Eduovisual
Pediatrics (System-Integrated)
Kawasaki disease: diagnosis and management
— Peak age 6 months to 5 years; ~80% of cases under age 5
— Highest incidence in children of Japanese/Korean ancestry; M:F ~1.5:1
— Winter–spring clustering; suspected infectious trigger in genetically predisposed host
— Any child with fever ≥5 days that is unresponsive to antipyretics, plus mucocutaneous findings
— Infant <6 months with prolonged unexplained fever and irritability — consider incomplete KD even without full criteria
— Toddler with fever, rash, red eyes, and a recent diagnosis of "viral syndrome" that isn't resolving
— Vasculitis preferentially targets coronary arteries; aneurysms develop in 15–25% of untreated cases vs ~4% with timely IVIG
— Three clinical phases: acute (1–2 wk, fever + inflammation), subacute (2–4 wk, desquamation, thrombocytosis, peak aneurysm risk), convalescent (up to 8 wk, normalizing labs)
— Outpatient pediatricians are often the first contact; missed or delayed diagnosis beyond day 10 of illness substantially raises CAA risk
— Decision point: when to refer urgently to ED vs admit directly for IVIG
Board pearl: The single most important intervention is IVIG within 10 days of fever onset (ideally within 7); this reduces CAA risk from ~25% to ~4%. If the stem gives you day 8 of fever with classic features, do not wait for more labs — admit and treat.
Key distinction: KD is a clinical diagnosis — no lab confirms it. Don't let a normal CBC or negative strep talk you out of it when criteria are met.
— Bilateral non-exudative conjunctivitis (limbal sparing)
— Oral mucosal changes: strawberry tongue, cracked/red lips, diffuse pharyngeal erythema (no exudate, no ulcers)
— Polymorphous rash: maculopapular, morbilliform, or scarlatiniform; truncal; often accentuated in groin
— Extremity changes: erythema/edema of palms and soles acutely; periungual desquamation in subacute phase
— Cervical lymphadenopathy: usually unilateral, ≥1.5 cm, often the least common feature
— High, spiking (often 39–40°C), minimally responsive to antipyretics
— Extreme irritability is a classic associated feature, especially in infants — out of proportion to exam
— Fever ≥5 days + 2–3 criteria + supportive labs OR coronary abnormalities on echo
— Especially consider in infants <6 months and children >8 years — these groups present atypically but have higher CAA risk
— BCG site erythema/induration — pathognomonic-leaning finding in vaccinated children
— Aseptic meningitis, arthritis/arthralgias, hydrops of gallbladder, sterile pyuria
— Anterior uveitis on slit lamp
— Day-by-day fever timeline (the 10-day window drives management)
— Prior empiric antibiotics that "didn't work" — common red herring
— Recent vaccinations (defer live vaccines after IVIG)
Step 3 management: When a parent calls the clinic about a child on day 4 of fever with red eyes and rash, do not reassure and wait — schedule a same-day visit and have a low threshold to send to the ED for echo and admission if criteria evolve.
Board pearl: Mnemonic CRASH and burn — Conjunctivitis, Rash, Adenopathy, Strawberry tongue, Hand/foot changes, + fever (burn) ≥5 days.
— Bilateral bulbar conjunctival injection without exudate; limbal sparing (clear ring around iris) is classic
— Anterior uveitis in ~70% — usually asymptomatic, supports diagnosis if seen
— Strawberry tongue (prominent fungiform papillae on erythematous base)
— Dry, fissured, erythematous lips; no oral ulcers (presence of ulcers/Koplik spots/exudate argues against KD)
— Polymorphous rash, often perineal accentuation with early desquamation in the diaper area (high-yield clue)
— Acute: brawny edema of hands/feet, often painful — refusal to bear weight
— Subacute (week 2–3): sheet-like periungual desquamation starting at fingertips
— Late (1–2 mo): Beau lines (transverse nail grooves)
— Usually unilateral cervical node ≥1.5 cm, firm, non-fluctuant; often misdiagnosed as bacterial adenitis that fails antibiotics
— Tachycardia out of proportion to fever
— Gallop, muffled heart sounds, or new murmur → suspect myocarditis (present in most acute cases) or pericardial effusion
— Hypotension/shock = Kawasaki disease shock syndrome (KDSS) — rare but life-threatening; mimics septic shock
— Check peripheral pulses and capillary refill; assess for signs of CHF
— Marked irritability, especially in infants
— Hepatomegaly with gallbladder hydrops can produce RUQ tenderness
CCS pearl: On a CCS-style case, order vitals, full cardiac exam, and pulse oximetry on arrival; if hypotensive, move to monitored bed, IV access ×2, fluid bolus, and stat pediatric cardiology consult before or during IVIG.
