Rheumatology - Juvenile Idiopathic Arthritis

Question 1

What is JIA?

Answer 1

Autoimmune inflammation of the joints causing arthritis in children and adolescents

Question 2

How is JIA diagnosed?

Answer 2

Arthritis without any other cause lasting more than 6 weeks in under 16s

Question 3

What are the key features of JIA?

Answer 3

Joint pain
Swelling
Stiffness

Question 4

What are the 5 different subtypes of JIA?

Answer 4

• Systemic JIA
• Polyarticular JIA
• Oligoarticular JIA
• Enthesitis related arthritis
• Juvenile psoriatic arthritis

Question 5

How is systemic JIA also known?

Answer 5

Still’s disease

Question 6

What are the typical features of systemic JIA?

Answer 6

• Subtle salmon-pink rash
• High swinging fevers
• Enlarged lymph nodes
• Weight loss
• Joint inflammation and pain
• Splenomegaly
• Muscle pain
• Pleuritis and pericarditis

Question 7

What is raised in systemic JIA?

Answer 7

CRP
ESR
Platelets
Serum ferritin

Rheumatoid and ANA are negative

Question 8

What is a key complication of systemic JIA?

Answer 8

Macrophage activation syndrome

Severe activation of the immune system with a large inflammatory response

Question 9

How does macrophage activation syndrome present?

Answer 9

Presents with acutely unwell child with
- DIC
- Anaemia
- Thrombocytopenia
- Bleeding
- NBR

Life threatening

Question 10

What investigation is key in macrophage activation syndrome?

Answer 10

Low ESR

Question 11

What are the key non-infective differentials for high fevers in kids for over 5 days?

Answer 11

Kawasaki disease
Still’s disease
Rheumatic fever
Leukaemia

Question 12

What is polyarticular JIA?

Answer 12

Idiopathic inflammatory arthritis in** 5 joints or more**

Symmetrical

Can affect small joints of hands and feet and large joints e.g. hips and knees

Question 13

What symptoms are there in polyarticular JIA?

Answer 13

• Joint pain
• Joint swelling
• Joint stiffness
• Mild fever
• Anaemia
• Reduced growth

Question 14

What is the difference between seronegative and seropositive in polyarthritis?

Answer 14

Seronegative - rheumatoid factor negative

Seropositive - rheumatoid factor positive

Polyarthritis is equivalent to rheumatoid arthritis in adults

Question 15

What is oligoarticular JIA?

Answer 15

4 joints or less

Usually only affects a single joint - monoarthritis

Tends to affect larger joints e.g. knee or ankle

Occurs more in girls under 6

Question 16

What classic feature is associated with oligoarticular JIA?

Answer 16

Anterior uveitis

Oligo = Ophthalm

Question 17

What symptoms are there in oligoarticular JIA?

Answer 17

No systemic symptoms

Just joint issues

Question 18

What is elevated in OJIA?

Answer 18

Inflammatory markers are normal or slightly elevated

ANA are often positive
Rheumatoid are negative

Question 19

What is Enthesitis-Related Arthritis?

Answer 19

Common in boys over 6

Paediatric version of seronegative spondyloarthropathy conditions

Inflammatory arthritis in joints + enthesitis

Question 20

What is enthesitis?

Answer 20

Inflammation at the point tendon inserts into a bone

Question 21

What can cause enthesitis?

Answer 21

Traumatic stress by repetitive strain in sports or autoimmune inflammation

Question 22

How can enthesitis be detected?

Answer 22

MRI scan

Unable to differentiate between stress or autoimmune

Question 23

What do majority of patients with enthesitis-related arthritis have?

Answer 23

HLAB27 gene

Question 24

What should you look for when assessing a patient with enthesitis-related arthritis?

Answer 24

• Psoriasis signs
• IBD signs
• Anterior uveitis

Question 25

What should you do when examining a patient with enthesitis-related arthritis?

Answer 25

Patients will be tender to palpation of the entheses Palpate - IPJs - Wrist - Over greater trochanter on lateral hip - Quadriceps insertion at the ASIS - Quadriceps and patellar tendon at the patella - Base of the Achilles - Metatarsal heads on base of the foot

Question 26

What is juvenile psoriatic arthritis?

Answer 26

Seronegative inflammatory arthritis associated with psoriasis Can have symmetrical polyarthritis affecting small joints or asymmetrical arthritis affecting large joints

Question 27

What signs on examination are associated with juvenile psoriatic arthritis?

Answer 27

- Plaques of psoriasis - Nail pitting - Onycholysis (separation of nail from the bed) - Dactylitis (full finger inflammation) - Enthesitis

Question 28

How is JIA managed?

Answer 28

**Paediatric rheumatology with a specialist MDT** Reduce inflammation in joints and minimise symptoms - NSAIDs - Steroids, either oral, IM or intra-articular in oligoarthritis - DMARDs - Biologic therapy e.g. TNFis, infliximab