Juvenile idiopathic arthritis: the AU general practice approach

What juvenile idiopathic arthritis is

Juvenile idiopathic arthritis (JIA) is the umbrella term for chronic inflammatory joint disease beginning before age 16 and persisting for ≥6 weeks, after excluding identifiable causes. It is the most common chronic autoimmune musculoskeletal condition in children in Australia, with a prevalence of approximately 1 in 1,000 children.

JIA is not a single disease. The International League of Associations for Rheumatology (ILAR) classification identifies seven subtypes with distinct genetics, clinical courses, and prognoses. The most important for general practice to recognise are oligoarticular JIA (the most common), polyarticular JIA (RF-negative and RF-positive), systemic JIA (with systemic features including quotidian fever and rash), and psoriatic JIA.

The clinical imperative in general practice is twofold: early recognition and prompt referral to avoid diagnostic delay, and long-term shared care surveillance once the diagnosis is established. The most dangerous complication — asymptomatic anterior uveitis — is a GP responsibility to monitor.

A. Core clinical — the AU general-practice framework

Subtypes and their clinical behaviour

Subtype	Joint pattern	Key features	GP priority
Oligoarticular (≤4 joints, first 6 months)	Usually large joints (knee, ankle)	ANA positive; uveitis risk	Refer; arrange ophthalmology
Polyarticular RF-negative	≥5 joints	Variable severity; ANA variable	Refer; methotrexate often needed
Polyarticular RF-positive	≥5 joints, small hand/wrist	Behaves like adult RA	Urgent referral; early DMARD
Systemic JIA	Variable	Quotidian fever, salmon rash, serositis	Urgent; can be life-threatening
Psoriatic JIA	Mixed	Skin psoriasis, dactylitis, nail changes	Refer; biologics often needed
Enthesitis-related	Axial + large joints	HLA-B27 associated; adolescent boys	Refer; NSAIDs + sulfasalazine
Undifferentiated	Doesn’t fit other categories	—	Refer

History to take

The Royal Children’s Hospital Melbourne clinical guidelines and eTG recommend focused assessment:

• Joint symptoms — swelling, warmth, stiffness, pain; morning stiffness duration (>30 min suggests inflammation); functional limitation (difficulty stairs, opening jars, writing)
• Duration — ≥6 weeks required; ask about past episodes
• Systemic features — fever pattern (quotidian fever: daily spike to ≥39 °C returning to normal, classic for systemic JIA), rash, weight loss, fatigue, lymphadenopathy
• Growth — height and weight centiles; chronic inflammation impairs growth
• Eye symptoms — red eye, blurred vision; but emphasise that JIA uveitis is usually asymptomatic
• Family history — psoriasis, IBD, ankylosing spondylitis (enthesitis-related), autoimmune disease
• Medications — prior NSAIDs and response; corticosteroids

Examination

• Joints — swelling (synovial thickening vs effusion), warmth, range of motion, tenderness; do NOT rely on tenderness alone; synovial swelling is objective
• Gait — antalgic gait, leg-length discrepancy (overgrowth adjacent to inflamed knee is common)
• Eyes — assess for anterior uveitis (slit-lamp, not torch exam); red eye, irregular pupil, posterior synechiae visible only on slit-lamp
• Skin — psoriatic plaques, nail pits/onycholysis; evanescent salmon-pink rash of systemic JIA appears with fever spike
• Lymph nodes, spleen, liver — systemic JIA can cause significant organomegaly
• Growth parameters — plot on centile charts

Investigations

• FBC, ESR, CRP — elevated in active JIA but can be normal (especially oligoarticular); normal inflammatory markers do not exclude JIA
• ANA — positive in ~70% of oligoarticular JIA; flags high uveitis risk; not diagnostic but guides ophthalmology frequency
• RF (IgM) — positive in RF-positive polyarticular subtype; associated with worse prognosis
• Anti-CCP — more specific than RF for erosive disease in adolescents
• HLA-B27 — enthesitis-related JIA; ordered selectively
• Ferritin — markedly elevated (often >500 µg/L, sometimes >10,000) in systemic JIA and macrophage activation syndrome
• Musculoskeletal ultrasound — GP-accessible; detects synovitis and effusion; useful when clinical signs subtle
• Plain X-rays — early disease usually normal; periosteal reaction, erosions, joint space narrowing are late changes

