When viewing this topic in a different language, you may notice some differences in the way the content is structured, but it still reflects the latest evidence-based guidance.

Last reviewed: 16 Mar 2025
Last updated: 15 Oct 2024

Summary

Definition

History and exam

Key diagnostic factors

  • hot, swollen, tender, restricted joint

Other diagnostic factors

  • low socioeconomic status
  • history of intravenous drug abuse
  • history of diabetes
  • history of cutaneous ulcers
  • prosthetic joint
  • history of rheumatoid arthritis or osteoarthritis
  • short history of symptoms
  • fever
  • history of alcohol use disorder
  • history of previous corticosteroid injection

Risk factors

  • underlying joint disease
  • joint prostheses
  • immunosuppression
  • contiguous spread (presence of cutaneous ulcers or skin infection)
  • previous intra-articular corticosteroid injection
  • recent joint surgery

Diagnostic tests

1st tests to order

  • synovial fluid Gram stain and culture
  • synovial fluid white cell count
  • blood culture
  • white cell count
  • erythrocyte sedimentation rate
  • CRP
  • plain radiograph
  • ultrasound

Treatment algorithm

Contributors

Authors

Gerald Coakley, PhD, FRCP
Gerald Coakley

Consultant Rheumatologist

Queen Elizabeth Hospital

London

UK

Disclosures

GC is an author of a reference cited in this topic.

Catherine J. Mathews, MSc, FRCP
Catherine J. Mathews

Consultant Rheumatologist

Queen Elizabeth Hospital

London

UK

Disclosures

CJM is an author of a reference cited in this topic.

Peer reviewers

Andrew Keat, MBBS

Consultant Physician and Rheumatologist

Northwick Park Hospital

Harrow

UK

Disclosures

AK declares that he has no competing interests.

Cheryl Main, MD, FRCPC

Medical Microbiologist

Infectious Disease Consultant

Hamilton Regional Laboratory Medicine Program

Hamilton Health Sciences

Hamilton

Canada

Disclosures

CM declares that she has no competing interests.

John Ross, MD

Brigham and Women’s Hospital

Hospitalist Section

Boston

MA

Disclosures

JR declares that he has no competing interests.

Use of this content is subject to our disclaimer