Common Cause Of Fever Of Unknown Origin Research Articles

Fever of unknown origin in pediatrics: causes and clinical characteristics in a single centre experience

BackgroundFever of unknown origin (FUO) is a common condition worldwide in children that remains a diagnostic challenge. The causes of FUO vary depending on the patient's age, residency, and the time of study. Therefore, this study aimed to identify the common aetiologies of FUO at Alexandria University Children’s Hospital under the current diagnostic abilities and newly emerging diseases.MethodsThe current prospective observational study included all children fulfilling the definition of FUO admitted at Alexandria University Children's Hospital from January 2020 to December 2021 using a steps approach for investigations.ResultsA total of 110 children with fever of unknown origin (FUO) were included in this study; the average duration of fever was 36.76 ± 31.73 days. In most of the enrolled cases 105/110 (95.4%) the definite etiology of FUO was identified. The common causes were collagen vascular diseases (30.9%), infectious diseases (28.2%), miscellaneous conditions (19.1%), and malignancy (17.3%). Among collagen vascular diseases, systemic lupus erythematosus (SLE) (47.1%) and systemic onset juvenile idiopathic arthritis (sJIA) (38.2%) were the most common. In the infectious category, Katayama fever (16.1%), brucellosis (12.9%), and urinary tract infection (UTI) (12.9%) were the most frequently observed. Post-Covid MIS-C (52.4%) was the most common in the miscellaneous category. Children in the infectious category had significantly higher neutrophil [5.76 (2.28–7.92) × 10^3/µl] and lymphocytic counts [ 4.2 (2.04–5.91) × 10^3/µl]; (P < 0.001 and < 0.010 respectively). Moreover, in the collagen category the median lymphocytic count was lower [1.95 (1.47–2.73) × 10^3/µl] with a significantly (P < 0.010) higher neutrophil/ lymphocyte ratio [2.30 (1.53–3.91)].ConclusionCollagen vascular diseases, infectious diseases, miscellaneous, and malignancy were the most common causes of FUO. Katayama fever, urinary tract infections (UTI), and brucellosis were the most common causes in the infectious category. Post-Covid MIS-C and hemophagocytic lymphohistiocytosis were the most common diagnoses in the miscellaneous category.

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.

Fever of Unknown Origin in Children: The Challenge of History Taking

A fever of unknown origin (FUO) in children is usually described as a fever of at least 8 days duration with no apparent diagnosis after initial investigations, including taking medical history and preliminary laboratory assessment. Infectious diseases are the most common cause of FUO, followed by rheumatologic and neoplastic conditions. In this report, we present a case of a 15-year-old Caucasian boy with a silent past medical history, who presented at our Pediatric ER department with a three-day history of fever, fatigue, and abdominal pain with diarrhoea. Initial laboratory testing and microbiological work-up were non-significant. At hospital admission, a broad infectious diagnostic work-up was pursued, including serologies and polymerase-chain-reaction (PCR) for CMV, EBV, HAV, Parvovirus, Toxoplasma gondii and Adenovirus, all negative. Given mild splenomegaly and linfadenopathy, systemic Juvenile Idiopathic Arthritis (s-JIA) was suspected, as well as Multi-inflammatory Syndrome in Children (MIS-C), but the patient did not meet their main diagnostic criteria. Malignancy was ruled out by a negative bone marrow fine-needle aspiration cytology and whole-body PET-CT scan. On hospital day 8, Brucella was identified on a new set of blood cultures and a combined antibiotic therapy was started with IV Gentamicin plus per os Doxycycline. The patient’s general conditions rapidly improved, and both fever and diarrhoea resolved. A reassessment of the patient’s medical history before discharge revealed exposure to unpasteurized soft cheese in the weeks prior to the onset of symptoms. This case underlines the importance of taking a complete medical history, as well as a full diagnostic work-up to unveil unusual infectious etiologies behind FUO. After the preliminary negative microbiological tests, a connective tissue disease was ruled out (i.e. lack of cutaneous or articular involvement), as well as malignancy, which led to a closer evaluation for infection and the diagnosis of Brucellosis.

