Kikuchi-Fujimoto disease in children: two case reports and a review of the literature

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 (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.

Clinical Analysis of 44 Children with Subacute Necrotizing Lymphadenitis

Objective

Methods

Results

Conclusion

Kikuchi-Fujimoto Disease Following COVID-19

Kikuchi-Fujimoto Disease (KFD) is a rare self-limiting condition of unknown etiology. It is characterized by fever, and lymphadenopathy most commonly involving posterior cervical lymph nodes. Although it is of uncertain etiology, it is associated with viral infections and autoimmune diseases. Distinction from lymphadenopathy-associated alternate disorders is crucial to avoid unneeded diagnostic procedures and treatment. KFD is diagnosed based on histopathologic examination of the excised lymph node. The management is supportive with favorable outcomes within a few weeks or months. In this case, we describe a 13-year-old boy who complained of painful cervical lymphadenopathy and fever for more than three weeks following COVID-19. Diagnostic workup has been established and KFD diagnosis made based on the histopathologic features of the involved lymph node. The patient showed complete recovery with no recurrence during follow-up. So, this case highlights the possible association between COVID-19 and KFD during this pandemic and keeping it in the differential diagnosis.

COVID-19 in a case with Kikuchi-Fujimoto disease

The accurate diagnosis of Kikuchi-Fujimoto disease can protect children from unnecessary diagnostic procedures and treatments. Also, the co-occurrence of rare diseases with other diseases can improve or worsen the symptoms of the patients.

Hemophagocytic Lymphohistiocytosis Associated with Histiocytic Necrotizing Lymphadenitis: A Clinical Study of 13 Children and Literature Review

OBJECTIVE

To analyze the clinical characteristics and prognosis of pediatric hemophagocytic lymphohistiocytosis (HLH) associated with histiocytic necrotizing lymphadenitis (HNL).

STUDY DESIGN

We retrospectively collected the clinical data of all children with HNL-HLH enrolled in Beijing Children's Hospital from 2007 to 2019. The control patients with Epstein-Barr virus-associated HLH and simple HNL (not associated with HLH) were case matched (1:2). The clinical features and prognosis were analyzed by case-control study. Cases of HNL-HLH in the literature were reviewed.

RESULTS

The male-to-female ratio of the 13 patients in our center was 9:4. The mean age of the patients at disease onset was 8.1 ± 1.2 years, younger than that of the 16 patients in the literature (P = .017). Clinical presentations, especially rash and splenomegaly, and laboratory examination of HNL-HLH group were statistically different from Epstein-Barr virus-HLH group, simple HNL group, and patients reported in the literature (P < .05). Three patients were treated with immunosuppressive drugs or chemotherapy owing to poor control of HLH. One patient died, and all 12 remaining patients survived, 2 of which developed autoimmune diseases. Kaplan-Meier survival curves showed no statistical difference among the 3 groups (P > .05).

CONCLUSIONS

HNL-HLH is more common in school- and preschool-age children. Most patients have a favorable prognosis. Some patients suffer from relapses or develop autoimmune diseases. Prolonged follow-up should be carried out for patients with HNL-HLH.

Kikuchi's disease with hemophagocytic lymphohistiocytosis: A case report and literature review

INTRODUCTION

Kikuchi's disease (KD) is a rare form of necrotizing lymphadenitis that rarely occurs in association with hemophagocytic lymphohistiocytosis (HLH) in children.

PATIENT CONCERNS

We report the case of a 4-year-5-month-old boy who suffered from fever, cervical lymphadenopathy, pancytopenia, hypertriglyceridemia, splenomegaly, low NK cell activity.

DIAGNOSES

A diagnosis of KD with HLH was made based on the results of biopsy of cervical lymph node and HLH-2004 trial guidelines.

INTERVENTIONS

The patient was treated with corticosteroids, cyclosporine, etoposide, continuous hemodiafiltration (HDF), and plasma exchange (PE).

OUTCOMES

He showed a complete response to therapy, and his condition gradually improved. He was discharged on day 45 after admission due to his good recovery status.

CONCLUSION

HLH can be associated with KD, especially in childhood, and may have an aggressive clinical course. Continuous HDF and PE and chemotherapy should be reserved for those patients who fail to respond to IVIG and corticosteroids.

Kikuchi-Fujimoto Disease: Review of 11 Cases Diagnosed Over 10 Years at a Tertiary Care Hospital in Doha, Qatar

Introduction

Kikuchi-Fujimoto (KF) disease is a rare and self-limiting disorder of unknown aetiology characterized by cervical lymphadenopathy (CLN) and fever. The pathophysiology remains unclear and may be triggered by an infectious agent leading to a self-limiting autoimmune process. There are no confirmatory laboratory tests and lymph node biopsy is required to differentiate KF disease from other serious conditions.

Materials and methods

We report 11 cases of KF disease diagnosed at Hamad General Hospital, Qatar, between 2006 to 2016. The diagnosis is based on clinical presentation, investigations and histopathological examination of lymph nodes.

Results

All patients had painful neck swelling (average duration of 2.9 weeks) and 10 had fever (average duration of 3.2 weeks). Five patients developed mild leucopenia which resolved completely. HIV and tuberculosis (TB) screening including sputum for AFB, a PPD skin test and chest x-ray was done for all patients and came back negative. Autoimmune screening was done for all patients and excluded any rheumatological disease. Ultrasound and CT of the neck confirmed cervical lymphadenopathy. Except for hepatomegaly in one patient, CT scans of the chest and abdomen were negative for any lymphadenopathy or organomegaly (performed in seven patients). Diagnosis was confirmed on lymph node excision biopsy. Histopathological examination showed findings consistent with the diagnosis of histiocytic necrotizing lymphadenitis (KF disease).

Conclusion

KF disease should be kept in mind for patients presenting with fever and CLN. Lymphoma, TB and autoimmune diseases like systemic lupus erythematosus should be excluded in such patients.

Kikuchi-Fujimoto disease in children

AIM

Kikuchi-Fujimoto disease (KFD) is an important cause of lymphadenitis in children. The primary aim of this study was to investigate the clinical characteristics of children with KFD and to assess the recurrence of this disease.

METHODS

This is a retrospective study of patients younger than 18 years old, who were diagnosed with KFD from January 2000 to September 2017 at KK Women's and Children's Hospital. Records of children with a histological diagnosis of KFD from a lymph node biopsy were obtained from the Department of Pathology. Case notes and electronic medical records of the patients were reviewed. Data collected included patient characteristics, symptoms, clinical and laboratory findings, treatment and follow-up.

RESULTS

A total of 98 patients were identified. There were 52 boys and 46 girls with a median age of 11.2 years old. Recurrence occurred in 12 (12.2%) patients. One patient developed systemic lupus erythematosus 10 years after diagnosis of KFD. Recurrent cases were more likely to be managed as an inpatient and have fever at presentation of their first episode of KFD.

CONCLUSION

In our study, KFD in children had a higher prevalence among boys, and had a recurrence rate of 12.2%, with 1% of patients developing systemic lupus erythematosus. We recommend that patients be followed up for recurrence and advised to monitor for symptoms of recurrence.