ORIGINAL ARTICLE Kikuchi-Fujimoto disease in children Shoba N Selvanathan , 1 Sharline Suhumaran, 2 Vinay K Sahu, 1,3,4,5 Chia Yin Chong , 3,4,5,6 Natalie Woon Hui Tan 3,4,5,6 and Koh Cheng Thoon 4,5,6 Departments of 1 Paediatric Medicine, and 2 Child Development, and 6 Infectious Disease Service, Department of Paediatrics, KK Women’s and Children’s Hospital, 3 Duke-NUS Graduate School of Medicine, and 4 Yong Loo Lin School of Medicine, National University of Singapore and 5 Lee Kong Chian School of Medicine, National Technological University, Singapore 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 devel- oping systemic lupus erythematosus. We recommend that patients be followed up for recurrence and advised to monitor for symptoms of recurrence. Key words: children; histiocytic necrotising lymphadenitis; Kikuchi’s disease; lymphadenitis; paediatric. What is already known on this topic 1 Kikuchi-Fujimoto disease (KFD) is an important cause of lymphad- enitis in children. Although generally benign, symptoms can be prolonged and complications such as haemophagocytic lympho- histiocytosis have been reported. 2 Studies on KFD have generally been small with a reported recur- rence rate of 3–4% and up to 42.4% in the paediatric population. 3 KFD has been associated with systemic lupus erythematosus. What this paper adds 1 Our study shows that Kikuchi disease in children has a male predominance, different from that seen in adults. 2 We report a recurrence rate of 12.2%, with one patient who developed systemic lupus erythematosus. Recurrent cases were more likely to be managed as an inpatient and have fever at pre- sentation of their first episode of KFD. 3 Carers should be informed of the risk of recurrence. Kikuchi-Fujimoto disease (KFD), also known as histiocytic necro- tising lymphadenitis, is generally a benign self-limited disease of unknown aetiology characterised by fever and cervical lymph- adenopathy. 1,2 Systemic changes are more likely with extranodal involvement and include night sweats, chills, weight loss, gener- alised lymphadenopathy, arthralgia, rash and neurological involvement. 3–5 Although most patients have a benign course, symptoms can be prolonged and complications such as haemophagocytic lymphohistiocytosis have been reported. 3,5 As the symptoms are non-specific, differential diagnoses such as viral infections (Epstein–Barr virus, cytomegalovirus), malignancies such as lymphoma and autoimmune conditions such as systemic lupus erythematosus (SLE) are often considered. Laboratory and clinical findings are non-specific and a lymph node biopsy is necessary for histopathological diagnosis. KFD has a reported recurrence rate of 3–4%. 6 Paediatric stud- ies have shown a higher recurrence rate of up to 42.4%. 5,7–12 There have also been reports of progression to SLE. 1,13–15 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 <18 years old who were diagnosed with KFD from January 2000 to September 2017 at KK Women’s and Children’s Hospital, the largest paediatric hos- pital in Singapore. KK Women’s and Children’s Hospital is an Correspondence: Dr Shoba N Selvanathan, KK Women’s and Children’s Hospital, 100 Bukit Timah Road, Singapore 229899. Fax: +65 6291 7923; email: shoba.nanthini.selvanathan@singhealth.com.sg Conflict of interest: None declared. Accepted for publication 1 September 2019. doi:10.1111/jpc.14628 Journal of Paediatrics and Child Health (2019) © 2019 Paediatrics and Child Health Division (The Royal Australasian College of Physicians) 1