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

ObjectiveTo 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...

Fever of Unknown Origin - Different Centuries, Different Patterns

Background: Imaging techniques used in the last decades, and reported changes in various disease prevalence, may have dramatically influenced causes of Fever of Unknown Origin (FUO) Objectives: Our study’s objectives were to identify changes in prevalence and etiologies of FUO, since our previous study two decades ago, to clarify the most beneficial diagnostic strategies, and to investigate the long-term outcomes of undiagnosed and diagnosed patients Methods: Medical files with “fever” as a cause for admission and at least one-week hospitalization were evaluated. Patients were screened based on Petersdorf’s classic criteria. An interview was performed three months to twelve years after hospitalization Results: 3691 patients fit our primary selection criteria in 2004-2016; 141 patients fit Petersdorf’s criteria for FUO. The most common cause of FUO was infectious disease (39%), mainly bacterial (29%), though decreased from our previous study (39% vs 55%). There were dramatic increases in the incidence of malignancy (19% vs 7.9%) and inflammatory (20% vs 2%) etiologies and less undiagnosed cases (22% vs 32.7%). Weakness and weight loss were the most common co-complaints (80% all coexisted). Elevated ESR (97%), elevated CRP (95%) and anemia (80%), were the most common pathologic laboratory examinations found. Abdominal CT, blood cultures and serology proved to be the most valuable diagnostic tests. Long-term follow up interviews revealed that a final diagnosis was often reached during the patients’ next admission (20% out of 70%). 2% of patients died during the feverish episode and 34% died three months to twelve years after the episode Conclusions: Infections (mainly bacterial) remain the most common cause for FUO in southern Israel in the 21th century; although there is a remarkable increase in the rate of vasculitis and malignancy. When PET is not available, a thorough clinical examination including appropriate laboratory and imagine examination, as well as precise history taking are essential. Blood cultures and abdominal CT are the most useful diagnostic tests. Most undiagnosed cases resolved within days of discharge or are diagnosed in a following admission

Etiology of fever of unknown origin in children.

Objectives: To determine the etiology of Fever of Unknown Origin (FUO) in children. Study Design: Prospective Observational study. Setting: Department of Pediatric Medicine, The Children's Hospital, Lahore. Period: August 2019 to January 2020. Material &amp; Methods: A total of 45 children aged between 01 to 180 months (15 years), having FUO were included. FUO was defined as a temperature of greater than 100.4ºF documented by a health care provider, persisting over a period of three weeks and for which no cause could be identified after at least 8 days of evaluation. All the study information was analyzed by using standard software SPSS 20. The quantitative variables like age and duration of fever before hospital admission were presented as mean and standard deviation. Qualitative variables like sex, antibiotic therapy use before definitive diagnosis and various diagnoses made were presented as frequencies and percentages. Results: The patient’s age range was from 01 to 180 months with mean of 80±45.12 months and male to female ratio was 2.2:1. Definitive diagnosis was made in 37(82.2%) patients. Infections were the predominant cause of FUO (44.4%) followed by malignancy (24.4%). Tuberculosis was the most common infection while Acute Lymphoblastic leukemia dominated the malignancy. Systemic lupus erythematosus was the most commonly diagnosed connective tissue disorder. There was a significant association between duration of fever and the ultimate diagnosis (p=0.01). Conclusion: Infectious diseases were the most common cause of FUO followed by malignancy, connective tissue disorders and miscellaneous causes.

