Idiopathic Juvenile Arthritis

Question 1

Define idiopathic arthritis

Answer 1

Objective arthritis (swelling in one or more joints) for at least 6 weeks manifesting <16 years old in the absence of infection or other defined cause

Question 2

Define arthritis, oligoarthritis, polyarthritis and still’s disease

Answer 2

Arthritis: swelling or effusion, increased warmth, and/or painful limited movements with or without tenderness

Oligoarthritis/Pauciarticular: 4 or less joints are effected (60% JIA cases)

Polyarthritis: >4 joints affected

Systemic: Still’s disease - fever and rash

Question 3

What are the risk factors for juvenile idiopathic arthritis

Answer 3

Female sex
Leukocyte antigen polymorphisms
FHx autoimmunity

Question 4

What are the symptoms of juvenile idiopathic arthritis

Answer 4

Joint pain: >6 weeks, worse on motion and palpation
Joint swelling: commonly at the knees
Morning stiffness - may present as reluctance to have a nappy change in the morning
Gelling (stiffness after rest)
Limp
Rash: non-pruritic, non-fixed, erythematous
Fever

Question 5

What are the symptoms and signs of systemic/late juvenile idiopathic arthritis

Answer 5

pyrexia
salmon-pink rash
Genu valgum/knock knees - Inflammation ± bone expansion (overgrowth with leg lengthening/valgus in systemic onset)
lymphadenopathy
arthritis
uveitis
anorexia and weight loss

Question 6

What are the signs of juvenile idiopathic arthritis on examination

Answer 6

Limp
Joint pain
Reduced range of motion
Joint swelling
Limb length discrepancy
Rheumatoid nodules (extensor surface of tendons)
Swan-neck deformity and hand problems

Systemic: genu valgum, salmon pink rash

Question 7

What investigations should be done for juvenile idiopathic arthritis

Answer 7

Bedside: Endocervical/first catch/urethral swab for NAAT (rule out reactive arthritis)
Bloods: FBC, ESR/CRP, ANA (+), rheumatoid factor, anti-CCP
Other: US affected joints

Question 8

What is the management for juvenile idiopathic arthritis

Answer 8

Specialist paediatric rheumatology MDT
- OT and PT (inactivity leads to deconditioning, disability and decreased bone mass)
- NSAIDs
- Corticosteroids (intra-articular, high dose for remission → switch to low dose for maintenance)
- DMARDs (1 = oral/SC methotrexate, 2 = sulfasalazine)
- Biologics e.g. TNF-a inhibitors, interleukin receptor antagonists

Question 9

What are the complications of juvenile idiopathic arthritis

Answer 9

Anterior uveitis (chronic → cataracts and glaucoma)
Fractures
Growth failure
Flexion contracture of joints → joint destruction
Constitutional problems .g. anaemia of chronic disease, delayed puberty
Osteoporosis
Amyloidosis
Bone expansion → leg lengthening, valgus deformity

Question 10

What is the prognosis for juvenile idiopathic arthritis

Answer 10

Most children can expect good disease control and quality of life
Poor disease control → significant morbidity from joint damage and visual impairment leading to anterior uveitis and fractures from osteoporosis