Prolonged fever of unknown origin: a record of experiences with 54 childhood patients

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.

FDG PET in Evaluation of Patients With Fever of Unknown Origin: AJR Expert Panel Narrative Review

Fever of unknown origin (FUO) is a diagnostic challenge, with its cause remaining undiagnosed in approximately half of patients. Nuclear medicine tests typically are performed after a negative or inconclusive initial workup. Gallium-67 citrate and labeled leukocytes were previous mainstays of radionuclide imaging for FUO, although they had limited diagnostic performance. FDG PET/CT has subsequently emerged as the nuclear medicine imaging test of choice, supported by a growing volume of evidence. A positive FDG PET/CT result contributes useful information by identifying potential causes of fever, localizing sites for further evaluation, and guiding further management; a negative result contributes useful information by excluding focal disease as the cause of fever and predicts a favorable prognosis. In 2021, CMS rescinded a prior national noncoverage determination for FDG PET for infection and inflammation, leading to increasing national utilization of FDG PET/CT for FUO workup. This article reviews the current status of the role of FDG PET/CT in the evaluation of patients with FUO. The literature reporting the diagnostic performance and yield of FDG PET/CT in FUO workup is summarized, with comparison with historically used nuclear medicine tests included. Attention is also given to the test's clinical impact; protocol, cost, and radiation considerations; and application in children.

Pediatric Hemophagocytic Lymphohistiocytosis: Formation of an Interdisciplinary HLH Working Group at a Single Institution

Fever of unknown origin is a common presentation in children with an extensive differential diagnosis that encompasses multiple specialties. From a hematologic standpoint, the differential includes hyperinflammatory syndrome, such as hemophagocytic lymphohistiocytosis (HLH), among others. Due to the rarity of HLH and nonspecific symptoms at initial presentation, specialists are often consulted later in the disease progression, which complicates disease evaluation further. Cook Children's Medical Center (CCMC) has recently developed a multidisciplinary histiocytic disorder group that is often consulted on cases presenting with fever of unknown origin to increase awareness and potentially not miss new HLH cases. In this study, we examine the clinical presentation and workup of 13 patients consulted by the HLH work group at a single institution and describe the clinical course of 2 patients diagnosed with HLH. The goal of this project was to describe the formation of a disease-specific team and the development of a stepwise diagnostic approach to HLH. A review of the current diagnostic criteria for HLH may be warranted given findings of markers such as soluble IL2 receptor and ferritin as nonspecific and spanning multiple disciplines including rheumatology, infectious disease, and hematology/oncology.

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.

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.

Evaluation of Prolonged and Recurrent Unexplained Fevers

Fever is a common symptom in children. Some children may present to their primary care physician with undifferentiated fever; that is, fever for which there is no obvious source from the history or physical examination. Undifferentiated fevers may be prolonged or recurrent. Distinguishing between the two is helpful for narrowing the differential diagnosis, which can be broad and include infections and inflammatory diseases and, rarely, malignancies and autoinflammatory disorders. The evaluation of such children requires a step-wise approach. Taking a detailed history, performing a thorough physical examination, and reviewing a fever and symptom diary is crucial in recognizing clues that may ultimately lead to a diagnosis. Some children who look good and whose fever disappears may never have a diagnosis, whereas referral to a specialist may be prudent for others. [Pediatr Ann. 2018;47(9):e347-e353.].

Characteristics of Patients Referred to a Pediatric Infectious Diseases Clinic With Unexplained Fever

BACKGROUND

Older case series established diagnostic considerations for children meeting a priori definitions of fever of unknown origin (FUO). No recent study has examined the final diagnoses of children referred for unexplained fever.

METHODS

This study was conducted with a retrospective chart review of patients referred to a pediatric infectious diseases clinic from 2008 to 2012 for unexplained fever.

RESULTS

Sixty-nine of 221 patients were referred for "prolonged" unexplained fever. Ten of these were not actually having fever, and 11 had diagnoses that were readily apparent at the initial visit. The remaining 48 were classified as having FUO. The median duration of reported fever for these patients was 30 days; 15 had a diagnosis made, 5 of which were serious. None of the serious FUO diagnoses were infections. Of 152 patients with "recurrent" unexplained fever, 92 had an "intermittent" fever pattern, and most of these had sequential, self-limited viral illnesses or no definitive diagnosis made. Twenty of the 60 patients with a "periodic" fever pattern were diagnosed with periodic fever, aphthous stomatitis, pharyngitis, and adenitis syndrome. Overall, 166 patients either were not having fever, had self-limited illnesses, or ultimately had no cause of fever discovered. Only 12 had a serious illness, 2 of which were infections (malaria and typhoid fever).