Role of FDG-PET/CT in children with fever of unknown origin

PurposeTo determine the role of 18F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET)/computed tomography (CT) in children with fever of unknown origin (FUO).MethodsThis retrospective single-center study included 110 children (0–18 years) with FUO who underwent FDG-PET/CT between 2010 and 2019. The diagnostic value of FDG-PET/CT for identifying cause of fever was calculated, treatment modifications after FDG-PET/CT were assessed, and logistic regression analyses were performed to identify clinical and biochemical factors associated with FDG-PET/CT outcome.ResultsIn 53 out of 110 patients (48%), FDG-PET/CT identified a (true positive) cause of fever. Endocarditis (11%), systemic juvenile idiopathic arthritis (5%), and inflammatory bowel disorder (5%) were the most common causes of FUO. In 42 patients (38%), no cause of fever was found on FDG-PET/CT. In 58 out of 110 patients (53%), treatment modifications were made after FDG-PET/CT. FDG-PET/CT achieved a sensitivity of 85.5%, specificity of 79.2%, positive predictive value of 84.1%, and negative predictive value of 80.9%. On multivariate logistic regression, C-reactive protein was positively associated with finding a true positive focus of fever on FDG-PET/CT (OR = 1.01 (95% CI 1.00–1.02) per mg/L increase in CRP), while leukocyte count was negatively associated with finding a true positive focus of fever (OR = 0.91 (95% CI 0.85–0.97) per 109 leukocytes/L increase).ConclusionFDG-PET/CT is a valuable diagnostic tool in the evaluation of children with FUO, since it may detect a true underlying cause in almost half (48%) of all cases where none was found otherwise. It allows full-body evaluation in patients without disease-specific symptoms on one examination. CRP and leukocyte count were significantly associated with FDG-PET/CT results, which may contribute to a priori assessment on the outcome of FDG-PET/CT. Future research could be aimed at evaluating more patient-specific factors to prospectively estimate the added value of FDG-PET/CT in children with FUO.

Etiology of Fever of Unknown Origin in Shiraz: A Southern Iranian Experience

Background: Although infectious diseases are the most common cause of fever of unknown origin (FUO) in many countries, the spectrum of its etiology is changing over time. Objectives: The purpose of this study was to determine the clinical spectrum and the pattern of FUO in Shiraz. Methods: This study was undertaken from 2011 to 2015 in the main hospitals of Shiraz, southern Iran. The data of 60 patients fulfilling the modified criteria for FUO referring to the main hospitals in Shiraz were used for analysis. The data were extracted from the patients’ medical charts and probable etiologies responsible for FUO were assessed. The patients were followed up by further ambulatory and readmission assessment. Results: Of the identified etiologies, infections were the most common cause of FUO in 30% of the patients, followed by collagen vascular diseases with 15% and malignancies with 11.6%. However, 25 patients (41%) remained undiagnosed for their fever causes. Conclusions: The pattern of FUO in the region has changed in recent years and complicated cases are admitted to hospitals. With improving ambulatory tests and diagnostic modalities, most of the patients with FUO are being diagnosed in outpatient settings and it will cause some changes in the classic percentage of FUO etiologies among admitted patients in the future.

Nedeni bilinmeyen ateş: 30 çocuk hastanın değerlendirilmesi

Purpose: The aim of this retrospective study is to evaluate the etiology clinical and laboratory features of fever of unknown origin (FUO) diagnosed in 30 pediatric patients. Materials and methods: The clinical data including the etiology, diagnostic approaches and clinical characteristics were retrospectively analysed in 30 pediatric patients with FUO who presented to our clinic in one year period. Results: The median age of the patients was 63 (6-192) months. Among the patients, 12 were male (40%), while 18 were female (60%). The median duration of the fever was 22.5 (3-60) days during hospital admission. The most common physical findings were hepatomegaly and splenomegaly, which were observed in 53. 3 and 40 patients, respectively. The cause of the FUO was detected to be infection in 14 patients (46.6%), connective tissue-vascular diseases in 8 patients (26.7%), malignancies in 5 patients (16.7%), and miscellaneous diseases in 1 patient (3.3%). In two patients (6.6%) the etiology could not be identified. Leishmaniasis, tuberculosis and brucellosis were the most commonly identified infections, whereas juvenile rheumatoid arthritis and acute lymphoblastic leukemia were the most common non-infectious causes. Conclusion: The most common cause of FUO in our study was infection diseases. Connective-vascular tissue diseases and malignancies are also important causes of FUO. In our opinion, detailed patient history, carefully physical examination and close clinical follow-up may reduce the number of the invasive procedures and non-invasive tests.

