Juvenile Idiopathic Arthritis

Question 1

What age are sufferers of JIA?

Answer 1

Children below the age of 16 years

Question 2

How prevalent is JIA?

Answer 2

1 in 1000 children under 16

Question 3

What are the criteria for diagnosis?

Answer 3

1. Age of onset <16 years
2. Duration of disease >6 weeks
3. Presence of arthritis - joint swelling or two of the following:
   - painful or limited joint motion
   - tenderness
   - warmth

Question 4

How long before the subtype of the disease can be identified?

Answer 4

6 months

Question 5

What are the three major subtypes of JIA?

Answer 5

Pauciarticular - 55%
Polyarticular - 25%
Systemic onset - 20%

Question 6

Which type of JIA is more common in males?

Answer 6

Enthesitis-related

Question 7

What is the common onset age of pauciarticular JIA?

Answer 7

Early - peak 2-4 years

Question 8

What is the common onset age of RF -ve polyarticular JIA?

Answer 8

Biphasic - 2-4yr, 6-12yr

Question 9

What is the common age of onset of RF +ve polyarticular JIA?

Answer 9

Late - teens

Question 10

What is the common age of onset of psoriatic JIA?

Answer 10

Biphasic - 2-4yr, 9-11yr

Question 11

How many different types of pauciarticular JIA are there?

Answer 11

Three:
Type I - 25%
Type II - 15%
Type III - 15%

Question 12

What is the common age of onset of type I pauciarticular JIA?

Answer 12

Before 5 years, peak 1-3 years

Question 13

What is the male:female ratio in type I pauciarticular JIA?

Answer 13

Girls:Boys 8:1

Question 14

How does type I pauciarticular JIA present?

Answer 14

Limp rather than pain

No constitutional manifestations

Question 15

Which joints does type I pauciarticular JIA commonly affect?

Answer 15

Mainly LL joints

Knee > ankle > hand or elbow (hip very rare)

Question 16

What kind of serology results is a patient with type I pauciarticular JIA likely to have?

Answer 16

Positive ANA in 40-75%