Septic arthritis

Septic arthritis causes joint pain and swelling. Patients with gonococcal arthritis usually present with either purulent arthritis or pustular skin lesions with tenosynovitis and arthralgias. In the United States, up to 70% of infectious arthritis in adults <40 years is caused by N. gonorrhoeae.

CASES/YEAR
21,000 (US); 420,000 (Global)
CATEGORY
Localized Infections
AGENT TYPE
Mixed
OTHER NAMES
Infectious arthritis;
ACUITY
Acute-Severe
INCUBATION
Estimated: days to weeks;
INITIAL SYMPTOMS
Joint pain and swelling;
PRECAUTIONS
COMMENTS
FINDINGS:
Patients with gonococcal arthritis usually present with either purulent arthritis or pustular skin lesions with tenosynovitis and arthralgias. Other findings in septic arthritis are fever and leukocytosis. [ABX Guide] Up to 50% of patients with septic arthritis have positive blood cultures. The skin lesions in gonococcal arthritis may be pustular, maculopapular, or vesicular. [Cecil, p. 1763, 1765]

EPIDEMIOLOGY:
In the United States, up to 70% of infectious arthritis in adults <40 years is caused by N. gonorrhoeae. NAA (nucleic acid amplification) testing of synovial fluid is extremely sensitive. [Harrison ID, p. 265-6] Most common route is hematogenous seeding. Disseminated gonococcal infection is the most common etiology in young adults (2-3 times higher risk for females). S. aureus is most common in adults after N. gonorrhoeae. Risk increased for patients with rheumatoid arthritis, diabetes, glucocorticoid therapy, hemodialysis, malignancy, and IV drug use. Other causes are Lyme disease, tuberculosis, coccidioidomycosis, histoplasmosis, rubella, mumps, hepatitis B, and parvovirus infection. [Harrisons, p. 436-7] Known associations: Rheumatoid arthritis--S. aureus and Streptococcal species; IDU--S. aureus and P. aeruginosa; Dialysis--S. aureus; Unpasteurized milk and cheese--Brucella spp.; Sickle cell disease--Salmonella spp.; Diabetes--Group B Streptococcus; [ABX Guide] Patients with immune deficiencies are at risk for chronic joint infections. Causes include M. tuberculosis, M. marinum, M. kansasii, Candida sp, Coccidioides immitis, Histoplasmosis capsulatum, Cryptococcus neoformans, Blastomyces dermatitis, Sporothrix schenckii, Aspergillus fumigatus, Actinomyces israelii, and Brucella sp. [Merck Manual, p. 297]

VIRAL, FUNGAL, MYCOBACTERIAL, AND LYME ARTHRITIS:
Viral arthritis is usually limited to the period in which the systemic illness is active. Important causes are parvovirus 19, rubella, hepatitis B, HIV-1, HTLV-1, and chikungunya. Causes of fungal arthritis in healthy people include Blastomyces dermatitidis, Coccidioides spp., and Sporothrix schenckii. Candida spp., Cryptococcus, and Aspergillus cause arthritis in immunocompromised hosts. Patients with pulmonary tuberculosis may develop arthritis--usually hematogenous. Nontuberculous mycobacterial arthritis is usually secondary to penetrating wounds contaminated by soil or water. [PPID, p. 1410-15] About 60% of patients with untreated Lyme disease develop arthritis. In most cases, the arthritis is intermittent and resolves within a few years. NAA testing for Borrelia DNA is positive in about 85% of cases. [Harrison ID, p. 266]
DIAGNOSTIC
Synovial fluid examination: Gram stain &/or cultures; cell count (>50,000/mm3 neutrophilic leukocytosis), low glucose, & no crystals; Consider cultures (blood, cervix, throat, rectum) & NAAT for gonorrhea; Lyme serology if consistent history; [ABX Guide]
SCOPE
Global
SIGNS & SYMPTOMS
  • >arthralgia
  • >fever
  • H leukocytosis
  • S papules or plaques
  • S pustule
  • S skin blister or vesicles
  • *arthritis
  • *osteomyelitis
  • *sepsis
ANTIMICROBIC

Yes

VACCINE

No

ENTRY
Inhalation, Ingestion, Needle (Includes Drug Abuse), Scalpel or Transfusion, Skin or Mucous Membranes (Includes Conjunctiva), Animal Bite, Swimming, Sexual Contact
VECTOR
Biting Flies, Mosquitoes, Ticks
SOURCE
Person-to-Person, Human Fecal-Oral, Fecally Contaminated Soil, Animal Excreta, Animal Tissue, Soil or Dust (Ingesting or Inhaling), Waterborne (Ingesting, Inhaling, or Swimming)
RESERVOIR
Birds and Poultry, Cattle, Goats and Sheep, Cats, Deer, Elk and Antelope, Dogs, Fish and Shellfish, Horses, Monkeys, Rabbits, Rodents, Swine, Human, Wild Animals
RISK FACTORS
  • AIDS patients
  • Cancer patients
  • Injection drug users
TREATMENT
Empiric therapy is determined by initial synovial fluid Gram stain and risk factors; [ABX Guide]
DRUG LINK
REFERENCES FOR CASES/YEAR
1. (US) 4-10 per 100,000; [Gorbach, p. 356] Calculate: 7 X 3000 = 21000 in US;
2. (Global) 20 X US cases/yr = 420,000;