CONCLUSIONS

Most children referred with unexplained fever had either self-limited illnesses or no specific diagnosis established. Serious diagnoses were unusual, suggesting that these diagnoses rarely present with unexplained fever alone, or that, when they do, the diagnoses are made by primary care providers or other subspecialists.

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.

Prolonged and recurrent fevers in children

Some children referred for prolonged fever are actually not having elevated temperatures; the approach here requires dissection of the history and correction of health misperceptions. Others have well-documented fevers associated with clinical, laboratory, or epidemiologic findings that should point to a specific diagnosis. "Fever-of-Unknown-Origin" (FUO) is the clinical scenario of daily fever for ≥ 14 days that defies explanation after a careful history, physical examination, and basic laboratory tests. The diagnostic approach requires a meticulous fever diary, serial clinical and laboratory evaluations, vigilance for the appearance of new signs and symptoms, and targeted investigations; the pace of the work-up is determined by the severity of the illness. Approximately half of children with FUO will have a self-limited illness and will never have a specific diagnosis made; the other half will ultimately be found to have, in order, infectious, inflammatory, or neoplastic conditions. Irregular, intermittent, recurrent fevers in the well-appearing child are likely to be sequential viral illnesses. Monogenic autoinflammatory diseases should be considered in those who do not fit the picture of recurrent infections and who do not have hallmarks of immune deficiency. Stereotypical febrile illnesses that recur with clockwork periodicity should raise the possibilities of cyclic neutropenia, if the cycle is approximately 21 days, or periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome, the most common periodic fever in childhood.

Fever of unknown origin in children: a systematic review

BACKGROUND

there are no previous systematic reviews of published pediatric case series describing the etiology of fever of unknown origin (FUO). The purpose of collecting these data is to determine the etiologies for children with FUO in both developing and developed countries.

METHODS

the database Ovid Medline R (1950 to August 2009 week 4) and Ovid Embase (1980 to 2010 week 2) were used to conduct the search. Studies in any language were included if they provided the diagnosis in a series of 10 or more children with FUO. The diagnosis of each child at the time of publication of the study was recorded.

RESULTS

there were 18 studies that met the inclusion criteria, describing 1638 children. The diagnosis at the time of publication was malignancy for 93 children (6%), collagen vascular disease for 150 (9%), miscellaneous non-infectious conditions for 179 (11%), infection for 832 (51%), and no diagnosis for 384 (23%). There were 491 bacterial infections (59% of all infections) with common diagnoses being brucellosis, tuberculosis, and typhoid fever in developing countries, osteomyelitis, tuberculosis, and Bartonellosis in developed countries, and urinary tract infections in both. For children with no diagnosis after investigations, most had fever that ultimately resolved with no sequelae.

CONCLUSIONS

about half of FUOs in published case series are ultimately shown to be due to infections with collagen vascular disease and malignancy also being common diagnoses. However, there is such a wide variety of possibilities that investigations should primarily be driven by the clinical story.

Brucellosis as a cause of fever of unknown origin in children admitted to a tertiary hospital in the Aegean region of Turkey

The aim of the study was to determine the role of brucellosis in children with fever of unknown origin (FUO) in the Aegean region of Turkey. For this purpose, the records of all children referred or admitted with diagnosis of FUO to the Department of Pediatric Infectious Diseases, Ege University Medical School, between 2003 and 2008 were scanned and 92 cases were identified retrospectively. Fifty-eight of these 92 children (63%) were diagnosed with infectious diseases, brucellosis being the most frequent cause (15.2%). Although several other infectious diseases do appear as a cause of FUO, brucellosis should be particularly considered as a differential diagnosis.

Fever of unknown origin: a diagnostic approach to this vexing problem

Fever is a common complaint leading families to seek medical attention. Its routine management is the bread and butter of pediatric practice. When fever is seen as prolonged beyond the expected time course (eg, 10 days for a presumed viral respiratory tract infection or 3 weeks for mononucleosis), concern for fever of unknown origin (FUO) may ensue. This diagnosis is among the most challenging for health care providers to approach and often involves referral to subspecialists. Generally, the pace of the evaluation should be guided by the severity of the disease, rather than the anxiety of the family or of the health care providers. It is useful to recognize that uncommon manifestations of common diseases are more likely than are rare diseases. Furthermore, clues to the diagnosis are frequently present in the history and physical examination but are not elicited or unappreciated (perhaps due to time constraints). Therefore, thoroughness and repetition are vitally important. Although the differential diagnosis of FUO is vast, a thoughtful, focused approach based on information gleaned from a thorough history and physical examination (together with any laboratory or other study results) is preferable to a "shotgun" or "running the list" one. Finally, FUO in special populations, including children in the hospital, those with HIV infection or other immunocompromise, and those in the developing world, require special consideration. Most children do well, compared to adults with FUO, but true FUO is not always a benign condition, necessitating the best care a health care provider can offer.

