Pediatric Fever of Unknown Origin

Droplet digital PCR aids in the diagnosis of children with fever of unknown origin --A typical case report

Many clinical conditions can cause fever of unknown origin (FUO) in children, but the etiological diagnosis remains challenging despite the variety of inspection methods available at present. This study aims to investigate the effectiveness of droplet digital polymerase chain reaction (ddPCR) in identifying pathogens in children with FUO as a novel application. A 7-month-old boy failed to obtain etiology evidence for his disease through various tests. After collecting peripheral blood for ddPCR analysis, Staphylococcus aureus and Escherichia coli were detected, and Sanger sequencing confirmed the pathogens. During the disease, the child developed septic arthritis and osteomyelitis in the femur. Despite the patient's fever being removed, his limb activity improving, and inflammatory biomarkers decreasing, avascular necrosis of the femoral head remained after targeted antibiotic treatment and surgery. If the patient had undergone ddPCR analysis at an early stage, it may be possible to avoid sequelae. ddPCR helps identify pathogens in the diagnosis of children with FUO and could be a promising complementary tool.

Antibiotic Use and Respiratory Viral PCR Testing Among Pediatric Patients With Nosocomial Fever

Objective Pediatric patients admitted to the hospital often develop fevers during their inpatient stay, and many children are empirically started on antibiotics. The utility of respiratory viral panel (RVP) polymerase chain reaction (PCR) testing in the evaluation of nosocomial fevers in admitted patients is unclear. We sought to evaluate whether RVP testing is associated with the use of antibiotics among inpatient pediatric patients. Patients and methods We conducted a retrospective chart review of children admitted from November 2015 to June 2018. We included all patients who developed fever 48 hours or more after admission to the hospital and who were not already receiving treatment for a presumed infection (on antibiotics). Results Among 671 patients, there were 833 inpatient febrile episodes. The mean age of children was 6.3 years old, and 57.1% were boys. Out of 99 RVP samples analyzed, 22 were positive (22.2%). Antibiotics were started in 27.8% while 33.5% of patients were already on antibiotics. On multivariate logistic regression, having an RVP sent was significantly associated with increased initiation of antibiotics (aOR 95% CI 1.18-14.18, p=0.03). Furthermore, those with a positive RVP had a shorter course of antibiotics compared to those with a negative RVP (mean 6.8 vs 11.3 days, p=0.019). Conclusions Children with positive RVP had decreased antibiotic exposure compared to those with negative RVP results. RVP testing may be used to promote antibiotic stewardship among hospitalized children.

Improving protocols for whole-body magnetic resonance imaging: oncological and inflammatory applications

Whole-body MRI is increasingly used in the evaluation of a range of oncological and non-oncological diseases in infants, children and adolescents. Technical innovation in MRI scanners, coils and sequences have enabled whole-body MRI to be performed more rapidly, offering large field-of-view imaging suitable for multifocal and multisystem disease processes in a clinically useful timeframe. Together with a lack of ionizing radiation, this makes whole-body MRI especially attractive in the pediatric population. Indications include lesion detection in cancer predisposition syndrome surveillance and in the workup of children with known malignancies, and diagnosis and monitoring of a host of infectious and non-infectious inflammatory conditions. Choosing which patients are most likely to benefit from this technology is crucial, but so is adjusting protocols to the patient and disease to optimize lesion detection. The focus of this review is on protocols and the elements impacting image acquisition in pediatric whole-body MRI. We consider the practical aspects, from scanner and coil selection to patient positioning, single-center generic and indication-specific protocols with technical parameters, motion reduction strategies and post-processing. When optimized, collectively these lead to better standardization of whole-body MRI, and when married to systematic analysis and interpretation, they can improve diagnostic accuracy.

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.

Hypothalamic-pituitary dysfunction in alternating hemiplegia of childhood

BACKGROUND

Many central nervous system disorders result in hypothalamic-pituitary (HP) axis dysfunction. Alternating Hemiplegia of Childhood (AHC) is usually caused by mutations in the ATP1A3 subunit of the Na⁺/K⁺ ATPase, predominantly affecting GABAergic interneurons. GABAergic interneurons and the ATP1A3 subunit are both important for function of the hypothalamus. However, whether HP dysfunction occurs in AHC and, if so, how such dysfunction manifests remains to be investigated.