Fever of unknown origin in rheumatology

The article considers the current state of the problem related to fever of unknown origin (FUO). It highlights the main stages of studying this issue with a detailed description of the classification diagnostic criteria, etiological types, and clinical signs of certain types of FUO, which have undergone changes over time. The authors present a differential diagnostic algorithm for managing patients with FUO and analyze the diagnostic value of the most significant laboratory and instrumental studies. PPP-syndrome is described as one of the possible etiological factors for FUO. The circle of the most common of FUO is denoted in patients at different ages. It is noted that rheumatic diseases are the most common cause of FUO in elderly patients.

Clinical analysis of 215 consecutive cases with fever of unknown origin: A cohort study.

Fever of unknown origin (FUO) is a frequently observed phenomenon in clinical practice. The present study was aimed to investigate potential causes of FUO, thereby improving clinical diagnosis of this disorder.In this retrospective study, clinical data were collected from 215 patients who were diagnosed with FUO between January 2009 and December 2010, and an 18 to 36 months follow-up visit was also performed for these patients.Among these FUO cases, the most common causes of the disease were infectious diseases (IDs) (42.3%), followed by connective tissue diseases (CTDs) (32.1%), miscellaneous (Mi) (10.7%) and neoplasm (N) (6.5%), while the causes for the other 18 cases (8.4%) were still unknown. The most common types of ID, CTD, and N were tuberculosis (16/91, 17.6%), adult onset Still disease (AOSD) (37/69, 53.6%) and non-Hodgkin lymphoma (6/14, 42.9%), respectively.IDs still represent the most common causes of FUO. Regularly intermittent fever with urinary infections and irregularly intermittent fever with infective endocarditis may be regarded as some signs in clinical diagnosis of FUO.

Fever Of Unknown Origin In Children: A Five-Year Review

Objective: The clinical presentation, outcome, and risk factors for mortality in children with Fever of Unknown Origin (FUO) were determined. Methods: Medical records of pediatric patients admitted for FUO from January 2009 to December 2013 were reviewed. Clinical manifestations, physical exam findings, diagnostic work-ups and final diagnosis were determined, as well as the relationship between final diagnosis and risk for mortality. Results: Fifty-seven patients with FUO were included. Weight loss, cough, colds, and rashes were common symptoms while pallor, lymphadenopathies, and hepatomegaly were common physical exam findings. All patients underwent Phase I evaluation for FUO, while 73.7% underwent further diagnostic tests. A specific etiology was established in 96.5% of cases: infectious, 43.9%, connective tissue disease, 38.6%, and hematologic/oncologic, 14%. Two cases remained to have no specific diagnosis. Majority of patients had a benign course and were discharged improved (84.2%). The mortality rate is 15.8% and was not associated with any disease category (p-value 0.204). Conclusion: FUO in children occurs across all age groups. Its clinical presentations are varied and non-specific and common signs and symptoms are pallor, lymphadenopathies, weight loss, cough, colds. and joints pains. Infection is the most common cause of FUO in children, followed by connective tissue diseases and hematologic and oncologic diseases. The mortality rate from FUO is 15.8%.

Lung Lesions During Fever of Unknown Origin.

