Acute Infectious Arthritis

Acute infections arthritis is an infection of the joints that develops over several hours to days. The infection is usually bacterial in nature – often caused by Staphylococcus aureus – and resides in tissues located in the joints.

Causes

Some of the risk factors for acute infectious arthritis have been identified, and are as listed below:

·         Age – the condition is highly prevalent in patients aged over 60;

·         Joint surgery;

·         Chronic infection and/or illness;

·         Pre-existing immunodeficiency;

·         Skin infections; and

·         Prosthetic implants in the joints.

Disease pathway

In most cases, acute infectious arthritis in a joint is due to bacteria in the bloodstream from an infection elsewhere in the body. It can also be caused by direct infection to the joint, caused by an open wound or surgery allowing bacteria into the site.

When bacteria are introduced to the joint, inflammation is triggered by the body’s innate immune response, giving rise to symptoms of the condition.

Symptoms and diagnosis

In some cases, days may elapse between the onset of acute infectious arthritis and the manifestation of its symptoms. These include:

·         Joint pain;

·         Warmth and/or redness; and

·         Restricted movement of the affected limb.

The main form of diagnosis for acute infections arthritis involves the analysis of fluid extracted from within the joint (synovial fluid). Synovial fluid with a foul odour suggests the presence of infection. An above-average white blood cell count would confirm this, as well as detection and identification of the bacteria.

Treatment

Initially, antibiotics are administered to patients, targeting the most common pathogens. Once clinical analysis has identified the specific pathogen, the antibiotics given are adjusted accordingly. 

Pus in the infected joints may be drained using a needle, while joint-splinting and exercises can help to reduce pain and recondition the joints.