Juvenile Idiopathic Arthritis

Introduction[edit | edit source]

Figure.1 Swollen Right Knee in Patient with JIA

Juvenile idiopathic arthritis (JIA) reflects a group of clinically heterogeneous, autoimmune disorders in children and teens under the age of 16, characterized by chronic arthritis and hallmarked by elevated levels of circulating immune complexes (CICs) and associated complement activation by-products in their sera.[1]

JIA can appear in many different ways and can range in severity. It mostly affects the joints and the surrounding tissues, although it can affect other organs like the eyes.

Symptoms of JIA include joint pain, swelling and stiffness.[2]

Etiology[edit | edit source]

The cause and trigger of chronic arthritis in JIA remain unclear.

  1. Abnormal immune responses triggered by the interactions between environmental factors in a genetically susceptible individual is speculative.
  2. JIA is not hereditary – it is not passed on from parent to child. It is rare for two children in the same family to have JIA, although this can happen[3].
  3. Some environmental factors such as antibiotic exposure and C-section deliveries are potential risks; however, breastfeeding and household siblings are possible protectives.[4]

Epidemiology[edit | edit source]

JIA is the most common rheumatic disease reported in children of the Western world. The incidence and prevalence are varied among 1.6 to 23 new cases for 100000 children[4].

  • JIA affects 30,000 to 50,000 children in the United States.[5]
  • JIA affects at least one child in every 1,000 in Australia[3]. For unknown reasons, it has been shown to be more prevalent in Norway and Australia.[6]
  • Effects more than twice as many girls as their male counterparts.
  • The mean age of onset is 1-3 years old.[6]

Characteristics and Clinical Presentation[edit | edit source]

Figure.3 Uveitis

The symptoms the child experiences will depend on the type of arthritis they have. Common symptoms include:

  • pain, swelling and stiffness in one or more joints
  • skin over the affected joints may be warm or red
  • mental and physical tiredness, or fatigue.

Less common symptoms include:

  • fever
  • rash
  • feeling generally unwell
  • eye inflammation (uveitis)[2]

Diagnostic Tests[edit | edit source]

JIA is diagnoses according to patient and family medical history, symptoms, number of joints involved, lab tests and sometimes imaging.

Juvenile idiopathic arthritis is diagnosed using a number of tests including:

  • medical history
  • physical examination
  • blood tests – however, most children diagnosed with juvenile idiopathic arthritis do not have rheumatoid factor in their blood, so blood tests do not eliminate juvenile idiopathic arthritis
  • x-rays and scans
  • eye examination.[2]

Pathology[edit | edit source]

Figure.2 Prevalence of Major Subtypes of JIA[7]

There are several subtypes of JIA:

  1. Oligoarticular JIA (Pauciarticular)
    • affected ≤4 joints in the first six months of illness
    • peak age: 1-6 years
    • mainly affects medium and large joints
  2. Polyarticular JIA (pJIA)
    • ≥5 joints are affected
    • peak age: 1-4 years; 7-10 years
    • mainly affects small and medium joints
  3. Systemic onset JIA (Still's disease, not to be confused with adult onset Still's disease)
    • arthritis may present weeks to months after the onset of systemic symptoms[8]
  4. Enthesitis-related JIA
  5. Psoriatic JIA
  6. Undifferentiated JIA[2]

Management and Interventions[edit | edit source]

Treatment of JIA requires anti-inflammatory and immuno-modulatory drugs and physical therapy, and eventually, surgery, nutritional support, and psychosocial support may be needed.

The choice of pharmacological treatment depends on the disease subtypes, disease severity and damage, associated disease, and family acceptance. Non-steroidal anti-inflammatory drugs (NSAIDs) are the mainstay of initial symptomatic treatment for all subtypes. The NSAID use in JIA has decreased over time with modern aggressive treatment, including methotrexate and biologics.[4]

The main treatments for arthritis include:

  • medications to control the inflammation (including tablets, injections, infusions, eye drops)
  • exercises to keep the joints moving well and the muscles strong
  • splints to support the joints
  • joint injections to reduce inflammation in particular joints
  • pain management strategies to reduce pain and to help your child cope with pain[3]

Pharmacology Management[edit | edit source]

The doctor will always start with the simplest medications at the smallest doses and work their way up to more complex medications and larger doses depending on how the child’s condition responds to the treatments.