METHODS

We conducted a retrospective review of a cohort of 50 consecutive AHC patients for occurrence of HP related manifestations and analyzed the findings of the 6 patients, from that cohort, with such manifestations.

RESULTS

Six out of 50 AHC patients manifested HP dysfunction. Three of these patients were mutation positive and 3 were mutation negative. Of the 6 patients with HP dysfunction, 3 had central precocious puberty. A fourth had short stature due to growth hormone deficiency. Two other patients had recurrent episodes of fever of unknown origin (FUO) diagnosed, after workups, as being secondary to central fever. All patients were evaluated and co-managed by pediatric neurology and endocrinology or rheumatology.

CONCLUSION

AHC was associated with HP dysfunction in about 12% of patients. Awareness of such dysfunction is important for anticipatory guidance and management particularly in the case of FUO which often presents a diagnostic dilemma. Our findings are also consistent with current understandings of the underlying pathophysiology of AHC and of the HP axis.

PET/Computed Tomography in the Evaluation of Fever of Unknown Origin and Infectious/Inflammatory Disease in Pediatric Patients

Fever in children is common. If it persists and its cause cannot be identified in a reasonable time, along with laboratory and conventional imaging investigations, it is defined as fever of unknown origin (FUO). 18F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) is well established in the evaluation of malignancy, which is a possible cause of FUO. FDG often locates inflammatory and infectious lesions considered nonspecific or false-positive for oncology; however, these findings are beneficial in FUO evaluation because infectious and inflammatory diseases are important FUO causes. FDG-PET/CT is being increasingly used for investigation of FUO as well as infectious/inflammatory disease.

Anti-N-Methyl-D-aspartate receptor encephalitis masquerading as fever of unknown origin

Fever of unknown origin (FUO) is a diagnostic challenge. Anti-N-methyl-D-aspartate receptor encephalitis should be considered in children with FUO and new-onset neurological symptoms without significant encephalopathy.

Low threshold for intracranial imaging in fever of unknown origin associated with cyanotic heart disease in the pediatric population

Intracranial abscess in the pediatric population is an overall rare occurrence-4 in a million. The most common predisposing factor is underlying cyanotic congenital heart disease (CCHD), which is associated with ~ 30% of all cases. We present an unusual case of cerebral abscess in a 17-month-old female with partially treated Tetralogy of Fallot and fever of unknown origin without associated neurologic symptoms. We propose a low threshold for intracranial imaging as part of the fever of unknown origin work-up in children with underlying cyanotic congenital heart disease.

Diagnosis of Kikuchi-Fujimoto disease in an 11-year-old girl with fever and sickle cell disease

Kikuchi-Fujimoto disease (KFD) is a rare lymphohistiocytic disorder which can cause prolonged fever and other systemic B symptoms including diffuse lymphadenopathy. Given its clinical presentation, there is often initial concern for lymphoma and diagnosis requires lymph node biopsy. It most frequently affects young women of Asian descent; it is less commonly encountered in paediatric patients. KFD is typically a benign, self-limited process, however, there is an association with development of systemic lupus erythematosus. Given its rarity, it remains unclear if KFD is associated with other chronic conditions. Here we present the third case of KFD occurring in a paediatric patient with sickle cell disease.

Fever of unknown origin: a retrospective review of pediatric patients from an urban, tertiary care center in Washington, DC

BACKGROUND

Fever of unknown origin (FUO) continues to challenge clinicians to determine an etiology and the need for treatment. This study explored the most common etiologies, characteristics, and average cost of hospitalization for FUO in a pediatric population at an urban, tertiary care hospital in Washington, DC.

METHODS

Records from patients admitted to Children's National Health System between September 2008 and April 2014 with an admission ICD-9 code for fever (780.6) were reviewed. The charts of patients 2-18 years of age with no underlying diagnosis and a temperature greater than 38.3 ºC for 7 days or more at time of hospitalization were included. Final diagnoses, features of admission, and total hospital charges were abstracted.

RESULTS

110 patients qualified for this study. The majority of patients (n = 42, 38.2%) were discharged without a diagnosis. This was followed closely by infection, accounting for 37.2% (n = 41) of patients. Rheumatologic disease was next (n = 16, 14.5%), followed by miscellaneous (n = 6, 5.4%) and oncologic diagnoses (n = 5, 4.5%). The average cost of hospitalization was 40,295 US dollars.

