Whole-body magnetic resonance imaging in the evaluation of children with fever without a focus.

BACKGROUND: Fever without a focus is defined as a temperature of 38° C or higher as the single presenting symptom. After extensive investigation, a large percentage (12-67%) of cases remain undiagnosed. OBJECTIVE: To assess the diagnostic value of whole-body magnetic resonance imaging (WB-MRI) in children with fever without a focus. MATERIALS AND METHODS: A retrospective study was performed to identify children who underwent WB-MRI for fever without a focus. Ninety-two children, 50 boys, with a mean age of 6.1 years were included. A multidisciplinary team of physicians completed in consensus a medical record review that included: 1) immune status, 2) underlying chronic conditions, 3) hospitalization status at onset of fever, and 4) results of tissue, body fluid cultures and biopsies. Original MRI reports were evaluated. WB-MRI studies were categorized into helpful WB-MRI and not helpful WB-MRI. RESULTS: A final diagnosis for the cause of the fever was available for 68/92 cases (73.9%), which were determined to be infectious in 33/68 (48.5%), oncological in 3/68 (4.4%), rheumatological etiologies in 23/68 (33.8%) and miscellaneous in 9/68 (13.2%) cases. WB-MRI was found to be helpful in 62/92 cases (67.4%) and not helpful in 30/92 cases (32.6%). WB-MRI was 10.2 times less likely to be helpful in immunosuppressed children and almost 5.7 times less likely to be helpful in cases of prolonged fever (>3 weeks) at the time of MRI (P≤0.01). CONCLUSION: WB-MRI provides helpful information in approximately 2/3 of children with fever without a focus. In most cases, it was helpful to exclude the need of further investigation.

Factors contributing to the non-identification of bacterial meningitis in febrile infants: A case series study.

Non-identification of serious bacterial infection (SBI) in febrile infants is a common occurrence in clinical practice, culminating in catastrophic presentations. Six infants who initially presented to the clinician with fever without a focus, and were lately diagnosed with bacterial meningitis were analyzed for clinician-related factors contributing to the non-identification of meningitis. In a febrile neonate and a febrile young infant, lack of comprehensive evaluation was contributing to the non-identification of SBI; in four infants above the age of 3 months, meningitis was missed in spite of clinicians practicing treatment guidelines. Inadequate symptom characterization in two febrile infants and inappropriate interpretation of hemogram in three febrile infants also contributed to the non-identification of meningitis. Except for one, all infants developed complications. We conclude that the characterization of clinical features of SBI-like meningitis, interpretation of lab data, and adherence to the treatment guidelines are crucial in the management of an infant presenting as fever without a focus.

Clinical characteristics and outcomes in febrile infants aged 29-90 days with urinary tract infections and cerebrospinal fluid pleocytosis.

Introduction: Fever without a focus is a common reason for medical evaluations, hospitalizations, and the antimicrobial treatment of infants younger than 90 days. The presence of cerebrospinal fluid (CSF) pleocytosis could be challenge for clinicians who treat febrile young infants with urinary tract infection (UTI). We evaluated the factors associated with sterile CSF pleocytosis and the clinical outcomes of the patients. Methods: A retrospective review of patients aged 29-90 days with febrile UTIs who underwent a non-traumatic lumbar puncture (LP) at Pusan National University Hospital from January 2010 to December 2020 was conducted. CSF pleocytosis was defined as white blood cell (WBC) counts ≥9/mm3. Results: A total of 156 patients with UTI were eligible for this study. Four (2.6%) had concomitant bacteremia. However, no patients had culture-proven bacterial meningitis. In correlation analysis, although weak strength, CSF WBC counts were positively correlated with C-reactive protein (CRP) level (Spearman r = 0.234; P = 0.003). Thirty-three patients had CSF pleocytosis [21.2%; 95% confidential interval (CI), 15.5-28.2]. The time from fever onset to the hospital visit, peripheral blood platelet counts, and CRP level at admission were statistically significant in patients with sterile CSF pleocytosis compared to those without CSF pleocytosis. In the multiple logistic regression, only CRP was independently associated with sterile CSF pleocytosis (cutoff, 3.425 mg/dl; adjusted odds ratio, 2.77; 95% CI, 1.19-6.88). The proportion of fever defervescence by hospital day 2 was 87.9% in patients with CSF pleocytosis and 89.4% in those without CSF pleocytosis (P = 0.759). There was no statistical difference in the fever defervescence curves between the two patient groups (P = 0.567). No patients had neurological manifestations or complications. Conclusions: Coexisting sterile CSF pleocytosis among febrile infants with UTIs suggest a systemic inflammatory response. However, the clinical outcomes between the two groups were similar. A selective LP should be considered in young infants with evidence of UTI, and inappropriate antibiotic therapy for sterile CSF pleocytosis should be avoided.