Q: If bacterial/Septic arthritis is the presenting sign of infective endocarditis, what should be ruled out first?


 Answer: History of IV drug abuse

If septic arthritis is the presenting sign of infective endocarditis (IE), it is most likely due to IV drug abuse (IVDA), proved otherwise. In other words, if a patient known with IVDA, presents with bacterial arthrtis, it is mandatory to rule out IE. Most likely bugs in this scenario are staphylococcus aureus, enterococci, or streptococci. Again, any patient, who grew these bugs should be ruled out for IE.



Reference: 

 Sapico FL, Liquete JA, Sarma RJ. Bone and joint infections in patients with infective endocarditis: review of a 4-year experience. Clin Infect Dis 1996; 22:783.