CONCLUSIONS

This study aligns with some of the most recent publications which report undiagnosed cases as the most common outcome in patients hospitalized with FUO. Understanding that, often no diagnosis is found may reassure patients, families, and clinicians. The cost associated with hospitalization for FUO may cause clinicians to reconsider inpatient admission for diagnostic work-up of fever, particularly given the evidence demonstrating that many patients are discharged without a diagnosis.

Prolonged Fever, Diarrhea, Abdominal Pain, and Joint Pain in a 9-Year- Old Boy

A 9-year-old African American boy was admitted to hospital with a 12-day history of fevers, diarrhea, abdominal pain and a 1-day history of joint pain. His abdominal pain and diarrhea resolved within the first few days of admission, but he continued with high-grade fevers and intermittent joint pain. The joints affected included the right first interphalangeal joint, right wrist, right elbow, and left knee joint. His initial laboratory tests revealed normal complete blood count, comprehensive metabolic panel, and C-reactive protein. Consequently, he developed fatigue, lower back pain, and bicytopenias. After 19 days of fevers, a multispecialty collaborative evaluation arrived at a final diagnosis and treatment plan. In this article, we discuss the child's hospital course and our clinical thought process. Written consent was obtained from the family.

Etiology and Resource Use of Fever of Unknown Origin in Hospitalized Children

BACKGROUND

Fever of unknown origin (FUO) is a well-known pediatric presentation. The primary studies determining the causes of prolonged fever in children were performed 4 decades ago, before major advances in laboratory and diagnostic testing. Given that the distribution of diagnosed causes of adult FUO has changed in recent decades, we hypothesized that the etiology of FUO in children has concordantly changed and also may be impacted by a definition that includes a shorter required duration of fever.

METHODS

A single-center, retrospective review of patients 6 months to 18 years of age admitted to the North Carolina Children's Hospital from January 1, 2002, to December 21, 2012, with an International Classification of Diseases, Ninth Revision diagnosis of fever, a documented fever duration >7 days before admission, and a previous physician evaluation of each patient's illness.

RESULTS

A total of 1164 patients were identified, and of these, 102 met our inclusion criteria for FUO. Etiologic categories included "infectious" (42 out of 102 patients), "autoimmune" (28 out of 102 patients), "oncologic" (18 out of 102 patients), and "other" or "unknown" (14 out of 102 patients). Several clinical factors were statistically and significantly different between etiologic categories, including fever length, laboratory values, imaging performed, length of stay, and hospital costs.

CONCLUSIONS

Unlike adult studies, the categorical distribution of diagnoses for pediatric FUO has marginally shifted compared to previously reported pediatric studies. Patients hospitalized with FUO undergo prolonged hospital stays and have high hospital costs. Additional study is needed to improve the recognition, treatment, and expense of diagnosis of prolonged fever in children.

Comparison of initial and final diagnoses in children with acute febrile illness: A retrospective, descriptive study: Initial and final diagnoses in children with acute fever

BACKGROUND

This study aimed to elucidate the etiologies and diagnostic errors of early-phase pediatric fever without an obvious cause.

METHODS

This single-center, retrospective, descriptive study included 1334 febrile children hospitalized at Beppu Medical Center in Japan between 2014 and 2018. Eligibility criteria were age ≤12 years, axillary temperature ≥38.0°C, and fever duration ≤7 days at admission. Initial diagnoses on the day of admission and final diagnoses at defervescence were divided into initial fever with identified source (FIS) and initial fever without source (FWS) and final FIS and final FWS, respectively. The etiology of initial FWS and diagnostic discordance between initial FIS and final FIS were investigated.

RESULTS

Of the 1334 participants, 94 (7.0%) were diagnosed with initial FWS. Among patients with initial FWS, final diagnoses were confirmed in 40 (43%), including Kawasaki disease in 17, urinary tract infection in 5, bacteremia in 4, exanthem subitum in 3, and the others in 11. Among the 1275 patients diagnosed with final FIS, diagnostic discordances between initial and final diagnoses were observed in 131 patients (10%). The multiple logistic regression analysis identified increased serum C-reactive protein value at admission (odds ratio [OR]: 1.09; 95% confidence interval [CI]: 1.06-1.13), exanthem subitum (OR: 409; 95% CI: 119-1399), and Kawasaki disease (OR: 14.3; 95% CI: 8.7-23.3) as independent risk factors for diagnostic discordance.

