6.4. Rheumatology - Juvenile Idiopathic Arthritis Flashcards
What is Juvenile Idiopathic Arthritis?
A group of systemic inflammatory disorders affecting children below the age of 16 years
What is the most common Rheumatic Disease in Children?
Juvenile Idiopathic Arthritis
Note - This is an important cause of disability and blindness
What type of disease is Juvenile Idiopathic Arthritis?
Autoimmune
What is the Aetiopathogenesis of Juvenile Idiopathic Arthritis?
Multifactorial: 1. Genetic 2. Environmental 3. Immunological Note - This is different from Adult Rheumatoid Arthritis
What is the pathology of Juvenile Idiopathic Arthritis?
Environmental Factors act on Strong Subset-Specific Genetic Markers, which may affect the Immune Response
What is the Criteria for Diagnosis of Juvenile Idiopathic Arthritis?
- Age of Onset (<16 years old)
- Duration of the Disease (>6 weeks)
- Presence of Arthritis
In the Criteria for Diagnosis of Juvenile Idiopathic Arthritis, what confirms the presence of Arthritis?
Joint Swelling Or 2 of the following: 1. Painful or Limited Joint Motion 2. Tenderness 3. Warmth
How many Clinical Subtypes of Juvenile Idiopathic Arthritis are there?
3
What are the 3 Clinical Subtypes of Juvenile Idiopathic Arthritis?
- Pauciarticular (55%)
- Polyarticular (25%)
- Systemic Onset (20%)
What can the Clinical Subtype of Juvenile Idiopathic Arthritis help us suspect?
- The Natural History
- Complications
- Prognosis
- Decide the Strategy of Treatment
What does Pauciarticular Juvenile Idiopathic Arthritis involve?
Rheumatoid Arthritis of 4 or less Joints
How many Types of Pauciarticular Juvenile Idiopathic Arthritis are there?
3:
- Type 1 Pauciarticular Juvenile Idiopathic Arthritis
- Type 2 Pauciarticular Juvenile Idiopathic Arthritis
- Type 3 Pauciarticular Juvenile Idiopathic Arthritis
What is the percentage breakdown of each of the Main Types of Pauciarticular Juvenile Idiopathic Arthritis?
- Type 1 - 25%
- Type 2 - 15%
- Type 3 - 15%
How does Type 1 Pauciarticular Juvenile Idiopathic Arthritis commonly present?
- With a limp rather than pain
- No other Constitutional Manifestations
- Chronic Uveitis in 20% of cases
- Asymptomatic in 50% of cases
- Irregular Iris due to Posterior Synechiae
Which Joints are most commonly affected in Type 1 Pauciarticular Juvenile Idiopathic Arthritis?
Mainly Lower Limb Joints (most common down):
- Knee
- Ankle
- Hand (Rare)
- Elbow (Rare)
- Hip (Very Rare)
Who commonly gets Type 1 Pauciarticular Juvenile Idiopathic Arthritis?
- Girls (8:1)
2. Younger than 5 years old
Who commonly gets Type 2 Pauciarticular Juvenile Idiopathic Arthritis?
- Boys (7:1)
2. Ages after 8 / 9
What condition is seen in 10-20% of Type 2 Pauciarticular Juvenile Idiopathic Arthritis patients?
Acute Iridocyclitis (Inflammation of the Iris)
How does Type 2 Pauciarticular Juvenile Idiopathic Arthritis commonly present?
- Limp due to Lower Limb affection
2. Consitutional Symptoms are Rare
Which Joints are most commonly affected in Type 2 Pauciarticular Juvenile Idiopathic Arthritis?
Mainly Lower Limb:
- Knee
- Ankle
- Hip
How are those with HLA-B27 Positive Back Involvement categorised as?
Juvenile Ankylosing Spondylitis
How does Type 3 Pauciarticular Juvenile Idiopathic Arthritis present?
- Asymmetric Upper Limb and Lower Limb Arthritis
- Dactylitis (Inflammation of the Toes / Fingers)
- Constitutional Symptoms are Rare
Who commonly gets Type 3 Pauciarticular Juvenile Idiopathic Arthritis?
- Girls (4:1)
2. This develops at Any Age (Before 16)
What conditions are associated with Type 3 Pauciarticular Juvenile Idiopathic Arthritis?
- Chronic Iridocyclitis in 10-20% of patients (Inflammation of the Iris)
- Psoriasis (Later in life)
Note - this condition is more likely with a Family History of Psoriasis
What percentage of Pauciarticular Juvenile Idiopathic Arthritis go on to develop Polyarticular Juvenile Idiopathic Arthritis?
30%
How many Joints are involved in Polyarticular Juvenile Idiopathic Arthritis?
5 or more
What are the 2 Sub-types of Polyarticular Juvenile Idiopathic Arthritis?
- Rheumatoid Factor Positive Polyarticular Juvenile Idiopathic Arthritis
- Rheumatoid Factor Negative Polyarticular Juvenile Idiopathic Arthritis
How does Rheumatoid Factor Positive Polyarticular Juvenile Idiopathic Arthritis present?
- Symmetric Large and Small Joints affection (Knee, Wrist, Ankle, MCP, PIP, Neck)
- Consitutional Manifestations (Fever, Malaise…)
- Hepato-Splenomegaly
- Mild Anaemia
- Growth Abnormalities
- Iridocyclitis (Inflammation of the Iris) (Rare)
Who commonly gets Rheumatoid Factor Positive Polyarticular Juvenile Idiopathic Arthritis?
- Girls (9:1)
- This can present at any age (below 16)
Note - This accounts for 15% of all Juvenile Idiopathic Arthritis
How does Rheumatoid Factor Negative Polyarticular Juvenile Idiopathic Arthritis present?
Similar to Adult Rheumatoid Arthritis:
- Constitutional Manifestations (Fever, Malaise…)
- Anaemia
- Nodules
- Iridocyclitis (Inflammation of the Iris) (Rare)
- Erosions in X-Ray occur early
Who commonly gets Rheumatoid Factor Negative Polyarticular Juvenile Idiopathic Arthritis?
- Girls (7:1)
- In late Childhood (12-16 years)
Note - This accounts for 10% of all Juvenile Idiopathic Arthritis
What is the most Serious type of Juvenile Idiopathic Arthritis?
Systemic Onset of Juvenile Idiopathic Arthritis
Note - This has short and long term morbidity and mortality
Who commonly gets Systemic Onset of Juvenile Idiopathic Arthritis?
- Girls (3:2)
2. At any age throughout childhood but mainly at 4-6 years olf
What Joints does Systemic Onset of Juvenile Idiopathic Arthritis commonly affect?
- Wrists
- Knees
- Ankles
- Cervical Spine
- Hips
- TMJ
How does Systemic Onset of Juvenile Idiopathic Arthritis present?
- Arthritis
- Fever (within 3-12 months of onset)
- Salmon Red Eruption on the Trunk / Thighs
- Polyseositis (Pleural Effusion / Pulmonary Fibrosis / Pericarditis)
- Lymphadenopathy
- Abdominal Pain (+/- Transaminases)
What is the Therapy for Juvenile Idiopathic Arthritis?
- Simple Pain Killers (NSAID’s)
- Joint (Steroid) Injections
- Methotrexate
- Biologics (Anti-TNF, IL-1 Antagonist, IL-6 Antagonist)
- Local / Systemic Steroids
- Rehabilitation / Occupational Therapy
- Surgical (Synovectomy / Reconstructive)