title: Acute suppurative oligoarthritis and osteomyelitis: a differential diagnosis that overlaps with acute rheumatic fever.
abstract: BACKGROUND
  Acute rheumatic fever (ARF) is an illness caused by group A streptococcus (GAS) infection, and remains the leading cause of acquired heart disease in worldwide. Distinguishing between ARF and septic arthritis may be difficult. This report describes a case of suppurative arthritis overlapping with ARF.
  
  
  METHODS
  A 4-year-old, previously healthy boy presented with fever and left leg pain. The level of anti-streptolysin O (ASO) was elevated. His throat swab cultures grew GAS, but none were detected in his synovial fluid. Magnetic resonance imaging revealed suspected arthritis and osteomyelitis. The patient was treated for septic arthritis, but was subsequently diagnosed with ARF, after the development of carditis.
  
  
  CONCLUSIONS
  The clinical and laboratory features of ARF and suppurative arthritis demonstrate substantial overlap. Patients with an elevated ASO should undergo a careful cardiac examination for carditis associated with ARF by an echocardiogram.
authors.affiliation: Department of Pediatrics, Tokyo Medical University, Tokyo, Japan. Electronic address: sato115@tokyo-med.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sato
authors.affiliation: Department of Pediatrics, Tokyo Medical University, Tokyo, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Chiyotanda
authors.affiliation: Department of Pediatrics, Tokyo Medical University, Tokyo, Japan.
authors.forename: Tae
authors.initials: T
authors.lastname: Hijikata
authors.affiliation: Department of Pediatrics, Tokyo Medical University, Tokyo, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ishida
authors.affiliation: Department of Pediatrics, Tokyo Medical University, Tokyo, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Oana
authors.affiliation: Department of Pediatrics, Tokyo Medical University, Tokyo, Japan.
authors.forename: Gaku
authors.initials: G
authors.lastname: Yamanaka
authors.affiliation: Department of Pediatrics, Tokyo Medical University, Tokyo, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Kawashima
authors.affiliation: Department of Orthopedics, Tokyo Medical University, Tokyo, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Kubo
mesh_terms: D000208:Acute Disease; D001170:Arthritis, Infectious / Q000175:diagnosis* / Q000382:microbiology; D001171:Arthritis, Juvenile / Q000175:diagnosis* / Q000382:microbiology; D002675:Child, Preschool; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D009205:Myocarditis / Q000382:microbiology; D010019:Osteomyelitis / Q000175:diagnosis* / Q000382:microbiology; D012213:Rheumatic Fever / Q000175:diagnosis* / Q000188:drug therapy* / Q000382:microbiology; D013290:Streptococcal Infections / Q000150:complications* / Q000188:drug therapy; D013297:Streptococcus pyogenes / Q000302:isolation & purification*
keywords: Acute rheumatic fever; Arthritis; Monoarthritis; Osteomyelitis; Rheumatic heart disease