CONCLUSION

Exanthem subitum and Kawasaki disease may be undiagnosed or misdiagnosed in febrile children with fever duration ≤7 days.

Etiological distribution and clinical features of fever of unknown origin with pulmonary lesions in South China

INTRODUCTION

Fever of unknown origin (FUO) with pulmonary lesions is a common syndrome in respiratory diseases, which can be caused by infection, cancer, connective tissue disease and other rare diseases of South China. In patients with FUO associated with pulmonary lesions, pathogeny should be identified and followed by an appropriate treatment strategy.

OBJECTIVE

This study aimed to investigate the etiological distribution and clinical features of FUO with pulmonary lesions and to analyze the efficiency of different diagnostic methods for certain disease categories.

METHODS

Patients hospitalized at the Guangzhou Institute of Respiratory Health from July 2012 to December 2016 who had fever ≥38.3°C that lasted ≥21 days, in whom the chest X-ray or computed tomography (CT) revealed definite pulmonary infiltration, and for whom, despite being examined for a week, no definitive diagnosis could be made, were considered for this study.

RESULTS

A total of 104 patients were identified as having FUO with lung lesions, and 89.4% (93/104) patients were definitively diagnosed. Infectious disease was the most common cause (46.2%, 48/104). Histopathology was instrumental in the diagnosis of the causes of FUO with pulmonary manifestations, 47.3% (44/93) patients were diagnosed through histopathology, 35.4% (17/48) with infectious disease and 55.2% (16/29) with connective tissue diseases as the etiology were definitely diagnosed using histopathology.

CONCLUSION

Most FUO with pulmonary lesions are identified during infections and autoimmune diseases. The most important diagnostic measure for FUO with pulmonary lesions is histopathology. Additionally, lung biopsy must be encouraged in multi-level hospitals in the future.

The impact of global budgeting in Taiwan on inpatients with unexplained fever

Unexplained fever is one of the most common and difficult diagnostic problems faced daily by clinicians. This study evaluated the differences in health service utilization, health care expenditures, and quality of care provided to patients with unexplained fever before and after global budget (GB) implementation in Taiwan.The National Health Insurance Research Database was used for analyzing the health care expenditures and quality of care before and after implementation of the GB system. Patients diagnosed as having unexplained fever during 2000-2001 were recruited; their 2000-2001 and 2004-2005 data were considered baseline and postintervention data, respectively.Data of 259 patients with unexplained fever were analyzed. The mean lengths of stay (LOSs) before and after GB system implementation were 4.22 ± 0.35 days and 5.29 ± 0.70 days, respectively. The mean costs of different health care expenditures before and after implementation of the GB system were as follows: the mean diagnostic, drug, therapy, and total costs increased respectively from New Taiwan Dollar (NT$) 1440.05 ± NT$97.43, NT$3249.90 ± NT$1108.27, NT$421.03 ± NT$100.03, and NT$13,866.77 ± NT$2,114.95 before GB system implementation to NT$2224.34 ± NT$238.36, NT$4272.31 ± NT$1466.90, NT$2217.03 ± NT$672.20, and NT$22,856.41 ± NT$4,196.28 after implementation. The mean rates of revisiting the emergency department within 3 days and readmission within 14 days increased respectively from 10.5% ± 2.7% and 8.3% ± 2.4% before implementation to 6.3% ± 2.2% and 4.0% ± 1.7% after implementation.GB significantly increased LOS and incremental total costs for patients with unexplained fever; but improved the quality of care.

A Toddler With Prolonged Fever and Intermittent Cough

Fever of unknown origin is an important diagnostic challenge in pediatrics that requires a thoughtful approach. The differential diagnosis is broad and includes infectious, autoimmune, oncologic, neurologic, genetic, and iatrogenic causes. Infection remains the most common etiology, and uncommon presentations of infections are still more likely than classic presentations of rare conditions. We report a case of a retropharyngeal abscess in a toddler whose presentation is marked by a prolonged fever (>3 weeks). This case highlights the importance of close follow-up with serially repeated history and physical examinations to guide the evaluation of a patient with fever of unknown origin.

