Article Text

PDF
JUVENILE IDIOPATHIC ARTHRITIS
  1. Liza J McCann1,
  2. Lucy R Wedderburn2,
  3. Nathan Hasson2
  1. 1Royal Liverpool Children’s Hospital, Liverpool, UK
  2. 2Rheumatology Unit, Institute of Child Health, UCL and Great Ormond Street Hospital NHS Trust, London, UK
  1. For correspondence:
    Dr Liza J McCann
    Royal Liverpool Children’s Hospital, Eaton Road, Liverpool, L12 2AP, UK; Liza.McCann{at}rlc.nhs.uk

Statistics from Altmetric.com

Long-term studies have shown that juvenile idiopathic arthritis (JIA) is not as benign as previously thought, with approximately 50% of adults suffering from persistent inflammation and disability.1 Patients with erosions and disability tended to have received treatment later.2 Trials in rheumatoid arthritis suggest a 1–2 year therapeutic window to limit joint damage, with optimal control of disease achieved with the use of disease modifying drugs during the first three months of onset.3 Within paediatrics, there has been a shift towards early aggressive treatment of JIA to limit inflammation and achieve a normal lifestyle, particularly in those with poor prognostic indicators (table 1).4–6

View this table:
Table 1

 Poor prognostic indicators in juvenile idiopathic arthritis (JIA)4–6

DIAGNOSIS AND CLASSIFICATION OF JUVENILE IDIOPATHIC ARTHRITIS

JIA is defined as arthritis of unknown aetiology beginning before the 16th birthday and persisting for at least six weeks where other known conditions are excluded. The International League of Associations for Rheumatology (ILAR) classification of JIA was revised in 2001 and recently published.7 The aim of the ILAR classification is to define for research purposes mutually exclusive categories of idiopathic arthritis based on predominant clinical and laboratory features. Each category has a list of possible exclusions (table 2).

View this table:
Table 2

 International League of Associations for Rheumatology (ILAR) classification of JIA7

EPIDEMIOLOGY AND AETIOLOGY

JIA has a UK incidence of 1 in 10 000 children and a prevalence of 1 in 1000, with a female predominance.8 Although described in all races and geographic areas, large regional variations in epidemiology exist with different distributions of patients among subsets of JIA, probably due to differences in human leucocyte antigen (HLA) alleles and environment.9

DIFFERENTIAL DIAGNOSIS

Septic arthritis and osteomyelitis

Septic arthritis needs to be considered early as delayed diagnosis and treatment are associated with poor outcomes.10 It usually affects a single joint, most commonly the knee, hip, or ankle, although more …

View Full Text

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.