B. Evidence — treatment hierarchy in Australian practice

NSAIDs as initial treatment

eTG and AMH recommend NSAIDs for initial symptom management: naproxen 10–20 mg/kg/day in two divided doses or ibuprofen 30–40 mg/kg/day. NSAIDs reduce pain and stiffness but do not modify disease progression. They are appropriate while awaiting specialist review and for mild oligoarticular disease.

Intra-articular corticosteroids

Intra-articular triamcinolone hexacetonide is first-line joint-specific treatment in oligoarticular JIA, administered under ultrasound guidance. It provides sustained remission of individual joints and is preferred over systemic corticosteroids. Oral or IV systemic corticosteroids are reserved for systemic JIA with life-threatening features (macrophage activation syndrome, serositis) or as a bridge before DMARD effect.

Methotrexate

Methotrexate 10–15 mg/m²/week (oral or subcutaneous) is the cornerstone systemic DMARD for polyarticular JIA in Australia, PBS-listed for specialist-initiated use. Efficacy is well-established across multiple RCTs. Subcutaneous route improves bioavailability and GI tolerability. Monitoring: FBC and LFTs at baseline, 4 weeks, then 3-monthly when stable. Folic acid 5 mg weekly (not on methotrexate day) reduces adverse effects.

Biologics

For children inadequately controlled on methotrexate, PBS-listed biologics (under the Rheumatoid Arthritis section with paediatric extensions) include:

• Etanercept — TNF inhibitor; most established evidence in polyarticular JIA; approved ≥2 years
• Adalimumab — TNF inhibitor; preferred for uveitis (both active and prophylactic); approved ≥2 years
• Tocilizumab — IL-6 receptor inhibitor; PBS-listed specifically for systemic JIA; IV or subcutaneous
• Abatacept — CTLA4-Ig; option for RF-positive disease; subcutaneous

Biologic therapy is initiated and managed by the paediatric rheumatologist; GPs co-manage routine monitoring and infections.

C. Uveitis — the silent complication that blinds

Anterior uveitis affects 10–25% of oligoarticular JIA and is the most common extra-articular complication. It is asymptomatic and undetectable without slit-lamp examination — waiting for a red eye means damage has already occurred.

Australian Rheumatology Association surveillance guidelines based on uveitis risk:

Risk	Criteria	Ophthalmology frequency
High	Oligoarticular or psoriatic JIA + ANA positive + age under 7 years at onset + disease duration under 4 years	Every 3 months
Medium	Oligoarticular or psoriatic JIA + ANA positive OR age 7–11 at onset	Every 4–6 months
Low	RF-positive polyarticular, systemic JIA, enthesitis-related + older age	Annually

GP role: confirm that ophthalmology surveillance is active at every review. If a child with JIA has not had a slit-lamp exam in the recommended timeframe, re-refer urgently. Adalimumab has evidence for prevention and treatment of JIA-associated uveitis resistant to topical corticosteroids.

D. Australian operations

PBS access

Methotrexate, etanercept, adalimumab, tocilizumab, and abatacept are PBS Section 85 or Section 100 items for paediatric JIA, initiated by paediatric rheumatologists. GPs can write continuing prescriptions under specialist direction. The specialist letter should specify the biologic, dose, frequency, and monitoring requirements.