Clinical spectrum of fever of unknown origin among Indian children

BACKGROUND

Fever of unknown origin (FUO) is an important cause of morbidity and mortality in children, especially in tropical and developing countries.

AIM

To determine the aetiology and outcome of FUO in Indian children.

METHODS

A hospital-based, prospective, observational study was conducted over a 1-year period (2006-2007). Children aged > or =3 months to 12 years who qualified for the definition of FUO were recruited. Initial evaluation included complete blood count, peripheral smear for malarial parasites, erythrocyte sedimentation rate (ESR), urine analysis and culture, blood culture, tuberculin test and chest X-ray.

RESULTS

Of 49 patients evaluated, a diagnosis was reached in 43 (88%). Infections were the predominant cause of FUO in 34 patients (69%). Enteric fever was the most common infection (14), followed by visceral leishmaniasis (10) and tuberculosis (5). The next most common cause was malignancy (6, 12%). Among the six undiagnosed patients, spontaneous resolution occurred in five whereas one child continued to be febrile without an established cause at the end of the study.

CONCLUSION

Repeated, thorough clinical examination and carefully selected laboratory examinations proved useful in the diagnosis of FUO. Serology (e.g. enteric fever) and bone marrow examination (e.g. leishmaniasis, malignancy) were the most useful diagnostic tests.

Fever of unknown origin in 185 paediatric patients: a single-centre experience

AIM

We conducted a prospective study to evaluate the causes and outcome in children with fever of unknown origin (FUO).

METHODS

From 1990 to 1999, 185 children with FUO were evaluated. Initial evaluation included routine haematological analysis, Epstein-Barr virus (EBV) serology, urine, stool or blood cultures, chest X-ray and tuberculin probe.

RESULTS

In 131 (70%) patients diagnosis was established, and 70 (37.8%) had infectious disease. EBV infection was the most common infection followed by visceral leishmaniasis (VL), urinary tract infection (UTI) and tuberculosis. Autoimmune disorders were diagnosed in 24 (12.9%), Kawasaki disease in 12 (6.4%), malignant diseases in 12 (6.4%) and miscellaneous conditions in 15 (8.1%) patients. In the remaining 54 (30%) patients, diagnosis was not established and most of them had self-limited disease. During the investigation, 26 (14%) patients developed serious organ dysfunction and five patients (two with virus-associated haemophagocytic syndrome, one with VL and two unknown) died.

CONCLUSION

The most important infectious causes of FUO in our study were EBV infection and VL. Kawasaki disease represented a significant cause of FUO at the beginning of our study because it was not recognized by primary-care physicians. We report myelodysplastic syndrome as another emerging cause of paediatric FUO. Repeated clinical examination and careful use of specific laboratory examinations, invasive diagnostic procedures or imaging are crucial in approaching paediatric FUO.

[Noninfectious febrile inflammatory syndromes in children: diagnosis and usefulness of diagnostic procedures]

OBJECTIVE

To determine the causes and to quantify the benefits obtained from further diagnostic investigations in children presenting with a non infectious inflammatory fever.

METHODS

The records of 62 children aged from two-months to 15 years (median: four years) admitted to a paediatric department between 1990 and 2000 for the evaluation of a fever associated to an inflammatory syndrome, defined as temperature over 38 degrees C with an increase of the erythrocyte sedimentation rate (ESR) more than 20 mm/h and/or a serum C-reactive protein level (CRP) > 20 mg/L, and excluding overt infectious diseases, were retrospectively reviewed.

RESULTS

Of these patients, 79% children (49 cases) had inflammatory systemic disease, 3.2% (two cases) had malignancy, and 17.8% (11 cases) had undiagnosed disorders. The most frequent disease was Kawasaki disease (22 children), especially in young children. Increase of ESR above 100 mm/h and of CRP above 100 mg/L was present in 59% of Kawasaki disease, 71% of idiopathic juvenile arthritis, 100% of malignancies and 7% of unknown diagnoses. Increase of ESR below 50 mm/h and of CRP below 50 mg/L was present in 75% of hemophagocytic syndromes and 46% of unknown diagnosis. The polymorphonuclear count, hepatic function evaluation, triglycerides levels, abdominal ultrasound, abdominal computed tomography, echocardiography, biopsies were useful diagnosis tools. Technetium scintigraphy was helpful only when abnormalities were found on physical examination.