Fever of unknown origin (FUO) remains one of the most difficult diagnostic challenges. The causes of FUO can be various diseases located in different organs. The aim of the study was to determine the prevalence and nature of pulmonary lesions during FUO. One hundred and sixty one patients with FUO participated in this prospective study. We performed a detailed comprehensive history, physical examination, and a wide spectrum of tests. The most common causes of FUO were infections (39%), autoimmune conditions (28%), and neoplasms (17%). Lung lesions were found in 30% of patients. In this group 35% were infections, 30% autoimmune diseases, and 4% cancer. Among patients with respiratory infections, there were cases of tuberculosis, atypical pneumonia, lung abscess, and bronchiectases. Autoimmune pulmonary lesions were observed during vasculitis and systemic lupus. The causes of FUO in the group of patients with lung lesions were also pulmonary embolism, sarcoidosis, and pulmonary fibrosis. Chest CT played an important role in the diagnosis of the causes of FUO with pulmonary manifestations. Pulmonary lesions are a common cause of FUO. Most FUO with pulmonary lesions are recognized during infections and autoimmune diseases. An important part of diagnosing FUO is a detailed evaluation of the respiratory system.

Aetiology of Fever of Unknown Origin: One-Year Experience in a Tertiary Care Hospital of Bangladesh

Background: Fever of unknown origin (FUO) is not an uncommon problem in general medical practice. Sometimes extensive investigations fail to reach an aetiological diagnosis; on the other hand, in few cases, fever resolves spontaneously. This study was aimed to evaluate the aetiology of FUO in a tertiary care setting.Methods: This cross-sectional study was done in the Department of Internal Medicine of BIRDEM General Hospital, Dhaka, Bangladesh from July 2012 to June 2013.Results: Among the 33 patients studied (1.23% of total admissions), 22 (66.7%) were male. Mean age of the study population was 40.2±7.9 years. Most patients (84.8%) were diabetic. Infection (20, 60.6%) was the commonest cause, followed by malignancy (9, 27.3%). Among the infective causes (20), extra-pulmonary tuberculosis (5, 25%) was the commonest, followed by liver abscess (4, 20%). Other less common causes were Kala-azar (1), malaria (2), histoplasmosis (2), melioidosis (1), cholecystitis (1), renal abscess (1), rickettsial fever (1), apical dental abscess (1) and infective endocarditis (1). Non-Hodgkin’s lymphoma (6), renal cell carcinoma (2) and hepatocellular carcinoma (1) constituted the malignant causes of FUO in this series. Systemic lupus erythematosus was the aetiology of FUO in 1 case. One case remained undiagnosed and 2 patients left hospital before a definite diagnosis could be made.Conclusion: Extra-pulmonary tuberculosis and non-Hodgkin’s lymphoma were the two most common causes of FUO in this study. Repeated history taking, clinical examinations and careful stepwise investigations can diagnose the aetiolgy in most cases of FUO.Birdem Med J 2016; 6(1): 7-11

Choroby nowotworowe i autoimmunologiczne u dzieci jako istotne przyczyny gorączki o nieustalonej etiologii

IntroductionFever is one of the most common reasons why parents and a child go to the pediatrician. Fever of unknown origin (FUO) is a very difficult diagnostic problem. ObjectiveThe study aims were retrospective analysis of causes of FUO and periodic fevers in children and trying to prepare a diagnostic algorithm. Material and methodsThe study involved 77 children, aged 1–19 years who were hospitalized in the Department of Pediatrics, Oncology and Hematology and the Department of Pediatrics, Cardiology and Rheumatology in the years 2005–2011. Since the work is retrospective, qualifications for the study took place on the basis of medical records such as a medical history. The study group included children who had a temperature over 38°C lasting more than 3 weeks or appearing on a regular basis every 3–4 weeks without an obvious cause. ResultsThe most common cause of FUO was neoplastic diseases (48%), especially acute lymphoblastic leukemia. Other diagnoses were made in 41.6%. Among them, in 15.6% patients autoimmune diseases and other immunological syndromes, in 7.8% periodic fever syndromes and in 18.2% infectious diseases were diagnosed. 10.4% patients were without final diagnosis. Very important in diagnostic process was analysis of concomitant signs and symptoms. ConclusionsInfectious, autoimmune and noeplastic diseases should be concerned in a differential diagnosis of FUO. Appropriate questions, physical examinations and basic laboratory tests often allow to make the correct diagnosis. The proposed diagnostic algorithm might be helpful to a successful diagnostic process.

