About JIA

About Juvenile Arthritis

Juvenile arthritis is a painful, inflammatory, autoimmune disease of unknown aetiology diagnosed before the age of 16. Its correct name is juvenile idiopathic arthritis (JIA).

Prevalence

JIA is one of the commonest chronic childhood diseases and the most common childhood rheumatic disease. The prevalence of JIA is between 1 and 4 cases per 1,000 children. There are an estimated 6-10,000 children aged 0 -16 with juvenile arthritis and up to 30,000 young Australian aged 0-24. This is similar to diabetes in the same age group.¹

Disease classification

JIA is classified as a childhood rheumatic disease (CRD) and accounts for around 80% of all CRDs. The remaining 20% comprise less common conditions such as systemic lupus erythematosus (SLE), chronic relapsing multifocal osteomyelitis (CRMO) and juvenile dermatomyositis (JDM).

JIA is a collective term for seven subtypes of childhood arthritis that affect the joints, eyes and, in some cases, the skin, muscles and internal organs (see Appendix 1).²

Signs and symptoms

Symptoms of JIA usually include one or more stiff, swollen, painful, joints and in some cases can include a rash and/or fever. There may also be eye signs and symptoms. There is no definitive blood test for JIA. A thorough history, particularly morning stiffness and unexplained symptoms for 6 weeks or more, and physical examination is central to making a diagnosis. Blood tests, x- rays or scans may be required to exclude other possible causes such as infection or malignancy.

Diagnosing JIA

Uveitis

Up to 20% of children with arthritis will have uveitis – a serious inflammatory, vision threatening eye disease that is the commonest cause of childhood blindness in developed countries. It is important to note that:

  1. Uveitis is often asymptomatic
  2. Screening for uveitis in children with juvenile arthritis is critical
  3. Uveitis can develop even when the arthritis is inactive
  4. Most patients need systemic therapy for successful long-term control of uveitis

All children with JIA need regular eye examinations.

Sequelae

Over 80% of children with JIA experience daily pain. Many suffer unpredictable acute ‘flares’ of their arthritis which, if severe, may require hospitalisation. Although biologics have revolutionised the treatment and outcomes of JIA, many children and young people with JIA still suffer a high burden of:

  • Permanent disability, most notably from joint damage
  • Visual impairment, cataracts, glaucoma, and even blindness
  • Time off school / lost educational opportunity
  • Mental ill health ranging from anxiety and depression to suicidal ideation.

In around 70% of affected children, JIA continues into adulthood, accounting for tens of thousands of young adults with moderate to severe disability and /or requiring joint replacements or reconstructive surgery.

Overall Management

All forms of JIA require ongoing care and clinical monitoring by multidisciplinary teams of specialist paediatric rheumatology doctors, nurses, physiotherapists, occupational therapists, podiatrists, psychologists, dieticians, and uveitis specialists. Ongoing clinical monitoring and access to specialist multi-disciplinary teams, self-care education and behavioural and psychosocial support, are essential for optimal outcomes.

Medical treatment

The medical treatment of JIA is highly complex. It aims to drive the inflammatory process into remission as early as possible while preserving normal growth and development and minimising side effects. In addition to simple anti-inflammatories, treatment involves use of powerful immunomodulating medications including methotrexate, biologics and steroids. Many children also require frequent joint aspiration and/or corticosteroid injections under general anaesthetic.

TypeExamplePurpose
Pain Medication (analgesics)ParacetamolHelps to control mild to moderate pain, and reduce fever. Does not reduce inflammation.
Non-steroidal anti-inflammatory drugs (NSAIDs)Naproxen
Ibuprofen
Celebrex
Piroxicam
Reduces pain, stiffness and inflammation.
Steroids (corticosteroids)PrednisoloneReduces inflammation and eases pain. They usually work quickly and are short- term treatments. May be injected into the affected joint, given orally or by infusion.
Disease-modifying anti-rheumatic drugs (DMARDs)Methotrexate
Sulfasalazine
Hydroxycholoriquine
Leflunomide
Reduces the immune system which is overactive. They take time to work (weeks or months) and control the disease over the long-term.
bDMARDS (Biologics)
Etanercept
Adalimumab
Tocilizumab
Abatacept
Rituximab
Tofacitinib
Secukinumab
These target specific chemicals or cells in the immune system. Sometimes given alongside DMARDs.

GPs can play an important role in supporting families by providing routine care and advice and co-ordinating services for young patients with JIA.

APPENDIX 1 – Subtypes of JIA

There are seven subtypes of JIA²:

  • Oligoarticular – affects four or less joints. This is the most common subtype.
  • Polyarticular (RhF negative) – when five or more joints are affected. Rheumatoid factor (RhF) antibody is not found on blood testing.
  • Polyarticular (RhF positive) – when five or more joints are affected and RhF is found on blood testing. This subtype may behave similarly to rheumatoid arthritis in adults.
  • Systemic – a chronic arthritis associated with systemic features, including high spiking fever, transient episodic erythematous rash, lymphadenopathy and hepatosplenomegaly (systemic features often precede the arthritis).
  • Enthesitis related – (previously known as juvenile spondyloarthropathy). This is a chronic arthritis associated with enthesitis (inflammation at insertion of tendons, ligaments or fascia to bone), or with lower axial skeletal involvement. HLA B27 is often present or there is a family history of a first degree relative with a HLA B27 related disease. A significant proportion of patients will develop sacroiliitis as adults, but back and sacroiliac joint involvement is less common during childhood.
  • Psoriatic – chronic arthritis, usually with asymmetrical involvement of small and large joints, and either the development of psoriasis or other evidence of a psoriatic diathesis (two of the following: family history in a first degree relative, nail pits or onycholysis, or dactylitis).
  • Undifferentiated arthritis – arthritis that meets more than one of the above subtypes.

References

  1. AIHW 2023 htps://www.aihw.gov.au/reports/chronic-musculoskeletal-conditions/juvenile- arthritis
  2. Petty R, Southwood T, Manners P, et al. International League of Associations for Rheumatology classification of juvenile idiopathic arthritis. 2nd revision. J Rheumatol 2004;31(2):390–2.

Quick Facts & Figures

6,000-10,000

The estimated number of Australian children living with JIA is 6,000 -10,000 making it one of the most common chronic childhood diseases.

85%

of children with JIA experience pain on a daily basis, which means lost educational opportunities and limited participation in physical and social activities.

Up to 1 in 5 Children with JIA develop a serious inflammation of the eyes (uveitis). This is a serious threat to vision and can cause permanent vision loss and possible blindness.

30,000

People in Australia whose arthritis started as JIA and extended into adulthood will have active disease as adults, and 1 in 3 of these people will have a severe disability.