The most common types of medications used for JIA are:

  • pain-relievers (analgesics) – for temporary pain relief
  • creams and ointments – can be rubbed into the skin over a painful joint to provide temporary pain relief
  • eye drops – to treat eye inflammation
  • non-steroidal anti-inflammatory drugs (NSAIDs) – to control inflammation and provide pain relief
  • corticosteroids – used to quickly control or reduce inflammation. They can be taken as tablets or given by injection directly into a joint, muscle or other soft tissue
  • disease modifying anti-rheumatic medications (DMARDs) – work on controlling the immune system. These medications help relieve pain and inflammation, and can also reduce or prevent joint damage
  • biologics and biosimilar medicines (bDMARDs) – are also a type of disease modifying drug. They also work on controlling the immune system. However unlike other disease modifying drugs, biologics target specific cells and proteins that are causing the inflammation and damage, rather than suppressing the entire immune system.  

Physiotherapy Management[edit | edit source]

Physical therapy is an important part of the treatment of JIA. It is important for the child to remain active and involved in sports and activities with their peers and friends. While pain may limit the amount of activity a child can handle it is important to encourage involvement during periods or remission and allow rest and symptom reducing therapies during periods of flare-ups. Regular activity and general exercise programs help to maintain range of motion in affective joints, build and maintain strength, maintain function and can even help with symptom reduction.

Aspects that should be focused on during a physical therapy session are as follows[6]:

Some modalities that can be used to help reduce symptoms such as pain are:

Differential Diagnosis[edit | edit source]

Some signs and symptoms of JIA are shared with those of the following diseases[6][10]:

Case Reports/ Case Studies[edit | edit source]

Juvenile Idiopathic Arthritis Treatment Roundup: What’s Available and What’s Upcoming? https://www.rheumatologyadvisor.com/home/topics/pediatric-rheumatology/juvenile-idiopathic-arthritis-jia-treatment-therapy-strategies-updates-future/

Clinical Trials: Rheumatology Network https://www.rheumatologynetwork.com/clinical/juvenile-arthritis

References[edit | edit source]

  1. Moore TL. Immune complexes in juvenile idiopathic arthritis. Frontiers in immunology. 2016 May 20;7:177.Available:https://www.frontiersin.org/articles/10.3389/fimmu.2016.00177/full (accessed 18.10.2021)
  2. 2.0 2.1 2.2 2.3 better Health Juvenile Arthritis Available: https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/arthritis-juvenile(accessed 18.10.2021)
  3. 3.0 3.1 3.2 Arthritis org. JIA Available:https://www.arthritisact.org.au/juvenile-arthritis/ (accessed 18.10.2021)
  4. 4.0 4.1 4.2 Thatayatikom A, De Leucio A. Juvenile Idiopathic Arthritis. StatPearls [Internet]. 2020 Aug 10. Available: https://www.ncbi.nlm.nih.gov/books/NBK554605/(accessed 18.10.2021)
  5. Goodman C, Fuller K. Pathology: Implications for the Physical Therapist. 3rd ed. . St. Louis, MO: Saunders, an imprint of Elsevier Inc, 2009.
  6. 6.0 6.1 6.2 6.3 eMedicine. Disease fact sheet: juvenile rheumatoid arthritis. http://emedicine.medscape.com/article/409980-overview (accessed 10 March 2011)
  7. Goodman C, Fuller K. Pathology: Implications for the Physical Therapist. 3rd ed. . St. Louis, MO: Saunders, an imprint of Elsevier Inc, 2009.
  8. Radiopedia JIA Available: https://radiopaedia.org/articles/juvenile-idiopathic-arthritis (accessed 18.10.2021)
  9. National Institute of Arthritis and Musculoskeletal and Skin Diseases. Health information: juvenile arthritis. http://www.niams.nih.gov/Health_Info/Juv_Arthritis/default.asp (accessed 10 March 2011)
  10. National Center for Biotechnology Information, U.S. National Library of Medicine. Disease fact sheet: http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001487/ (10 March 2011)