CONCLUSION

The diagnosis of Kawasaki disease must be quickly suspected in febrile young children with inflammatory syndrome without infection. ESR and CRP values, abdominal ultrasound and echocardiography are helpful tools for the diagnostic procedure.

Management of children with prolonged fever of unknown origin and difficulties in the management of fever of unknown origin in children in developing countries

This is Part II of a 2-part paper on fever of unknown origin (FUO) in children. It examines the aetiology and management of prolonged FUO in children and the difficulties in the management of FUO in children in developing countries. Part I of this paper discussed acute FUO in children and was published in the March 2001 issue of Paediatric Drugs. Prolonged FUO is documented fever of more than 7 to 10 days which has no apparent source and no apparent diagnosis after 1 week of clinical investigations. About 34% of cases of prolonged FUO are caused by infections, with bacterial meningitis and urinary tract infection accounting for about 6.5 and 11.4%, respectively, of cases attributable to infections. Chronic infections, particularly tuberculosis and 'old' disorders such as Kawasaki disease, cat-scratch disease and Epstein-Barr virus infection presenting with 'new' manifestations, collagen-vascular diseases and neoplastic disorders are the other issues of major concern in prolonged FUO. Overall, however, there is a trend towards an increased number of undiagnosed cases. This is due to advancements in diagnostic techniques, such that illnesses which were previously common among the causes of prolonged FUO are now diagnosed earlier, before the presentation becomes that of prolonged FUO. Clinical examination supplemented with laboratory tests to screen for serious bacterial infections should be the mainstay of initial evaluation of children with prolonged FUO. Use of scanning techniques (such as computerised tomography and ultrasound) as additional supplements to this clinical examination may allow for the earlier diagnosis of causes of prolonged FUO in children such as 'occult' abdominal tumours. A common error in management of children with prolonged FUO is the failure to perform a complete history and physical examination; repeated clinical examination and continued observation are of paramount importance in the diagnosis of difficult cases. Major difficulties in the management of FUO in children in developing countries include constraints in the availability and reliability of laboratory tests, cost, misuse of antibiotics and difficulties encountered in the diagnosis of malaria and typhoid fever. Malaria and typhoid fever are major aetiological considerations in both acute and prolonged FUO in children in developing countries. The newer quinolones may hold great promise for the treatment of serious bacterial infections, including meningitis, which are associated with prolonged FUO in developing countries.

Aetiology and management of children with acute fever of unknown origin

This is part I of a 2-part paper on fever of unknown origin (FUO) in children. FUO is best defined as fever without obvious source on initial clinical examination and then classified into acute (illness of < or =1 week's duration) and prolonged (>7 to 10 days' duration). Aetiologically, there is a marked overlap between acute and prolonged FUO, and infections are major players in both. Age, climate, local epidemiology and host factors are the major aetiological factors that should be considered in the choice of definitive tests. Depending on age, serious bacterial infections (including bacteraemia, meningitis and urinary tract infection) occur in 3 to 20% of cases of acute FUO. Prevention of mortality and sequelae from these infections, particularly bacteraemia and meningitis, is of particular concern in acute FUO. An individualised approach, based on clinical evaluation supplemented with screening and definitive laboratory tests to determine the need for empiric antibiotic therapy and hospitalisation, seems to be the best approach to acute FUO (although this may be less applicable to neonates and infants younger than 90 days, particularly those aged 0 to 7 days). The place of laboratory tests, empiric antibiotic therapy and hospitalisation are important issues that are likely to remain so for some time.

Differential diagnosis of fever of unknown origin in children

Fever of unknown origin in children follows two main clinical patterns, namely fever of unknown origin and chronic episodic fever of unknown origin. Fever of unknown origin is characterized by daily fever persisting for more than 3 weeks. The main causes are infectious, rheumatologic disorders, and malignancy. Chronic episodic fever of unknown origin is characterized by fever lasting for a few days to a few weeks, followed by a fever-free interval and a sense of well-being. The main causes are familial Mediterranean fever, the hyper-immunoglobulin D syndrome, familial Hibernian fever, Behcet disease, the syndrome of periodic fever, aphthous stomatitis, pharyngitis and adenitis, and cyclic neutropenia.

