title: Arthritis in children: comparison of clinical and biological characteristics of septic arthritis and juvenile idiopathic arthritis.
abstract: OBJECTIVE
  Childhood arthritis arises from several causes. The aim of this observational study is to compare the clinical and biological features and short-term outcome of different types of arthritis because they have different treatment and prognoses.
  
  
  METHODS
  Children <16 years of age hospitalised in a French tertiary care centre for a first episode of arthritis lasting for less than 6 weeks who underwent joint aspiration were retrospectively included. We performed non-parametrical tests to compare groups (septic arthritis (SA), juvenile idiopathic arthritis (JIA) and arthritis with no definitive diagnosis). The time before apyrexia or C reactive protein (CRP) <10 mg/L was analysed using the Kaplan-Meier method.
  
  
  RESULTS
  We studied 125 children with a sex ratio (M/F) of 1.1 and a median age of 2.2 years (range 0.3 to 14.6). SA was associated with a lower age at onset (1.5 years, IQR 1.2-3.0 vs 3.6 years, IQR 2.2-5.6), shorter duration of symptoms before diagnosis (2 days, IQR 1-4 vs 7 days, IQR 1-19) and higher synovial white blood cell count (147 cells ×103/mm3, IQR 71-227, vs 51 cells ×103/mm3, IQR 12-113), than JIA. Apyrexia occurred later in children with JIA (40% after 2 days, 95% CI 17% to 75%) than children with SA (82%, 95% CI 68% to 92%), as did CRP<10 mg/L (18% at 7 days, 95% CI 6.3% to 29.6% vs 82.1%, 95% CI 76.1% to 89.7%, p=0.01).
  
  
  CONCLUSIONS
  There were no sufficiently reliable predictors for differentiating between SA and JIA at onset. The outcomes were different; JIA should be considered in cases of poor disease evolution after antibiotic treatment and joint aspiration.
authors.affiliation: Unité d'Epidémiologie Clinique, AP-HP, Hôpital Robert Debré, Paris, France.|Inserm, U1123, ECEVE and CIC-EC 1426, Paris, France.|Univ Denis Diderot Paris 7, Sorbonne Paris Cité, Paris, France.
authors.forename: Camille
authors.initials: C
authors.lastname: Aupiais
authors.affiliation: Univ Denis Diderot Paris 7, Sorbonne Paris Cité, Paris, France.|Service de Pédiatrie Générale, AP-HP, Hôpital Robert Debré, Paris, France.|Inserm, UMR1137, Infection, Antimicrobials, Modelling, Evolution (IAME), Paris, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Basmaci
authors.affiliation: Univ Denis Diderot Paris 7, Sorbonne Paris Cité, Paris, France.|Service d'Orthopédie Pédiatrique, AP-HP, Hôpital Robert Debré, Paris, France.
authors.forename: Brice
authors.initials: B
authors.lastname: Ilharreborde
authors.affiliation: Département Informatique Médicale, Hôpital Robert Debré (APHP), Paris, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Blachier
authors.affiliation: Service d'Accueil des Urgences Pédiatriques, AP-HP, Hôpital Robert Debré, Paris, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Desmarest
authors.affiliation: Service de Rhumatologie, AP-HP, Hôpital Cochin, Paris, France.|Université René Descartes Paris 5, Paris, France.
authors.forename: Chantal
authors.initials: C
authors.lastname: Job-Deslandre
authors.affiliation: Inserm, U1123, ECEVE and CIC-EC 1426, Paris, France.|Univ Denis Diderot Paris 7, Sorbonne Paris Cité, Paris, France.|Service de Pédiatrie Générale, AP-HP, Hôpital Robert Debré, Paris, France.
authors.forename: Albert
authors.initials: A
authors.lastname: Faye
authors.affiliation: Univ Denis Diderot Paris 7, Sorbonne Paris Cité, Paris, France.|Inserm, UMR1137, Infection, Antimicrobials, Modelling, Evolution (IAME), Paris, France.|Service de Microbiologie, AP-HP, Hôpital Robert Debré, Paris, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bonacorsi
authors.affiliation: Unité d'Epidémiologie Clinique, AP-HP, Hôpital Robert Debré, Paris, France.|Inserm, U1123, ECEVE and CIC-EC 1426, Paris, France.|Univ Denis Diderot Paris 7, Sorbonne Paris Cité, Paris, France.
authors.forename: Corinne
authors.initials: C
authors.lastname: Alberti
authors.affiliation: Inserm, U1123, ECEVE and CIC-EC 1426, Paris, France.|Univ Denis Diderot Paris 7, Sorbonne Paris Cité, Paris, France.|Service de Pédiatrie Générale, AP-HP, Hôpital Robert Debré, Paris, France.
authors.forename: Mathie
authors.initials: M
authors.lastname: Lorrot
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001170:Arthritis, Infectious / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology; D001171:Arthritis, Juvenile / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology; D001707:Biopsy, Needle; D002097:C-Reactive Protein / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006760:Hospitalization; D006801:Humans; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D013582:Synovial Fluid / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D002097:C-Reactive Protein
keywords: Arthritis, Infectious; Arthritis, Juvenile; Child; Diagnosis, differential