Juvenile idiopathic arthritis

Question 1

Define juvenile idiopathic arthritis

Answer 1

Umbrella term for arthiritis in under 16yrs within unknown aetiology.
Diagnosis of exclusion -> persistent joint swelling for more than 6weeks.

Question 2

What is the key epidemiology of juvenile idiopathic arthritis?

Answer 2

Approximately 1 in every 1,000 children
Most common paeds chronic joint pain
More common in girls
More common in pre-school age or teenagers

Question 3

What is the relevant aetiology of JIA?

Answer 3

Unknown
Genetic susceptibility and environmental triggers -> immune dysregulation and inflammation in joints/tissues

Question 4

How can JIA be classified by the number of joints affected?

Answer 4

Oligoarthritis - four or fewer joints -> most common -> associated with chronic anterior uveitis
Polyarthritis - 5 or more joints - fingers, toes, wrists etc

Question 5

What is meant by enthesis-related JIA?

Answer 5

Entheses -> where tendon attach to bone
More common in legs or spine
Boys
Associated with IBD and ankylosing spondylitis

Question 6

What is psoriatic arthritis?

Answer 6

Similar to adult
Psoriasis with one or more affected joints

Question 7

What are the features of systemic onset JIA?

Answer 7

Fevers
Generalised malaise
Salmon pink rash
Lymphadenopathy
Hepatosplenomegaly
Pericarditis
Alongside joint presentation

Question 8

What are the key signs and symptoms of JIA?

Answer 8

6 weeks or more:
Joint pain
Joint swelling
Morning stiffness
Limited range of motion

Question 9

What joint is more commonly affected in juvenile arthritis compared to adults?

Answer 9

The temporomandibular joint

Question 10

What symptoms are less common but should be aware of in juvenile idiopathic arthritis?

Answer 10

Pyrexia
Rash
Uveitis - pain and redness -> can lead to vision loss
Serositis - affecting lungs and heart

Question 11

What are the key investigations of JIA?

Answer 11

Note is primarly clinical - of exclusion
Bloods - FBC, ESR, CRP, ANA, RF, HLA-B27
Imaging - US or MRI -> synovial hypertrophy, effusion or bone erosion
Joint aspiration

Question 12

What is the hollistic management of JIA?

Answer 12

MDT
Emotional and psychological support
Physio and OT
Opthalmology review -> regular eye checks for vision loss
Paeds

Question 13

What are the medical management stratergies for juvenile idiopathic arthritis?

Answer 13

NSAIDs -> symptoms control
Steroids -> oral or intra-articular
Steroid sparing - methotrexate, TNF-alpha inhibitors (abatecept)

Question 14

What are some potential complications of juvenile idiopathic arthritis?

Answer 14

Flexion contractures - splinting and physio
Joint destruction - necessiate protheses at young age
Growth failure -> due to chronic disease and steroid use
Anterior uveitis -> vision loss
Macrophage activation syndrome - fever, hepatosplenomegaly, encephalopathy, raised LFTs and high ferriting
Osteoporosis

Question 15

What is the typical prognosis of juvenile idiopathic arthritis?

Answer 15

Majority of JIA positive have chronic disease
50% of oligoarticular JIA have long term joint problems
RF positive have poor prognosis