title: Fever of unknown origin in the outpatient setting: A retrospective analysis of 30 cases of familial Mediterranean fever.
abstract: In Japan, familial Mediterranean fever (FMF) is a rare cause of fever of unknown origin (FUO). However, we experienced an extraordinary number of FMF cases over 3 years. This suggests that many patients with FMF remain misdiagnosed in Japan. This study examines the clinical picture of FMF to assist Japanese clinicians in daily practice dealing with FUO.
  
  
  
  Three years of medical records were reviewed, and 38 patients with FMF or suspected FMF were collected from our patient database. We applied the Tel-Hashomer criteria to those patients.
  
  
  
  Of the 38 patients, 30 were classified as having FMF in this investigation. The mean patient age was 27.8 years. MEFV gene mutations were detected in 14 patients. Three cases were colchicine-resistant.
  
  
  
  Clinicians should recognize the pattern of short, spontaneously resolving attacks of fever with fever-free intervals, especially when they see patients with recurrent FUO in the outpatient setting.
authors.affiliation: Department of General Internal Medicine, National Center for Global Health and Medicine Hospital.
authors.forename: Junwa
authors.initials: J
authors.lastname: Kunimatsu
authors.forename: Junko
authors.initials: J
authors.lastname: Maeda
authors.forename: Riri
authors.initials: R
authors.lastname: Watanabe
authors.forename: On
authors.initials: O
authors.lastname: Kato
authors.forename: Dai
authors.initials: D
authors.lastname: Kishida
authors.forename: Masahide
authors.initials: M
authors.lastname: Yazaki
authors.forename: Akinori
authors.initials: A
authors.lastname: Nakamura
mesh_terms: D000293:Adolescent; D000328:Adult; D003078:Colchicine; D004351:Drug Resistance; D010505:Familial Mediterranean Fever / Q000150:complications* / Q000175:diagnosis / Q000235:genetics; D005260:Female; D005335:Fever of Unknown Origin / Q000209:etiology*; D005820:Genetic Testing; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010045:Outpatients; D000071198:Pyrin / Q000235:genetics; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: C000604192:MEFV protein, human; D000071198:Pyrin; D003078:Colchicine