Fever of Unknown Origin in Childhood

Prolonged Fever in Children: An Inpatient Diagnostic Framework for Infections in Australia

There are many causes of fever in children, ranging from common and self-limiting to serious and life threatening. Careful assessment of children with prolonged fever without an obvious or identified source requires detailed history and examination with consideration of infections unique to the specific geographical region and individual exposure risks. Previous recommendations for diagnostic work-up have provided valuable insights, but none have been tailored to the Australian inpatient setting. Recognising this gap, a diagnostic approach for infections specifically designed for the Australian child admitted to hospital with prolonged fever (≥  38.0°C) exceeding 7 days is provided. LEVEL OF EVIDENCE: National Health and Medical Research Council Level V.

Indoor air quality and symptoms of acute respiratory infections and gastrointestinal issues in children and employees in day-care nurseries

BACKGROUND

Children attending day-care centers (DCCs) experience more infections than those cared for at home and DCC employees have high sickness absence rates. This study aimed to investigate the association between indoor air quality and absenteeism among children and staff in DCCs.

METHODS

CO2 levels, relative humidity (RH), and temperature were continuously measured in 22 DCCs over 3 winter months. Simultaneously, absenteeism due to sickness was recorded for 721 children and 213 employees. In 11 DCCs, staff received training to improve ventilation.

RESULTS

The median CO2 concentration, RH, and temperature were 818 ppm, 38.7%, and 20.8 °C, respectively. Acute respiratory infections (ARIs) accounted for 42% of child absenteeism and 53% of staff absenteeism, while gastrointestinal symptoms (GI) were responsible for 24.7% and 27.3% of absenteeism in children and staff, respectively. No significant association was found between ARI absenteeism and CO2 concentration, RH, or temperature. However, a significant association was observed between GI and room temperature (P < .05). No significant differences in CO2 concentration or absenteeism were observed between intervention and control groups.

CONCLUSIONS

No statistical evidence was found that ARI absenteeism was associated with the measured indoor air quality parameters. GI for staff and children was significantly associated with room temperature. Absenteeism was not associated significantly with targeted interventions.

Fever of unknown origin in pediatrics: role of nuclear medicine

Fever of unknown origin (FUO) is a debated issue in numerous scientific studies in adult patients with a not jet-defined workflow in a clinical and diagnostic setting. Few works are published about pediatric patients even if FUO represents a challenging, not infrequent scenario in hospital and outpatient recovery. The fever might be the onset symptom of a transient mild infection or the beginning of a more difficult-to-diagnose and serious pathological condition. In the adult workflow 18FDG PET-CT is nowadays playing a relevant role, considering the limited spread of conventional 99mTc-HMPAO-White Blood Cells scintigraphy. It represents a robust tool for diagnosing the eventual site of infection, but it is limited by procedural complexity and long duration, up to 24 hours. The WBC-scintigraphy is also not suitable for children, only for young adults or adolescents, considering the relevant blood sample entity and the procedural risk for sensitive subjects. The most assessed clinical and diagnostic know-how on Pediatric FUO are summarized and a synthetic flow-chard is presented to support the clinical management and to choose the best diagnostic pathway.

Fever of Unknown Origin

Fever of unknown origin in adolescents is a challenging disease state for which potential underlying etiology can include infectious, non-infectious inflammatory, and malignancy processes. Careful and thorough history (including exposure history), serial examination, and targeted laboratory and imaging testing is critical for these patients. In adolescents in which an etiology is discovered, infectious etiology remains the most prevalent, followed by non-infectious inflammatory diseases. In patients with non-diagnostic overall reassuring work up, the prognosis is typically self-limiting and favorable.

Update on Fever of Unknown Origin in Children: Focus on Etiologies and Clinical Approach

Fever of unknown origin (FUO) can be caused by four etiological categories of diseases. The most common cause of FUO in children is represented by infections, followed by inflammatory conditions and neoplastic causes; a decreasing quote remains still without diagnosis. Despite the fact that several diagnostic and therapeutic approaches have been proposed since the first definition of FUO, none of them has been fully validated in pediatric populations. A focused review of the patient's history and a thorough physical examination may offer helpful hints in suggesting a likely diagnosis. The diagnostic algorithm should proceed sequentially, and invasive testing should be performed only in select cases, possibly targeted by a diagnostic suspect. Pioneering serum biomarkers have been developed and validated; however, they are still far from becoming part of routine clinical practice. Novel noninvasive imaging techniques have shown promising diagnostic accuracy; however, their positioning in the diagnostic algorithm of pediatric FUO is still not clear. This narrative review aims to provide a synopsis of the existent literature on FUO in children, with its major causes and possible diagnostic workup, to help the clinician tackle the complex spectrum of pediatric FUO in everyday clinical practice.