[Management of prolonged fever in infants]

Prolonged fever is defined as an unexplained fever of more than 5 days duration. In infancy and early childhood, it is most often of infectious origin, viral infections being the most frequent. Mycoplasma pneumoniae infections, urinary tract infection and otitis media are also commonly involved. Kawasaki disease is the main inflammatory etiology, juvenile rhumatoïd arthritis in its systemic form (Still's disease) being much rarer. In most cases the etiological diagnosis can be made with a limited number of laboratory and/or imaging investigations based upon a careful clinical evaluation and an oriented chronological strategy.

Fever of unknown origin in childhood: difficulties in diagnosis

We have described a child with systemic onset juvenile chronic arthritis who presented initially with fever of unknown origin. Treatment of a presumed infection led to a severe allergic response with Stevens-Johnson syndrome, renal failure and DIC. This reaction obscured the features of the underlying disease and delayed the diagnosis.

Gallium scanning in children with fever of unknown origin

Scintigraphy with Gallium 67 is frequently used in the evaluation of children with fever of unknown origin (FUO). Its usefulness in this setting, however, has not been definitely established. We reviewed the clinical records and imaging studies of 30 children with FUO who had Gallium scans. We defined FUO as a febrile illness of greater than two weeks duration which remained undiagnosed after initial clinical, laboratory and radiographic evaluation. 4 of 30 children had positive Gallium scans. Of 25 children with only systemic signs and symptoms in addition to fever, 1 had a positive scan. Of 5 children with more focal complaints, 3 had positive studies: all had localized infections which had remained occult despite imaging with other modalities. We conclude that in most children with FUO, who have only systemic complaints, Gallium scanning is rarely useful. It may be very helpful, however, when there is a suspicion of localized infection, even if other imaging studies are negative.

Usefulness of scanning procedures for diagnosis of fever of unknown origin in children

During a 5-year study period, 109 patients were referred to a large children's hospital for evaluation of prolonged fever of unknown origin, defined as temperature greater than or equal to 38 degrees C (100.4 degrees F) for 3 weeks or longer and negative findings on initial examination. A two-phase protocol of outpatient followed by inpatient diagnostic studies was instituted for most patients. Confirmed diagnoses were achieved in just 36 of these children (33%) in the following disease categories: infectious, 24 (22%); autoimmune, 7 (6%); and neoplastic, 2 (2%). Scanning or special procedures and the number with positive results (in parentheses) were as follows: abdominal ultrasonography, 43 (8); abdominal computed tomography, 14 (3); indium scan 11 (5); gallium scanning, 4 (1), upper gastrointestinal tract series, 13 (2); technetium bone scanning 15 (2); bone marrow examination, 16 (1); and cranial computed tomography, 7 (0). These studies rarely led to an unsuspected diagnosis. It appears most appropriate in evaluating fever of unknown origin in children to obtain only basic laboratory studies such as a complete blood cell count, urinalysis and culture, chest radiograph, tuberculin skin test, and, in the older child, an antinuclear antibody titer. When these test results are negative, almost all children can be observed clinically for progression of illness or a focus that might then direct specific diagnostic procedures.

Primary macronodular hepatic tuberculosis: US and CT appearances

Tuberculosis of the liver is uncommon except in association with miliary dissemination. Although hepatic involvement by tuberculosis tends to be diffuse, the macronodular or pseudotumor forms are rare. In addition, reports of actual imaging of tuberculous liver involvement are rare. A 5-year-old boy with a febrile illness due to macronodular hepatic tuberculosis, demonstrated by abdominal computed tomography (CT), and diagnosed by liver biopsy is presented.

Prolonged unexplained pyrexia: a review of 221 paediatric cases from Kuwait

Over a three year period (January 1985 through December 1987), 221 children with prolonged pyrexia were admitted to the paediatric departments in two regional hospitals in Kuwait. Infections, connective tissue diseases and malignancies constituted 78%, 5% and 2%, respectively, and 15% of the cases remained undiagnosed. Brucella was the most common infectious agent encountered (38% of all cases), followed by typhoid fever (9%). The duration of fever was more helpful in the differential diagnosis than its height or pattern. The erythrocyte sedimentation rate and the white blood count were of limited value, and the C-reactive protein was positive in bacterial infections, malignancies and connective tissue diseases. Since a child presenting with prolonged pyrexia in this country has over a 70% chance of having a bacterial infection, both diagnostic and therapeutic procedures should be performed as an emergency measure. Particular emphasis should be put on the exclusion of brucellosis.