Clinico-epidemiological profile of fever of unknown origin in an Egyptian setting: A hospital-based study (2009-2010).

Fever of unknown origin (FUO) is one of the most challenging diagnostic dilemmas in the field of infectious diseases and tropical medicine. Clinicians should use the frequency distribution of disorders causing FUO to guide their diagnostic approach in patients with prolonged, unexplained fevers meeting the definition of FUO. The present study was undertaken to examine the etiologies, clinico-epidemiologic profile, and prognosis of classical FUO in patients reporting to the Alexandria Fever Hospital in Egypt. Records of 979 patients admitted to the fever hospital (from January 2009 to January 2010) and diagnosed as having FUO were examined carefully. FUO was defined as three outpatient visits or three days in the hospital without elucidation of cause of fever. A total of 979 cases (57.0% males and 43.0% females), with ages ranging from 0.2 to 90 years, were investigated. The mean duration of fever before hospitalization was 31 ± 10 days. The etiology of FUO was delineated in 97% of cases, and only 3% remained undiagnosed. Diagnoses were grouped into five major categories. Infectious causes of FUO were strongly associated with better outcome (73.7% improved). Smoking, contact with animals or birds, drug addiction, and HIV seropositivity were important risk factors associated with infections. Infections are the most common cause of FUO, followed by collagen vascular diseases, in our region. A three-step diagnostic work-up approach is recommended to be applied in Egypt in order to improve the quality of medical service provided to FUO patients.

Fever of unknown origin (FUO): Evolution of case definition, changing aetiological spectrum

Prolonged fever is a common problem faced by clinicians in everyday practise. Since the first description of the entity “fever of unexplained origin” by Petersdorf and Beeson in 1961, the case definition of this entity was further refined with modifications over the last 55 years. Durack and Street proposed noteworthy changes in the definition of “fever of unknown origin (FUO)”. First, they divided FUO into four groups, namely, classic, nosocomial, human immunodeficiency virus (HIV) related and neutropenic FUO. They also proposed a change in the time frame from “one week hospital study” to “three outpatient visits or three days of in-hospital investigations”. The more recent definition modified the temperature recording of above 38.3 °C (101 °F) on “several occasions” to “at least two occasions” and has listed the minimum essential laboratory testing required for diagnosis. The last five decades have also witnessed a change in the aetiological spectrum of FUO. Infectious diseases like tuberculosis are still common causes of FUO in India; an increase in non-infectious causes of FUO are increasingly being documented in studies form the west. Inspite of great advances in imaging and laboratory diagnostic methods a significant number of patients with FUO remained undiagnosed. Studies from other parts of the world have shown 9%-78% cases of FUO to remain undiagnosed while studies from India have shown this figure to be 0%-27.4%. Generating reliable epidemiological data regarding the aetiological spectrum of FUO will facilitate development of optimal work-up strategy to establish the aetiological diagnosis and facilitate the specific tests.

Clinical approach to fever of unknown origin in children.

Fever of unknown origin (FUO) can be caused by many clinical conditions and remains a diagnostic challenge in clinical practice. The etiology of FUO varies markedly among different age groups, geographic areas, and seasons. A four-stage investigative protocol for FUO is widely applied in clinical practice. The aim of this study was to evaluate the usefulness of this four-stage protocol for identifying the etiology of FUO in children. We enrolled children younger than 18 years of age who were admitted to the Taichung Veterans General Hospital during the period from January 2006 to December 2014 with FUO persisting for more than 3 weeks. The four-stage FUO investigative guideline was used to evaluate the etiology of fever in all patients enrolled in the study. The etiology of FUO was identified in 79 (84.9%) of the 93 patients enrolled in the study. The most common cause of FUO was infectious disease (37.6%), followed by malignancy (17.2%), miscellaneous disease (16.1%), and collagen vascular disease (14.0%). With respect to the four-stage survey of FUO, 36 of the 79 patients (45.6%) were identified in Stage 3, 28 patients (35.4%) in Stage 2, 13 patients (16.5%) in Stage 4, and only two patients (2.5%) in Stage 1. A well-designed systemic review of the epidemiological information, medical history, physical examination, laboratory analysis, and adequate invasive procedures provide adequate data to identify the most common causes of FUO in children.

