Staphylococcus aureus is the most common cause of septic arthritis
In older children S aureus is the most common pathogen followed by group A streptococcus and N Gonorrhoeae.
Where MRSA is common empiric therapy in children should cover this organism with vancomycin or clindamycin depending on local susceptibility patterns. Kingella kingae is a common pathogen for osteoarticular infections especially those less than five years of age and would not be covered by either of these agents and may merit the use of a cephalosporin.
Other potential pathogens:
- Streptococcus pneumoniae (children less than two years old)
- Haemophilus influenzae type b (historically and in unvaccinated patients)
- Group B streptococcus, Candida albicans and gram negative organisms such as E coli (in children less than 3 months of age)
- Salmonella species (sickle cell disease)
Saavedra-Lozano J, Falup-Pecurariu O, Faust SN, Girschick H, Hartwig N, Kaplan S, Lorrot M, Mantadakis E, Peltola H, Rojo P, Zaoutis T, LeMair A. Bone and Joint Infections. Pediatr Infect Dis J. 2017 Aug;36(8):788-799. PMID: 28708801
Liu C, Bayer A, Cosgrove SE, Daum RS, Fridkin SK, Gorwitz RJ, Kaplan SL, Karchmer AW, Levine DP, Murray BE, J Rybak M, Talan DA, Chambers HF; Infectious Diseases Society of America. Clinical practice guidelines by the infectious diseases society of america for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children. Clin Infect Dis. 2011Feb 1;52(3):e18-55. PMID: 21208910