UMEM Educational Pearls

Category: Pediatrics

Title: Should blood cultures be drawn in a child with fever and lower extremity pain?

Keywords: fever, limp, bacteremia, osteomyelitis, septic joint (PubMed Search)

Posted: 7/21/2023 by Jennifer Guyther, MD (Updated: 5/21/2024)
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This was a cross sectional review of 698 patients ages 1 year to 18 years who presented to a tertiary care center with fever of at least 38 degrees centigrade and non traumatic acute lower extremity pain. This hospital was located in the North East of the United States. Lower extremity pain was defined as an antalgic gait by report or on exam, inability or refusal to bear weight or reported bone or joint pain in the verbal patient within the past 14 days.
Blood cultures were available for review in 510 patients.  Blood cultures were positive in 70 of them (13.7%).  Pathogens included MSSA, MRSA, Strep pyogenes and Salmonella.  Significant predictors of bacteremia included an elevated CRP and localizing exam findings.  
8 blood culture contaminants were identified.  6/8 of these patients had other testing and treatment consistent with osteomyelitis.  
The final diagnosis of the patients with bacteremia included osteomyelitis, septic arthritis, pyomyositis and toxic shock syndrome.
 
 
Bottom line: The prevalence of bacteremia, even in Lyme endemic areas, in healthy children presenting to the ED with fever AND lower extremity pain is high enough to strongly consider obtaining a blood culture with other lab work during the initial evaluation. 

References

El Helou R, Landschaft A, Harper MB, Kimia AA. Bacteremia in Children With Fever and Acute Lower Extremity Pain [published online ahead of print, 2023 Apr 4]. Pediatrics. 2023;e2022059504. doi:10.1542/peds.2022-059504