Fever of unknown origin in children: A challenge persisting with advancing medical care

Although huge advances have been made in the field of medicine, fever of unknown origin (FUO) continues to be a significant health problem and an important cause of morbidity and mortality, especially in children. The aim of this study was to study current spectrum of FUO, newly emerging challenges and outcome of FUO. A prospective observational study was conducted over a 16 month period (May 2012-September 2013). 53 children aged 4 months to 15 years met the definition of FUO and were included. Children with known immunodeficiency disorders or other chronic disorders were excluded. A diagnosis was reached in 47 (88.7%) patients. Infections were the commonest cause accounting for FUO in 37 (69.8%) patients. Haematological disorders were found in 8 (15%) and autoimmune diseases in 2 (3.8%) patients. Among infections, the most common causes of FUO were tuberculosis (TB) (37.8%), enteric fever (29.7%), Epstein-Barr virus (EBV) (8.1%) and brucellosis (8.1%). TB was extra-pulmonary in 11 cases and pulmonary in 3 cases. Amongst the haematological disorders, 3 patients had haemophagocytic lymphohistiocytosis (HLH), 3 had leukemia, 1 had non-Hodgkin lymphoma and 1 had autoimmune lymphoproliferative syndrome. Juvenile idiopathic arthritis with systemic onset and polyarteritis nodosa accounted for the two cases of autoimmune disease. Elevated C-reactive protein (CRP) levels were associated with an infectious etiology. Bone tenderness, thrombocytopenia and neutropenia predicted haematological malignancy. 1 patient of HLH died of complications during initial hospitalization and 3 other patients (1 HIV, 2 TB) died on follow up. TB, especially extrapulmonary, and enteric fever are still significant public health problems and were the commonest causes of FUO in our population. Due to advances in diagnostic facilities, some diseases like urinary tract infection (UTI) and hepatitis have become less common; however, other diseases like EBV have become more common causes of FUO. HLH is emerging as a significant cause of morbidity and mortality in FUO patients.

Fever in Children and Fever of Unknown Origin.

Fever is the most common symptom in children and can be classified as fever with or without focus. Fever without focus can be less than 7 d and is subclassified as fever without localizing signs and fever of unknown origin (FUO). FUO is defined as a temperature greater than 38.3 °C, for more than 3 wk or failure to reach a diagnosis after 1 wk of inpatient investigations. The most common causes of FUO in children are infections, connective tissue disorders and neoplasms. Infectious diseases most commonly implicated in children with FUO are salmonellosis, tuberculosis, malaria and rickettsial diseases. Juvenile rheumatic arthritis is the connective tissue disease frequently associated with FUO. Malignancy is the third largest group responsible for FUO in children. Diagnostic approach of FUO includes detailed history and examination supported with investigations. Age, history of contact, exposure to wild animals and medications should be noted. Examination should include, apart from general appearance, presence of sweating, rashes, tonsillitis, sinusitis and lymph node enlargement. Other signs such as abdominal tenderness and hepatosplenomegly should be looked for. The muscles and bones should be carefully examined for connective tissue disorders. Complete blood count, blood smear examination and level of acute phase reactants should be part of initial investigations. Radiological imaging is useful aid in diagnosing FUO. Trials of antimicrobial agents should not be given as they can obscure the diagnosis of the disease in FUO.