Brucella bloodstream infection mimicking systemic juvenile idiopathic arthritis: a pediatric case report.

BACKGROUND

Systemic juvenile idiopathic arthritis (sJIA) accompanied with Brucella bloodstream and bone marrow infection is an exceedingly rare occurrence in clinical practice. Owing to the striking similarity in their clinical presentations, there is a propensity for misdiagnosis or underdiagnosis.

CASE PRESENTATION: In this case, the pediatric patient underwent medical treatment across five different hospitals over a three-month period before receiving an accurate diagnosis and successful treatment. There are two primary factors contributing to this consequence. To begin with, Brucella exhibits slow growth, leading to initial blood cultures producing false negative results due to insufficient cultivation time. Additionally, sJIA and brucellosis present extremely similar clinical symptoms. In addition to arthritis, the child presented with a non-fixed erythematous rash that gradually resolved after fever subsided and was associated with increased IL-6 levels. Furthermore, both blood and bone marrow cultures displayed positive results after four days, and Brucella was identified through MALDI-TOF mass spectrometry. Combined with additional laboratory results and clinical symptoms, sJIA accompanied with Brucella bloodstream infection was ultimately diagnosed and effectively managed in our hospital.

CONCLUSION

It is crucial to emphasize that in cases of brucellosis infection, the identification of sJIA and brucellosis is of vital significance. Brucella can be isolated and cultured from blood and bone marrow within approximately two weeks, serving as the definitive indicator for diagnosing Brucella bloodstream infection. By reporting this case, we aim to share clinical experience, provide a more accurate and expedited diagnosis, as well as treatment for future patients encountering similar circumstances.