Are children with prolonged fever at a higher risk for serious illness? A prospective observational study

OBJECTIVES

To describe the characteristics and clinical outcomes of children with fever ≥5 days presenting to emergency departments (EDs).

DESIGN

Prospective observational study.

SETTING

12 European EDs.

PATIENTS

Consecutive febrile children <18 years between January 2017 and April 2018.

INTERVENTIONS

Children with fever ≥5 days and their risks for serious bacterial infection (SBI) were compared with children with fever <5 days, including diagnostic accuracy of non-specific symptoms, warning signs and C-reactive protein (CRP; mg/L).

MAIN OUTCOME MEASURES

SBI and other non-infectious serious illness.

RESULTS

3778/35 705 (10.6%) of febrile children had fever ≥5 days. Incidence of SBI in children with fever ≥5 days was higher than in those with fever <5 days (8.4% vs 5.7%). Triage urgency, life-saving interventions and intensive care admissions were similar for fever ≥5 days and <5 days. Several warning signs had good rule in value for SBI with specificities >0.90, but were observed infrequently (range: 0.4%-17%). Absence of warning signs was not sufficiently reliable to rule out SBI (sensitivity 0.92 (95% CI 0.87-0.95), negative likelihood ratio (LR) 0.34 (0.22-0.54)). CRP <20 mg/L was useful for ruling out SBI (negative LR 0.16 (0.11-0.24)). There were 66 cases (1.7%) of non-infectious serious illnesses, including 21 cases of Kawasaki disease (0.6%), 28 inflammatory conditions (0.7%) and 4 malignancies.

CONCLUSION

Children with prolonged fever have a higher risk of SBI, warranting a careful clinical assessment and diagnostic workup. Warning signs of SBI occurred infrequently but, if present, increased the likelihood of SBI. Although rare, clinicians should consider important non-infectious causes of prolonged fever.

Chromosomal abnormalities related to fever of unknown origin in a Chinese pediatric cohort and literature review

BACKGROUND

Fever of unknown origin (FUO) has been difficult to diagnose in pediatric clinical practice. With the gradual change in the disease spectrum, genetic factors have received increasing attention. Limited studies have shown an association between FUO and chromosomal abnormalities. In this study, we investigated the clinical and genetic characteristics of patients with FUO presenting with chromosomal abnormalities in a Chinese pediatric cohort.

RESULTS

Chromosomal abnormalities were detected in 5.5% (8/145) of the patients with FUO. Six patients with inflammatory fever presented with pharyngitis/amygdalitis (4/6), oral aphthous ulcer (2/6), digestive symptoms (3/6), developmental delay (4/6) and elevated C-reactive protein levels (6/6) during fever. These patients were often considered to have systemic inflammatory diseases, such as Behcet's disease or systemic juvenile idiopathic arthritis. Trisomy 8, 7q11.23 dup, 3p26.3-p26.1 del/17q12 dup, 22q11.21 del, and 6q23.3-q24.1 del were identified in patients with inflammatory fever. The TNFAIP3 gene was included in the 6q23.3-q24.1 deletion fragment. Two patients with central fever were characterized by facial anomalies, developmental delay, seizures and no response to antipyretic drugs and were identified as carrying the de novo 18q22.3-q23 del. By performing a literature review, an additional 19 patients who had FUO and chromosomal abnormalities were identified. Trisomy 8, 6q23.2-q24.3 del and 18q22.3-q23 del were reported to present as fever, similar to the findings of our study.

CONCLUSIONS

We emphasized the important role of detecting chromosomal abnormalities in patients with FUO, especially in patients with systemic inflammatory manifestations or developmental delay. Identifying chromosomal abnormalities may change the diagnosis and management of patients with FUO.

