Paediatric Rheumatology Flashcards
Juvenile idiopathic arthritis pathophysiology
Autoimmune inflammation of the joints lasting more than 6 weeks with no identifiable cause
Presentation of JIA
- Joint pain
- Swelling
- Stiffness
Still’s disease
Systemic JIA:
- salmon pink rash
- high swinging fevers
- enlarged lymph nodes
- weight loss
- joint inflammation and pain
- splenomaegaly
- muscle pain
- pleuritis and pericarditis
Investigations for JIA
Raised inflammatory markers - CRP, ESR, platelets and serum ferritin
Antinuclear antibodies and rheumatoid factor is negative
Complications of still’s disease
Macrophage activation syndrome:
- Disseminated intravascular coagulation (DIC)
- Anaemia
- Thrombocytopenia
- Bleeding
- Non blanching rash
Polyarticular JIA
Idiopathic arthritis in > 5 joints
- symmetrical
- minimal or mild systemic features
- can be RF postive (seropositive)
Oligoarticular JIA features
Involves < 4 joints
Normally 1 joint (monoarthritis)
Normally larger joints
Associated with uveitis - refer to opthalmologist
Antinuclear antibodies often positive
Who is more likely to get oligoarticular arthritis
Girls under 6 yo
Enthesitis related arthritis
Includes:
- Ankylosing spondylitis
- psoriatic arthritis
- reactive arthritis
- IBD related arthritis
Inflammatory arthritis + enthesitis
Who commonly gets enthesitis related arthritis
Boys over the age of 6 yo
What HLA is associated with enthesitis related arthritis
HLA - B27
What is an enthesis
Point at which a muscle tendon inserts into bone
Presentation of juvenile psoriatic arthritis
Either symmetrical polyarthritis affecting small joints or asymmetrical arthritis affecting large joints in the lower limb
Henoch Schonlein purpura pathophysiology
IgA vasculitis that presents with a purpuric rash affecting the lower limbs and buttocks in children due to IgA deposits in the blood vessels. It affects the skin, kidneys and GI tract
Features of Henoch - Schonlein purpura
Purpura - non blanching, can cause skin necrosis
Joint pain - often knees and ankles
Abdominal pain
Renal involvement - IgA nephritis - haematuria
What is Henoch - Schonlein purpura triggered by?
Often triggered by a URTI or gastroenteritis
Complications of henoch - scholein purpura
GI haemorrhage
Intussuseption
Bowl infarction
How is Henoch - Schonlein purpura diagnosed
Exclude other pathology:
- FBC and blood film - thrombocytopenia, leukemia, sepsis
- U+Es
- Serum albumin - nephrotic syndrome
- CRP - sepsis
- Blood culture - sepsis
- Urine dipstick - proteinuria
- Urine protein: creatinine ratio
- Blood pressure
Use diagnostic criteria - EULAR/PRINTO/PRES
EULAR criteria
Palpable purpura + at least 1 of:
- diffuse abdo pain
- arthritis or arthralgia
- IgA deposits on histology
- proteinuria or haematuria
Management of Henoch - Schonlein purpura
Supportive - analgesia, rest and hydration
Monitor with repeated urine dipstick and BP
Who commonly gets Henoch - Schonlein purpura
Children under 10 yo
Pathophysiology of Kawasaki disease
Systemic medium sized vessel vasculitis affecting young children, typically under 5 years old.
No clear trigger
Whi is most likely to get Kawaski disease
Asian boys under 5 yo
Presentation of Kawasaki disease
Persistent high fever for more than 5 days without a clear cause
- widespread erythematous maculopapular rash
- skin peeling (desquamation) on the palms and soles
- strawberry tongue
- cracked lips
- cervical lymphadenopathy
- bilateral conjunctivitis
Investigations for Kawasaki disease
Bloods:
- FBC - anaemia, thrombocytopenia, leucocytosis
- LFTs - hypoalbuminaemia and elevated liver enzymes
- CRP and ESR
- Urinalysis
- Echocardiogram - coronary artery anuerysms
Kawasaki disease course
Acute phase - 1 - 2 weeks - most unwell with fever, rash and lymphadenopathy
Subacute phase - 2 - 4 weeks acute synotoms settle, can get desquamation and arthralgia
Convalescent stage - further 2 - 4 weeks - remaining symptoms settle, tests normalise and coronary artery aneurysms may regress
Management of Kawasaki disease
High dose aspirin
IV immunoglobulin
Monitor and follow up with echocardiogram
Complications of Kawasaki disease
Coronary artery aneurysm
Rheumatic fever pathophysiology
Autoimmune condition triggered by antibodies specific to Group A beta haemolytic - streptococcus (typically Streptococcus pyogenes) bacteria affecting the joints, heart, skin and nervous system
Type 2 hypersensitivity reaction
Presentation of rheumatic fever
Symptoms occure 2 - 4 weeks after a streptococcal infection like tonsillitis
Present with:
- Fever
- Joint pain - hot swollen painful joints
- Rash
- Shortness of breath - pericarditis, myocarditis and endocarditis - may get murmur
- Chorea - involuntary muscle movements
- Nodules
Cardiac signs due to rheumatic fever
Tachycardia or bradycardia
Murmurs
Pericardial rub
Heart failure - crackles in chest
What skin signs are seen in rheumatic fever
Subcutaneous nodules - painless, firm nodules on extensor surfaces
Erythema marginatum rash - pink rings of varies size on torso and proximal limbs
Chorea
Irregular, rapid and uncontrolled movements of limbs - sydenham chorea also known as St Vitus dance
Assessment of rheumatic fever
Throat swab - bacterial culture ASO - antistreptoccal antibody titres Echocardiogram ECG Chest Xray
Which criteria is used to daignose rheumatic fever
Jones criteria
Jones criteria
2 major or 1 major + 2 minor
Major:
- Joint involvement
- Organ inflammation - carditis
- Nodules
- Erythema marginatum
- Sydenham chorea
Minor:
- Fever
- ECG changes - prolonged PR interval with carditis
- Arthralgia
- Raised inflammatory markers
Management of rheumatic fever
Treat streptococcal infection with phenoxymethylpencillin for 10 days
Refer for specialist management
- NSAIDS - joint pain
- Aspirin if > 16 yo and steroids for carditis
Complications of rheumatic fever
Chronic heart failure
Mitral stenosis
Recurrence