Key distinction: Exudative conjunctivitis, oral ulcers, or discrete intraoral lesions point away from KD — think adenovirus, measles, or Stevens-Johnson instead.
— CBC with differential: leukocytosis with left shift; anemia common; thrombocytosis (>450K) appears in week 2 (not acutely — thrombocytopenia acutely is a poor prognostic sign)
— ESR and CRP: both markedly elevated; CRP ≥3 mg/dL and/or ESR ≥40 mm/hr are entry criteria for incomplete KD evaluation
— CMP: hypoalbuminemia (<3 g/dL), transaminitis, hyponatremia
— Urinalysis: sterile pyuria (urethral, so catheterized specimen may be negative) — high-yield clue
— Anemia for age, platelets ≥450K after day 7, albumin ≤3 g/dL, ALT elevated, WBC ≥15K, urine WBC ≥10/hpf
— Baseline echo at diagnosis — but do NOT delay IVIG waiting for it
— Assess LAD and RCA z-scores, LV function, pericardial effusion, valvular regurgitation
— Z-score ≥2.5 in any coronary segment supports diagnosis even with incomplete features
— Repeat at 1–2 weeks and 4–6 weeks; more frequently if abnormalities found
— ECG: PR prolongation, low voltage, ST/T changes, arrhythmia
— BNP/NT-proBNP: elevated with myocarditis; sometimes used when diagnosis is unclear
— Blood and urine cultures, throat swab, viral PCR — to exclude mimics if presentation atypical
— No serologic test confirms KD; do not order ANCA, ANA routinely unless considering alternative vasculitis
Board pearl: Thrombocytosis is a week-2 finding. Early thrombocytopenia is rare and is a feature of KDSS or macrophage activation syndrome — both portend severe disease and IVIG resistance.
Step 3 management: In a febrile child meeting 3 of 5 criteria, order CRP/ESR — if elevated, proceed to echo + supportive labs per AHA incomplete KD algorithm rather than continuing to "watch and wait."
— Repeat echo at 1–2 weeks and 4–6 weeks; if aneurysms present, repeat at shorter intervals per cardiology
— CT coronary angiography or cardiac MRI/MRA: for older children with poor echo windows or for surveillance of distal/giant aneurysms
— Invasive coronary angiography: reserved for symptomatic ischemia or to guide intervention
— No involvement: z <2
— Dilation only: z 2 to <2.5
— Small aneurysm: z 2.5 to <5
— Medium aneurysm: z 5 to <10 (and absolute <8 mm)
— Large/giant aneurysm: z ≥10 or absolute ≥8 mm — highest thrombosis risk, requires lifelong management
— ~10–20% of patients are IVIG-resistant (persistent or recrudescent fever 36 hr after IVIG ends)
— Kobayashi/Egami scores are Japanese-derived risk models — less predictive in US/multiethnic populations but conceptually tested
— Predictors: age <12 mo, male, low Na, low albumin, high CRP, high ALT, neutrophilia, low platelets
— Persistent fever despite IVIG → reassess for alternative diagnosis (rickettsial, staphylococcal/streptococcal toxin-mediated illness, systemic JIA, MIS-C)
— Marked cytopenias, ferritin ≥500 → evaluate for macrophage activation syndrome (MAS)
— In a post-SARS-CoV-2 child, features may overlap; MIS-C tends to be older (median 8–9 yr), with prominent GI symptoms, shock, and myocardial dysfunction — treatment overlaps but workup includes SARS-CoV-2 serology/PCR
Key distinction: A z-score ≥2.5 alone qualifies as KD when fever ≥5 days is present, even without classic criteria — this is diagnostic shortcut in incomplete cases.
Board pearl: Giant aneurysms (z ≥10 or ≥8 mm) virtually never fully regress and define the highest-risk population requiring dual antiplatelet + anticoagulation.
