What factors predispose an individual to develop septic arthritis?
• Impaired host defense (50%)
• Neoplastic disease
• Elderly (>80 years old) or children (<5 years old)
• Chronic, severe illness (i.e., alcoholism, diabetes, cirrhosis, chronic renal disease, and human immunodeficiency virus [HIV])
• Cutaneous ulcers and skin infections
• Sickle cell disease (susceptible to encapsulated organisms due to functional hyposplenia)
• Hypogammaglobulinemia (susceptible to Mycoplasma infections)
• Immunosuppressive agents (i.e., glucocorticoids, chemotherapy, biologics)
• Direct penetration
Intravenous (IV) drug abuse; puncture wounds; invasive procedures (intraarticular corticosteroid injections)
• Joint damage
Prosthetic joints (over 50% occur in patients aged over 70 years)
Chronic arthritis (i.e., RA, hemarthrosis, osteoarthritis)
• Host phagocytic defects
Late complement–component deficiencies (susceptible to Neisseria ); impaired chemotaxis