eMedicine Specialties > Rheumatology > Infectious Arthritis

Nongonococcal Infectious Arthritis: Differential Diagnoses & Workup

Author: Edward Dwyer, MD, Department of Medicine, Assistant Professor, Columbia University College of Physicians and Surgeons
Contributor Information and Disclosures

Updated: Oct 7, 2009

Differential Diagnoses

Calcium Pyrophosphate Deposition Disease
Gonococcal Arthritis
Gout
Rheumatic Fever
Rheumatoid Arthritis
Viral Arthritis

Workup

Laboratory Studies

  • Synovial fluid tests
    • The synovial fluid cell count is generally higher than 50,000/µL, with a predominance of neutrophils greater than 90% in persons with acute bacterial arthritis.
    • Results of a Gram stain of synovial fluid are positive in approximately 75% of patients with staphylococcal infections; however, results are positive in only 50% of patients with gram-negative infections.
    • A microscopic examination of synovial fluid for monosodium urate crystals and calcium pyrophosphate crystals is performed to exclude crystal-induced arthritis (eg, gout, pseudogout); however, recognizing the possibility of infectious arthritis and crystal-induced arthritis coexisting in a single joint is also important, although this is reportedly very uncommon.
    • A culture of synovial fluid should be performed for aerobic and anaerobic organisms. Inoculation of blood culture bottles is more sensitive than culture on solid medium, especially in patients pretreated with antibiotics.4
    • A biopsy of synovial tissue for culture and histologic examination is important if mycobacterial or fungal infections are suggested. A culture of synovial fluid is an insensitive diagnostic test in this setting.
  • Complete blood cell count
    • Leukocytosis is common in patients with acute bacterial arthritis.
    • Approximately 50% of persons with acute disease exhibit WBC counts greater than 10,000/µL.
  • Blood culture: Results are positive in approximately 33%-50% of patients with nongonococcal bacterial arthritis.6

Imaging Studies

  • Radiography
    • Plain radiography findings are generally nonspecific and may reveal only a joint effusion in the early stages of infection.
    • Cartilage destruction and joint space narrowing are late findings and may be difficult to interpret if the patient has a preexisting joint disease.
  • CT scanning: This study may help to diagnose sternoclavicular or sacroiliac joint infections.
  • MRI: MRI is most useful in assessing the presence of periarticular osteomyelitis as a causative mechanism.
  • Radionuclide images
    • Findings from radionuclide studies, such as bone scans, are positive for any inflammatory arthritis and are therefore very nonspecific.
    • These may be useful for diagnosing sternoclavicular or sacroiliac joint infection.

Procedures

  • Arthrocentesis with synovial biopsy
    • If indicated, this is the single most important diagnostic procedure for evaluating infectious arthritis.
    • It allows for culture and appropriate microscopic examination of the synovial fluid and tissue.

More on Nongonococcal Infectious Arthritis

Overview: Nongonococcal Infectious Arthritis
Differential Diagnoses & Workup: Nongonococcal Infectious Arthritis
Treatment & Medication: Nongonococcal Infectious Arthritis
Follow-up: Nongonococcal Infectious Arthritis
References
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References

  1. Chambers HF. Community-associated MRSA--resistance and virulence converge. N Engl J Med. Apr 7 2005;352(14):1485-7. [Medline].

  2. [Best Evidence] Mathews CJ, Kingsley G, Field M, Jones A, Weston VC, Phillips M, et al. Management of septic arthritis: a systematic review. Ann Rheum Dis. Apr 2007;66(4):440-5. [Medline].

  3. Shirtliff ME, Mader JT. Acute septic arthritis. Clin Microbiol Rev. Oct 2002;15(4):527-44. [Medline].

  4. von Essen R. Culture of joint specimens in bacterial arthritis. Impact of blood culture bottle utilization. Scand J Rheumatol. 1997;26(4):293-300. [Medline].

  5. Kaandorp CJ, Krijnen P, Moens HJ, Habbema JD, van Schaardenburg D. The outcome of bacterial arthritis: a prospective community-based study. Arthritis Rheum. May 1997;40(5):884-92. [Medline].

  6. Goldenberg DL, Reed JI. Bacterial arthritis. N Engl J Med. Mar 21 1985;312(12):764-71. [Medline].

  7. Smith JW, Chalupa P, Shabaz Hasan M. Infectious arthritis: clinical features, laboratory findings and treatment. Clin Microbiol Infect. Apr 2006;12(4):309-14. [Medline].

  8. Gupta MN, Sturrock RD, Field M. A prospective 2-year study of 75 patients with adult-onset septic arthritis. Rheumatology (Oxford). Jan 2001;40(1):24-30. [Medline].

  9. Harrington JT. Mycobacterial and fungal arthritis. Curr Opin Rheumatol. Jul 1998;10(4):335-8. [Medline].

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Further Reading

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Keywords

bacterial arthritis, fungal arthritis, candidal arthritis, mycobacterial arthritis, septic arthritis, infectious arthritis, non-gonococcal arthritis, nongonococcal infectious arthritis, non-gonococcal infectious arthritis, infected joint prosthesis, joint prosthesis infection, staphylococcal arthritis

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Contributor Information and Disclosures

Author

Edward Dwyer, MD, Department of Medicine, Assistant Professor, Columbia University College of Physicians and Surgeons
Edward Dwyer, MD is a member of the following medical societies: Alpha Omega Alpha and American College of Rheumatology
Disclosure: Nothing to disclose.

Medical Editor

Robert E Wolf, MD, PhD, Professor Emeritus, Department of Medicine, Louisiana State University Health Sciences Center at Shreveport; Chief, Rheumatology Section, Medical Service, Overton Brooks Veterans Administration Medical Center of Shreveport
Robert E Wolf, MD, PhD is a member of the following medical societies: American College of Rheumatology, Arthritis Foundation, and Society for Leukocyte Biology
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Elliot Goldberg, MD, Dean of the Western Pennsylvania Clinical Campus, Professor, Department of Medicine, Temple University School of Medicine
Elliot Goldberg, MD is a member of the following medical societies: Alpha Omega Alpha, American College of Physicians, and American College of Rheumatology
Disclosure: Nothing to disclose.

CME Editor

Alex J Mechaber, MD, FACP, Associate Dean for Undergraduate Medical Education, Associate Professor of Medicine, University of Miami Miller School of Medicine
Alex J Mechaber, MD, FACP is a member of the following medical societies: Alpha Omega Alpha, American College of Physicians-American Society of Internal Medicine, and Society of General Internal Medicine
Disclosure: Nothing to disclose.

Chief Editor

Herbert S Diamond, MD, Professor of Medicine, Temple University School of Medicine; Chairman Emeritus, Department of Internal Medicine, Western Pennsylvania Hospital
Herbert S Diamond, MD is a member of the following medical societies: Alpha Omega Alpha, American College of Physicians, American College of Rheumatology, American Medical Association, and Phi Beta Kappa
Disclosure: medifocus Honoraria Review panel membership; health dialogs Honoraria Consulting; West Penn Allegheny Health System None Board membership

 
 
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