Fever of unknown origin (FUO) in children: a single-centre experience from Beijing, China

OBJECTIVE

To date, there is no standard diagnostic practice to identify the underlying disease-causing mechanism for paediatric patients suffering from chronic fever without any specific diagnosis, which is one of the leading causes of death in paediatric patients. Therefore, we aimed this retrospective study to analyse medical records of paediatric patients with fever of unknown origin (FUO) to provide a preliminary basis for improving the diagnostic categories and facilitate the treatment outcomes.

DESIGN

A retrospective study.

SETTING

Beijing Children's Hospital.

PARTICIPANTS

Clinical data were collected from 1288 children between 1 month and 18 years of age diagnosed with FUO at Beijing Children's Hospital between January 2010 and December 2017.

INTERVENTIONS

According to the aetiological composition, age, duration of fever and laboratory examination results, the diagnostic strategies were analysed and formulated.

PRIMARY AND SECONDARY OUTCOME MEASURES

The statistical analyses were carried out using SPSS V.24.0 platform along with the χ² test and analysis of variance (p<0.05).

RESULTS

The duration of fever ranged from 2 weeks to 2 years, with an average of 6 weeks. There were 656 cases (50.9%) of infectious diseases, 63 cases (4.9%) of non-infectious inflammatory diseases (NIIDs), 86 cases (6.7%) of neoplastic diseases, 343 cases (26.6%) caused by miscellaneous diseases and 140 cases (10.9%) were undiagnosed. With increasing age, the proportion of FUO from infectious diseases gradually decreased from 73.53% to 44.21%. NIID was more common in children over 3 years old, and neoplastic diseases mainly occurred from 1 to 6 years of age. Among miscellaneous diseases, the age distribution was mainly in school-aged children over 6 years. Respiratory tract infection was the most common cause of FUO in children, followed by bloodstream infections. Bacterial infection was the most common cause in children with less than 1 year old, while the virus was the main pathogen in children over 1 year old.

CONCLUSIONS

The diagnosis of neoplastic diseases and miscellaneous diseases-related diseases still depends mainly on invasive examination. According to our clinical experience, the diagnostic process was formulated based on fever duration and the type of disease. This process can provide a guide for the diagnosis and treatment of paediatric FUO in the future.

[Fever for 2 months and disturbance of consciousness for 1 week in a preschool-aged girl]

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation syndrome (ROHHADS) is a rare multi-system disease, and delayed diagnosis and treatment may lead to catastrophic cardiopulmonary complications. As far as we know, no patient with ROHHADS has been reported in China, and this article reports a child with ROHHADS to improve the awareness of this disease among clinicians. A girl, aged 3 years, had the clinical manifestations of rapid weight gain, fever, disturbance of consciousness, and convulsion. The physical examination showed a body weight of 20 kg, somnolence, irregular breathing, and stiff neck. She had increased blood levels of prolactin and follicle-stimulating hormone and hyponatremia. The lumbar puncture showed an increased intracranial pressure. The brain MRI and magnetic resonance venography showed symmetrical lesions in the periventricular region and venous thrombosis in the right transverse sinus and the superior sagittal sinus. The sleep monitoring showed hypopnea. The girl was finally diagnosed with ROHHADS and intracranial venous thrombosis. She recovered after symptomatic treatment including decreasing intracranial pressure, anticoagulation, and respiratory support. The possibility of ROHHADS should be considered for patients with unexplained obesity, fever, and hypoventilation, with or without central nervous system symptoms. Early diagnosis and standardized follow-up can improve the prognosis of children with ROHHADS.

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.

