Septic Arthritis Causes

1. Causes: General
   1. Staphylococcus aureus
      1. Most common cause of Septic Arthritis in all ages
2. Causes: Septic Arthritis Causes based on age
   1. Infant (age <3 months, contiguous spread from Osteomyelitis)
      1. Staphylococcus aureus (common)
      2. Neisseria gonorrhoeae (common)
      3. Enterobacteriaceae
      4. Group B Streptococcus
   2. Children (age 3 months to 14 years)
      1. No cause identified in one third of cases
      2. Staphylococcus aureus (27%)
      3. Streptococcus (14%)
         1. Streptococcus Pyogenes
         2. Streptococcus Pneumoniae
      4. HaemophilusInfluenzae (<3% of cases, much less common in U.S. since start of Hib Vaccine)
      5. Gram Negative Bacilli
         1. Kingella kingae (preschool children
   3. Adults with STD risk
      1. Neisseria gonorrhoeae (most common)
         1. See Gonococcal Arthritis
         2. Gonorrrhea is a still a leading cause in young adults with Septic Arthritis
         3. More common in women by a factor 3-4
         4. Typically Migratory Arthritis
      2. Staphylococcus aureus
      3. Streptococcus
      4. Gram Negative Bacilli
      5. Syphilis
   4. Adults with no STD risk
      1. Staphylococcus aureus (50%)
      2. Streptococcus species
      3. Gram Negative Bacilli
3. Causes: Iatrogenic or Trauma related Septic Arthritis
   1. Joint Aspiration or injection
      1. Staphylococcus aureus
   2. Joint Trauma or wound
      1. Gram Negative Bacilli
      2. Anaerobic Bacteria
      3. Staphylococcus aureus
      4. Polymicrobial infections
   3. Joint prosthesis
      1. Early infection
         1. Staphylococcus epidermidis
      2. Late Infection
         1. Gram Positive Cocci
         2. Anaerobic Bacteria
   4. Umbilical catheter (UAC or UVC) use in the newborn
      1. Risk of septic hip
4. Causes: Septic Arthritis related to Comorbid Medical Conditions
   1. Intravenous Drug Abuse
      1. Atypical Gram Negative Bacilli (e.g. Pseudomonas)
   2. Rheumatoid Arthritis
      1. Staphylococcus aureus
      2. Streptococcus
      3. Gram Negative Bacilli
   3. Systemic Lupus Erythematosus or Sickle Cell Anemia
      1. Salmonella
   4. Hemophilia
      1. Staphylococcus aureus
      2. Streptococcus
      3. Gram Negative Bacilli
   5. Hemoglobinopathy (e.g. Sickle Cell Anemia)
      1. Salmonella
   6. Immunodeficiency
      1. Staphylococcus aureus
      2. Mycobacterium species
      3. Fungus
      4. Gram-Negative Bacteria
5. Causes: Chronic Monoarticular Arthritis
   1. Brucella
   2. Nocardia
   3. Mycobacterium
   4. Fungus
6. Causes: Acute Polyarticular Septic Arthritis
   1. See Polyarticular Joint Pain Causes
   2. Neisseria gonorrhoeae (most common)
   3. Lyme Disease
   4. Acute Rheumatic Fever
   5. Viral Hepatitis
   6. Parvovirus B19
   7. Syphilis
7. Causes: Septic Arthritis related to Occupation or Travel
   1. Gardening or agricultural
      1. Sporothrix schenckii
      2. Brucella
   2. Marine related
      1. Mycobacterium marinum
   3. Immigrant
      1. Mycobacterium tuberculosis
8. References
   1. Gilbert (2012) Sanford Guide to Antimicrobials
   2. Stimmler (1996) Postgrad Med 99(4):127-39 [PubMed]