the fingers of their hands, which they have injured and infected when playing outside, in the soil and so on.

This can also be due to a bite.

That is why even small injuries need to be treated and diseases need to be treated thoroughly.

As already mentioned, so specific inflammation is an infection of the joint in gonorrhoea, or chronic inflammation in tuberculosis.

Septic arthritis is caused by bacteria, viruses, fungi or parasites.

Pathogens that can trigger septic arthritis:

• Staphylococcus aureus (a.k.a. "golden staph" and "oro staphira") - over 50% of infections
• Streptococcus haemolyticus and Pseudomonas
• Staphylococcus epidermidis
• Streptococcus pyogenes, approximately 15-20% of cases
• Enterococcus faecium
• Enterococcus faecalis
• Haemophilus influenzae
• E. coli - Esherichia coli
• Klebsiella pneumoniae
• Salmonella species - causes salmonellosis
• Mycobacterium tuberculosis - tuberculosis
• Neiseria gonorhoeae - gonorrhoea
• Borrelia - Lyme boreliosis
• Proteus mirabilis
• Pseudomonas aeruginosa
• Bacteroides fragilis
• Candida albicans

Interesting facts:
Approximately 60% of infections are caused by golden staphylococcus aureus.
About 22% streptococcus.
For the sexually active, watch out for gonorrhea.
In children, enterobacteria, which are found all around us, in the soil, water, vegetation, are part of the intestinal microflora of every person.
In children, Kingella kingae - in upper respiratory tract infections. 

Of course, not every person who gets injured or has an inflamed throat or a joint puncture will develop septic arthritis.

Risk factors also play an important role.

Risk factors in the development of infectious arthritis:

• weakened immunity
• immunosuppressive therapy - when taking immunosuppressive drugs
• rheumatic joint diseases - rheumatoid arthritis, systemic lupus, juvenile arthritis in children and others
• chronické ochorenia ako
  • diabetes - diabetes mellitus
  • cirrhosis of the liver
  • kidney disease
  • oncological disease
  • haemophilia
  • HIV
• joint surgery and joint replacement (joint replacements), arthroscopy and others
• puncture of the synovial fluid of the joint
• application of the medicine to the joint
• injecting medicines and drugs - drug addiction
• alcoholism
• advanced age, especially over 60
• long-term treatment with corticosteroids
• skin infections near the joint
• inflammation of the upper respiratory tract, lungs, kidneys
• purulent wounds - especially untreated ones
• dialysis
• transplant
• low socio-economic status

According to reports, there is an approximate incidence of 2-10 cases per 100 000 inhabitants.

The symptom in septic arthritis will be a problem with the joint. Most commonly the disease affects the knee, hip, and the ankle. 

A rough division classifies arthritis thusly:

• monoarthritis - only 1 joint is affected
• oligoarthritis - up to 4 joints are affected
• polyarthritis - the inflammation affects 5 or more joints

What we do know:
The most common form is non-gonococcal monoarthritis. 
More than 50% of people have an inflamed knee.

Others besides the knees are the hips, ankles, elbows, shoulders, wrists, and the small joints of the hands and feet.

Remember:

Mostly it is an acute infection.

Polyarthritis occurs in a smaller proportion. It is present, for example, in young children under 3 years of age or in newborns.

In adults and sexually active people, it can be gonococcal polyarthritis. In this case, several joints are affected (polyarthritis) and it can be migratory. Thus, the involvement of individual joints alternates.

In chronic septic arthritis, one should look for yeast or tuberculosis.

And how does infectious arthritis manifest itself?

The most common symptoms of septic arthritis:

• joint swelling - the joint is full of inflammatory effusion, up to 90% of cases
• redness of the skin over the joint
• noticeably increased skin temperature in the inflamed area
• impaired joint function - limited mobility
• joint pain
• every movement and the smallest one - passive pain - will worsen the pain
• joint stiffness
• punctate, i.e. the fluid sucked out when the joint fissure is impaled, is cloudy, purulent, like cream
• overall symptoms
  • general weakness
  • fatigue
  • shivering - chills, when the body temperature rises
  • increase in body temperature to fever
  • accelerated heart rate and pulse
  • sweating
  • shortness of breath, pallor
  • loss of appetite
  • weight loss
  • young children show signs of
    • limping
    • refusal of movement activity
    • the child stays passive
    • does not want to move and play
    • PAY ATTENTION = an important sign that something is wrong with the child
    • an example is with hip inflammation that the baby cries when changing the diaper

Early detection and early treatment are important.
There is a risk of permanent and irreversible damage to the joint.

Diagnosis is done on the basis of medical history. A person complains of the present difficulties. The doctor examines the joint, obtains a clinical picture. Visible changes will support the restriction of movement and worsening of pain when moving.

Laboratory examination of blood, namely CRP, sedimentation, as well as basic blood count, in which there will be elevated values of leukocytes - white blood cells, hemoculture, will be supplemented.

An imaging examination will be added, namely:

• X-ray
• ultrasound
• CT
• MRI
• scintigraphy

This is followed by puncture of the joint - synovial fluid.

The punctate, or fluid injected from the joint, will be cloudy, purulent, resembling cream. The sample is sent for microbiological examination and antibiotic sensitivity.

Differential diagnosis and determining the exact cause of the difficulty is important. Specific inflammation will have a different treatment.

Others examples include:

• gout
• non-infectious arthritis, rheumatic diseases
• reactive arthritis
• osteoarthrosis
• fracture
• boreliosis
• and others

The course is acute in the overwhelming percentage of cases.

Sudden deterioration of joint mobility, which causes an accumulation of inflammatory purulent effusion. Of course, it is associated with externally visible swelling, redness of the skin over the joint with a higher skin temperature. 

Redness of the skin over the joint may not always be present.

The joint is stiff. The pain is pronounced and aggravated by the slightest movement.

There is associated general discomfort, as in other febrile illness, that is, fatigue, general weakness. The body temperature rises, even above 38 °C, accompanied by chills.

It is necessary to recognize the disease in young children, as they cannot tell what hurts them. Of course, external symptoms and general manifestations will be accentuated by general restlessness, crying, especially when moving. The child will be passive, will not play.

As already mentioned, it is mostly monoarthritis of one large joint.

Sometimes, however, there may be inflammation of several joints or medium-sized joints and small joints of the hand and foot.

The chronic course is less common. It usually accompanies diseases such as Lyme disease, tuberculosis (slow onset) or infection caused by the yeast Candida albicans.

In some people, the disease may also have an atypical course. This is mainly in the immunocompromised group, but also in drug addicts. The problem is that then the joint infection can be overlooked. 

In any case, immediate treatment is necessary, as septic inflammation of the joint causes its destruction quite quickly - even within a few days.

Neglect and delay in treatment can cause the infection to spread to the surrounding soft tissues. A state of general sepsis is also a risk.