— Admit for IV therapy and monitored cardiac care
— Baseline echo (do not delay IVIG)
— IVIG + aspirin as soon as diagnosis is made, ideally within 10 days of fever onset
— Pediatric cardiology consult
— Persistent fever without alternative explanation
— Ongoing systemic inflammation (elevated CRP/ESR)
— Coronary artery abnormalities on echo
— High-risk features at presentation: age <12 mo, shock (KDSS), aneurysms already present on baseline echo, hyponatremia, marked transaminitis, MAS features
— These patients benefit from upfront adjunctive corticosteroids (RAISE trial paradigm) or infliximab in addition to IVIG
— Level 1 (no involvement): low-dose ASA × 6 wk, no long-term therapy
— Level 2 (dilation only, resolved): no long-term therapy
— Level 3 (small aneurysm): low-dose ASA indefinitely
— Level 4 (medium): ASA ± clopidogrel
— Level 5 (large/giant or current/prior thrombosis): ASA + anticoagulation (warfarin or LMWH)
— Levels 1–2: no restrictions
— Level 3+: restrict high-intensity competitive sports; individualized stress testing
Step 3 management: A 3-year-old on day 6 of fever meeting 4/5 criteria → admit, baseline echo, IVIG 2 g/kg over 10–12 hr, high-dose aspirin, cardiology consult. Do not send home for outpatient follow-up; do not start steroids reflexively unless high-risk features present.
Board pearl: The window of opportunity is fever days 5–10. Treating within this window changes the natural history; treating late still helps if inflammation/coronary changes persist.
— Dose: 2 g/kg as a single infusion over 10–12 hours
— Mechanism: immunomodulation (Fc receptor blockade, cytokine modulation)
— Premedicate or slow rate for infusion reactions; monitor for fluid overload (volume load is significant — caution in myocarditis with reduced EF)
— Hemolytic anemia is the most clinically relevant side effect; check Hgb 5–7 days post-infusion
— Defer live vaccines (MMR, varicella) for 11 months after IVIG
— High-dose (anti-inflammatory): 80–100 mg/kg/day divided q6h until afebrile 48–72 hr (US practice); some centers use moderate-dose 30–50 mg/kg/day
— Low-dose (antiplatelet): 3–5 mg/kg/day once daily, continued for 6–8 weeks minimum, then stopped if no coronary involvement; continued indefinitely if aneurysms persist
— Reye syndrome risk is low but real — hold aspirin and use clopidogrel if active influenza or varicella exposure
— Upfront for high-risk: prednisolone 2 mg/kg/day tapered over 2–3 weeks (RAISE protocol) plus IVIG and ASA
— Pulse methylprednisolone for refractory disease
— Second dose of IVIG 2 g/kg, OR
— Infliximab 5 mg/kg IV (TNF-α inhibitor) — increasingly preferred for speed and efficacy, OR
— High-dose IV methylprednisolone pulse
— Refractory beyond this: cyclosporine, anakinra, or cyclophosphamide per rheumatology
— ASA + warfarin (INR 2–3) or ASA + LMWH; DOACs are emerging but not first-line in pediatrics
Board pearl: Hold the aspirin, not the IVIG, if influenza is suspected — substitute clopidogrel for antiplatelet coverage.
Key distinction: IVIG dose is weight-based and fixed (2 g/kg) — not titrated. Aspirin transitions from anti-inflammatory to antiplatelet dosing once afebrile.
