18th January 2024

Background

The acute hot joint is a common clinical presentation with a wide differential diagnosis, of which septic arthritis confers the highest morbidity and mortality. The British Society for Rheumatology (BSR) guidelines on management of the hot swollen joint state that:

“Patients with a short history of a hot, swollen and tender joint (or joints) with restriction of movement should be regarded as having septic arthritis until proven otherwise”.

Septic arthritis is defined as joint space infection which can occur in either a native or prosthetic joint. The most commonly implicated organism is Staphylococcus aureus. Other causes of bacterial septic arthritis include Streptococcus pneumonia, Salmonella species (associated with sickle cell disease), Pseudomonas aeruginosa (associated with IV drug use and puncture wounds) and Neisseria gonorrhoea (in those with concomitant gonococcal genitourinary infection).

Risk factors for development of septic arthritis include:

• Prosthetic joints
• Prior joint damage, such as from RA/gout
• Diabetes mellitus
• Immunodeficiency
• Intravenous drug use
• Recent steroid injections or joint surgery
• Bacterial infections at another site (haematogenous spread)
• Previous joint infection
• Older age