Approach to Neonates and Young Infants with Fever without a Source Who Are at Risk for Severe Bacterial Infection

INTRODUCTION

Among neonates and infants <3 months of age with fever without a source (FWS), 5% to 15% of cases are patients with fever caused by a serious bacterial infection (SBI). To favour the differentiation between low- and high-risk infants, several algorithms based on analytical and clinical parameters have been developed. The aim of this review is to describe the management of young infants with FWS and to discuss the impact of recent knowledge regarding FWS management on clinical practice.

MATERIALS AND METHODS

PubMed was used to search for all of the studies published over the last 35 years using the keywords: "fever without source" or "fever of unknown origin" or "meningitis" or "sepsis" or "urinary tract infection" and "neonate" or "newborn" or "infant <90 days of life" or "infant <3 months".

RESULTS AND DISCUSSION

The selection of neonates and young infants who are <3 months old with FWS who are at risk for SBI remains a problem without a definitive solution. The old Rochester criteria remain effective for identifying young infants between 29 and 60 days old who do not have severe bacterial infections (SBIs). However, the addition of laboratory tests such as C-reactive protein (CRP) and procalcitonin (PCT) can significantly improve the identification of children with SBI. The approach in evaluating neonates is significantly more complicated, as their risk of SBIs, including bacteremia and meningitis, remains relevant and none of the suggested approaches can reduce the risk of dramatic mistakes. In both groups, the best antibiotic must be carefully selected considering the clinical findings, the laboratory data, the changing epidemiology, and increasing antibiotic resistance of the most common infectious bacteria.

Pulmonary Alveolar Proteinosis in Association with Secondary Hemophagocytic Lymphohistiocytosis

Pulmonary alveolar proteinosis (PAP) is a rare diffuse lung disease in the pediatric population. There are currently few cases documenting hemophagocytic lymphohistiocytosis as a cause for secondary PAP. We describe an ex-preterm child with secondary hemophagocytic lymphohistiocytosis, complicated by PAP and hypoxemic respiratory failure.

Etiology and clinical characteristics of fever of unknown origin in children: a 15-year experience in a single center

Purpose

Fever is one of the most common symptoms in children. In previous studies, infectious disease was the most common cause of pediatric fever of unknown origin (FUO). The aim of this study is to investigate the etiology, clinical characteristics and prognosis of pediatric FUO in 21 century with more diagnostics available and to analyze the factors for certain disease categories.

Methods

Among the children under 18 years old who were hospitalized at Samsung Medical Center from January 2000 to December 2014, the patients who met the criteria including fever of ≥38.0℃ for longer than ≥14 days and failure to reach a diagnosis after one week of investigations were included.

Results

Total 100 patients were identified. Confirmed diagnosis was achieved in 57 patients (57%). Among them, infectious diseases (n=19, 19%) were most common, followed by connective tissue diseases (n=15, 15%), necrotizing lymphadenitis (n=8, 8%), and malignancies (n=7, 7%). Children with fever duration over 28 days had a trend for higher frequency of connective tissue diseases (28.3%) except undiagnosed etiology. The symptoms such as arthritis, lymph node enlargement and only fever without other symptoms were significantly related with connective tissue diseases, necrotizing lymphadenitis and undiagnosed respectively (P<0.001). Ninety-two patients have become afebrile at discharge and 1 patient died (1%).

Conclusion

Almost half of our patients were left without diagnosis. Although it has been known that infectious disease was most common cause of pediatric FUO in the past, undiagnosed portion of FUO have now increased due to development of diagnostic techniques for infectious diseases.

A Physician’s Nightmare: Fever of Unknown Origin

Fever of unknown origin (FUO) remains to be a challenge despite advancement in diagnostic technologies and procedures. FUO is considered when fever presents intermittently without an explanation. It has been linked to various etiologies, which makes it difficult to diagnose. We present the case of 18-month-old female with recurrent fever, splenomegaly, abdominal pain, and constipation. The workup for her symptoms revealed wandering spleen. Wandering spleen is a result from excessive laxity or absence of splenic ligaments. The patient underwent splenectomy and was advised to continue on Senna, Miralax, and high fiber diet. Her mother reported that the fever is no longer present and there is marked improvement in her constipation and abdominal pain after splenectomy.