[Fever of unknown origin]

Fieber unklarer Genese wird diagnostiziert, wenn das Fieber (meist definiert als Körpertemperatur ≥ 38,3 °C, gemessen rektal oder am Trommelfell) länger dauert als erwartet, also nach 5 bis 10 Tagen. Die Ursachensuche kann sich schwierig gestalten und bedarf der erhöhten Aufmerksamkeit des erfahrenen Allgemeinpädiaters in Zusammenarbeit mit pädiatrischen Infektiologen, Rheumatologen und Onkologen, der Pflege, Radiologen und anderen. In etwa der Hälfte der Fälle findet sich am Ende doch eine Infektion; weitere Ursachen sind primär entzündliche oder onkologische sowie nichtentzündliche Erkrankungen. Einzelne Ursachen mit der Gefahr des schweren Verlaufs müssen sofort behandelt werden. Ansonsten gibt es ein klares Primat der Diagnostik, die klug geplant und sowohl zielstrebig als auch breit durchgeführt wird. Anamnese, physikalischer Befund, Laborbestimmungen, apparative Diagnostik, bildgebende und histologische Untersuchungen können zur Diagnose beitragen. Die Eltern sind durch die Ungewissheit hindurchzuführen, und dem Kind sollte die Situation möglichst erleichtert werden. Es kommen auch Spontanheilungen vor. Die probatorische Gabe von Antibiotika führt selten zur Besserung. Nach weitgehendem Ausschluss von Infektion, Malignom und zunehmendem Leiden unter dem Fieber selbst, können bei hoher Entzündungsaktivität, unter dem Verdacht auf einen hyperergen Status und nach ausführlicher Aufklärung Glukokortikoide angesetzt werden. Das Management des Fiebers unklarer Genese ist eine der großen Herausforderungen der Pädiatrie.

Pyrexia in juvenile dogs: a review of 140 referred cases

Objectives

To describe the presentation, influence of previous treatment and diagnosis in juvenile dogs presenting with pyrexia to a UK referral centre.

Materials and Methods

Clinical records of dogs aged 1 to 18 months presenting with a problem list including pyrexia (≥⃒39∙2°C) that was reproducible during referral hospitalisation were retrospectively reviewed. Signalment, history ‐ including previous treatment, clinical examination findings and diagnosis were recorded. Diagnoses were categorised as non‐infectious inflammatory, infectious, congenital, neoplastic and miscellaneous. The influence of previous treatment on the ability to reach a final diagnosis was analysed.

Results

A total of 140 cases was identified. Diagnosis was reached in 115 cases. Non‐infectious inflammatory disease was identified in 91 cases (79%), infectious disease in 19 cases (17%), a congenital disorder in four dogs (3%) and neoplasia in one dog (1%). Breeds most commonly identified were Border collies (17/140; 12%), beagles (16/140; 11%), Labrador retrievers (11/140; 8%), springer spaniels (9/140; 6%) and cocker spaniels (8/140; 6%). Before presentation, most dogs had received antibiotics (83/140; 59%), non‐steroidal anti‐inflammatory drugs (84/140; 60%) or steroids (9/140; 6%), either alone or in combination. Neither antibiotics nor non‐steroidal anti‐inflammatory drugs influenced the ability to reach a diagnosis. Steroid‐responsive meningitis‐arteritis comprised 55 of 91 (60%) individuals of the non‐infectious inflammatory cohort. All four dogs diagnosed with congenital disorders were Border collies.

Clinical significance

Non‐infectious inflammatory disease, particularly steroid‐responsive meningitis‐arteritis, immune‐mediated polyarthritis and metaphyseal osteopathy, was commonly diagnosed in this population of pyrexic juvenile dogs.

Radionuclide Imaging of Infection and Inflammation in Children: a Review

With the exception of radiolabeled monoclonal antibodies, antibody fragments and radiolabeled peptides which have seen little application in the pediatric population, the nuclear medicine imaging procedures used in the evaluation of infection and inflammation are the same for both adults and children. These procedures include (1) either a two- or a three-phase bone scan using technetium-99m methylene diphosphonate; (2) Gallium 67-citrate; (3) in vitro radiolabeled white blood cell imaging (using ¹¹¹Indium-oxine or ^99mTechnetium hexamethyl-propylene-amine-oxime-labeled white blood cells); and (4) hybrid imaging with ¹⁸F-FDG. But children are not just small adults. Not only are the disease processes encountered in children different from those in adults, but there are developmental variants that can mimic, but should not be confused with, pathology. This article discusses some of the differences between adults and children with osteomyelitis, illustrates several of the common developmental variants that can mimic disease, and, finally, focuses on the increasing use of ¹⁸F-FDG PET/CT in the diagnosis and response monitoring of children with infectious and inflammatory processes. The value of and need for pediatric specific imaging protocols are reviewed.