241. Peds Rheumatology

Question 1

Difference b/w autoinflammatory and autoimmune disease

Answer 1

autoinflammatory: Innate immunity, neutrophils/macrophaces, tx by blocking cytokine cascade
autoimmune: Adaptive immunity, B/T/Treg cells, tx by blocking lymphocytes/their products

Question 2

Systemic Juvenile Idiopathic Arthritis

age/sex, dx, pathophysiology

Answer 2

any age, M=F
Dx: Polyarticular symmetric arthritis, spiking QUOTIDIAN (1-2x daily) fever for 2 weeks and one more of:
evanescent rash (salmon patches/macules with fever), hepatosplenomegaly, lymphadenopathy, serositis)
PP: IL-1,6,8 drive inflammation via abnormal cytokine expression (autoINFLAMMATORY), may lead to T cell abnormalities (auto-immune?)

Question 3

SJIA labs, complication

Answer 3

Lab: anemia, thronbocytosis, high ESR/CRP, High LFTs, Coag changes (high d-dimers, fibrinogen, PT/PTT)

Macrophage Activation Syndrome: severe hyperinflammatory state (cytokine storm) may be FATAL
Labs: DIC (low ESR, pancytopenia), high LFTs, Sky high Ferritin

Question 4

SJIA tx, prognosis

Answer 4

tx: Glucocorticoids
Biologics (anti-IL-1, anti-IL-6)
2nd line: DMARDS (MTX, leflunomide)

Prognosis: mild-severe involvement, VARIABLE course

Question 5

Kawasaki Disease

Diagnosis, Epidemiology, Pathogenesis

Answer 5

Dx: FEVER > 5 DAYS plus some change in extremities (edema/red), polymorphous rash, conjunctivitis, lip cracking/strawberry tongue, cervical lymphadenopathy

E: highest in japan/asain americans, <5 y/o, M>F

P: no evidence, just systemic necrotizing vasculitis with predilection for coronary arteries

Question 6

KD disease course

Answer 6

Acute febrile phase: 10-14 days after URI/GI sx, fever/cutaneous sx, carditis/pericarditis/abd pain/irritability

Subacute phase (2-4 weeks): desquamation, arthritis (self-limiting), aneurysms due to vessel inflammation

Convalescent phase (months): asx but aneurysms may grow

Question 7

KD therapy and prognosis

Answer 7

TX: high does ASA/IVIG in first 10 days to decrease coronary involvement
IVIG KEY
Steroids/biologics if refractory to IVIG

Prognosis: 5% develop aneurysms, leading cause of CAD in children, early MI in young adults

Question 8

IgA Vasculitis

Epidemiology, Pathogenesis

Answer 8

E: most common child vasculitis, 3-15y/o, M>F, more in winter months

P: infectious trigger (Group A Strep), IgA-mediated dysregulated immune response to antigen, alternate complement tirggered, some HLA predisposition if genetic

Question 9

Clinical signs of IgAV

Answer 9

Palpable purpura - gravity-dependent
GI: Currant jelly stools, colicky abd pain (intermittent intense pain) - risk of intussusception - telescoping of small bowel
Arthralgia/Arthritis in 50-80% mainly lower extremities
Kidney involvement - hematuria, proteinuria
Subcutaneous periarticular edema

Question 10

Labs in IgAV

Answer 10

NO THROMBOCYTOPENIA
unremarkable
+IgA wth deposition in mesangial and GI vasculature
UA with high spot creatine and high BP

Question 11

Tx/Prognosis for IgAV

Answer 11

Tx: Sx - hydration, bland diet, analgesia, anti-inflammatories
Steroids for severe abd pain/arthritis
tx for other complications

Prognosis: recurrence less common/severe, runs course in 4-6 weeks, EXCELLENT prognosis

Question 12

Juvenile Dermatomyositis

Epidemiology, Dx

Answer 12

73% white, F>M, avg age 6.7years

Dx: RASH + symmetric proximal muscle weakness, high skeletal muscle enzymes in serum, myositis findings in EMG, muscle biopsy/MRI findings

Question 13

JDM

Etiology, Pathogenesis

Answer 13

E: environment + genetic
environ: UV exposure, maybe infection
genetic: DQAI*0501, TNFa polymorphisms
antibodies specific to myositis

P: Immune complexes activate endothelial cells - damaged by complement activation (due to IC deposition) - release of vWF = occlusion of arterioles and capillaries = infarction of local tissue

Question 14

JDM Histology

Answer 14

Perifascular Atrophy (small fibrils on edges)
Perivascular Infiltrate (lymphocytic)

Question 15

JDM Clincal Signs

Answer 15

Skin: Rash, sun exposed areas
Gottron’s Papules: over MCP, IP, elbow joints, red pink scaly papules
Heliotrop Rash: periorbital violaceous erythema

Muscle: proximal muscle weakness, Gower’s sign (difficult risking form floow), neck flexion weakness, abdominal weakness

Question 16

JDM Labs/Imaging

Answer 16

Labs: High muscle enzymes (CK, Aldolaste, LDH, AST, ALT)
Normal ESR/CRP, RF Negative
Myositis specific antibodies

MRI/Biopsy: inflammation, necrosis, fibrosis

Question 17

JDM Tx/Prognosis

Answer 17

Tx: Oral/IV Corticosteroids, MTX
Other steroid sparing immunosuppressants
IVIG for skin disease
HCQ for skin disease and prevention of photosensitivity flares

P: 1% mortality, High CV morbidity, variable disease course