Shared care model

The typical Australian JIA shared-care arrangement involves:

• Paediatric rheumatologist — diagnosis, initiation and adjustment of DMARD/biologic therapy, disease monitoring, uveitis coordination
• GP — routine monitoring bloods, infection management, intercurrent illness, vaccination coordination, psychosocial support
• Ophthalmologist — slit-lamp uveitis surveillance per risk-stratified schedule
• Physiotherapist and occupational therapist — joint protection, splinting, exercise programme
• Paediatric nurse specialist — biologic injection training, patient education

Most Australian paediatric rheumatology services are in tertiary children’s hospitals (RCH Melbourne, Sydney Children’s Network, Queensland Children’s Hospital, Perth Children’s Hospital, Women’s and Children’s Adelaide). Telehealth options have expanded rural access.

Intercurrent illness and biologic hold

Children on TNF inhibitors or other biologics should withhold the biologic dose during significant febrile illness. GPs must know to hold the injection for fever, bacterial infection, or surgical procedures and notify the rheumatologist. Routine childhood viral illnesses generally do not require a hold.

E. Special populations

Systemic JIA and macrophage activation syndrome (MAS). Systemic JIA with features of MAS (dramatically elevated ferritin >10,000 µg/L, pancytopenia, rising transaminases, coagulopathy, CNS features) is a medical emergency — admit immediately. Tocilizumab and anakinra are used in specialist centres.

Adolescents transitioning to adult care. Transition to adult rheumatology services (typically 16–18 years in Australia) requires planned handover. RF-positive polyarticular JIA transitions to adult rheumatoid arthritis services. GPs play a key role bridging this gap and supporting adolescent self-management and medication adherence. Contraception and bone health need addressing before transition.

Bone health. Chronic inflammation and corticosteroid use both impair bone density. Weight-bearing exercise, adequate calcium and vitamin D, and DEXA scanning are appropriate for children with prolonged active disease or corticosteroid exposure. Arthritis Australia provides patient-facing exercise and bone health resources.

Mental health. Chronic pain, school disruption, social limitations, and visible joint swelling carry significant psychological burden. Anxiety and depression are more prevalent in children with JIA than peers. Psychological support through the paediatric team (psychologist, social worker) and GP mental health care planning is important.

Growth impairment. Chronic systemic inflammation and corticosteroid use impair linear growth. Regular height/weight centile plotting by the GP allows early identification; refer to paediatric endocrinology if significant growth failure occurs.

When to escalate

Escalate (urgent paediatric rheumatology or emergency) when:

• Any child with objectively swollen joints persisting ≥6 weeks — refer paediatric rheumatology
• Systemic JIA with high spiking fevers + rash + serositis — urgent
• Suspicion of macrophage activation syndrome (ferritin >10,000, pancytopenia) — emergency admission
• Uveitis detected on slit-lamp — urgent rheumatology ± ophthalmology escalation
• Biologic-related serious infection (bacterial, fungal, TB reactivation) — emergency
• Anterior uveitis uveitis progressing despite topical therapy — add adalimumab, via rheumatologist

What this article is and is not

This is general health information drawn from current Australian general practice and paediatric rheumatology guidelines — eTG, AMH, Royal Children’s Hospital Melbourne, Australian Rheumatology Association, Arthritis Australia, RACGP, and PBS. It is not personal medical advice and does not create a doctor–patient relationship. Decisions about diagnosis and treatment of joint disease in children are made with the child’s GP and paediatric rheumatology team.

For Australian consumer resources: Arthritis Australia — JIA, HealthDirect — JIA, RCH Patient Education.

For acute joint emergencies or suspected MAS: present to the nearest paediatric emergency department.

---

Sources cited

1. Australian Rheumatology Association
2. Therapeutic Guidelines (eTG) — Paediatric rheumatology
3. Australian Medicines Handbook — Children’s Dosing Companion
4. Royal Children’s Hospital Melbourne — JIA guidelines
5. Arthritis Australia
6. RACGP
7. PBS — paediatric biologics
8. Australian Immunisation Handbook — ATAGI immunocompromised
9. HealthDirect — JIA
10. Ravelli A, Martini A — JIA review (Lancet 2007)
11. Petty RE et al — ILAR classification criteria (J Rheumatol 2004)