— Product selection matters in IgA deficiency — use IgA-depleted preparations to avoid anaphylaxis
— Aseptic meningitis, acute kidney injury (especially sucrose-containing products), thromboembolism (rare), and hemolytic anemia in non-O blood types are key adverse effects
— Repeat echo at 1–2 weeks regardless of clinical response
— Primary adjunctive use (with IVIG + ASA at diagnosis) in high-risk patients reduces CAA risk and IVIG resistance
— Indications to consider upfront steroids:
▸ Age <12 months with high inflammatory burden
▸ Coronary aneurysms on initial echo
▸ KDSS or marked hypotension
▸ High clinical prediction scores in appropriate populations
— Avoid steroid monotherapy — must combine with IVIG
— 5 mg/kg single IV infusion; rapid defervescence, well tolerated
— Screen for latent TB before use when feasible (often deferred in acute setting given urgency)
— Increasingly first-choice rescue therapy in US centers over second IVIG
— Used in IVIG/infliximab-refractory disease, especially with MAS overlap
— Daily SC dosing; short half-life allows quick titration
— Small (z 2.5 to <5): low-dose ASA alone, indefinitely while aneurysm persists
— Medium (z 5 to <10): low-dose ASA + clopidogrel (dual antiplatelet)
— Large/giant (z ≥10 or ≥8 mm): low-dose ASA + systemic anticoagulation (warfarin INR 2–3 or LMWH)
— Acute coronary thrombosis: thrombolysis (tPA), heparin, or PCI per pediatric cardiology
— Catheter-based PCI for focal stenoses; stenting controversial in growing children
— CABG preferred for severe multivessel disease in children, using internal mammary artery grafts (grow with patient)
— Cardiac transplantation for end-stage ischemic cardiomyopathy
CCS pearl: For refractory KD on day 3 after first IVIG with persistent fever and rising CRP, the next step on the orders sheet is second-dose IVIG 2 g/kg OR infliximab 5 mg/kg plus a repeat echo, not a sepsis workup repeat unless clinically indicated.
— Acute kidney injury can occur from KD-associated vasculitis, hemodynamic compromise (KDSS), or IVIG itself
— Prefer sucrose-free IVIG preparations to reduce osmotic nephropathy risk
— Hydrate adequately before and during IVIG; monitor urine output and creatinine
— Sterile pyuria is common and does NOT indicate renal injury — do not treat as UTI
— Transaminitis is part of KD itself (supportive criterion in incomplete KD)
— Gallbladder hydrops may produce RUQ pain, jaundice — usually self-limited, supportive care
— Significant hepatic dysfunction warrants evaluation for MAS overlap (ferritin, fibrinogen, triglycerides)
— Aspirin metabolism may be affected; monitor for salicylism (tachypnea, tinnitus, metabolic acidosis)
— Myocarditis is nearly universal subclinically; reduced EF on echo or KDSS warrants:
▸ Cautious IVIG infusion (slower rate, monitor for volume overload)
▸ Inotropic support if needed (milrinone preferred over high-dose epinephrine when feasible)
▸ Consider diuretics for pulmonary edema, but avoid hypoperfusion
— High-dose aspirin and antiplatelet therapy require attention to baseline bleeding risk
— Coordinate with hematology if transfusion-dependent or known platelet dysfunction
— Diagnosis remains clinical; treatment proceeds with IVIG and ASA
— Consider broader infectious workup before steroid escalation
— IVIG-associated hemolysis can be more severe; monitor closely
Board pearl: Don't treat sterile pyuria with antibiotics in suspected KD — it's a supportive feature, not infection. Catheterized specimens may miss it (urethritis origin).
Step 3 management: Before IVIG, document baseline Hgb, Cr, LFTs; recheck Hgb 5–7 days later, as delayed hemolytic anemia is the most common clinically significant IVIG complication.
— Highest risk for incomplete presentation and coronary aneurysms
— May present only with prolonged fever and irritability — extreme vigilance required
— Any infant <6 months with fever ≥7 days without source plus elevated CRP/ESR warrants echocardiography per AHA
— BCG-site reaction (in vaccinated infants) is a particularly useful clue
— Also at higher risk of atypical presentation and delayed diagnosis
— Often initially misdiagnosed as streptococcal disease, viral exanthem, or systemic JIA
— Consider KD in any school-age child with prolonged fever and elevated inflammatory markers without source
— Recurrence rate ~3% (higher in Japan)
— Typically within 1–2 years of initial episode; same treatment approach
— Recurrence does not necessarily portend coronary involvement, but echo surveillance is mandatory
— Women with prior giant aneurysms have higher cardiovascular risk in pregnancy and delivery
— Preconception counseling and high-risk obstetric/cardiac co-management
— Antiplatelet/anticoagulation regimens adjusted (warfarin contraindicated in first trimester — switch to LMWH)
— Patients with persistent CAA require structured transition to adult cardiology
— Lifelong follow-up with periodic imaging, lipid management, and cardiovascular risk reduction
— Older children (median 8–9 yr) with prominent GI symptoms, shock, and recent SARS-CoV-2 exposure favor MIS-C
— Treatment overlaps (IVIG, steroids) but workup differs
Key distinction: In infants <6 months, the threshold to obtain echocardiography is dramatically lower — fever + elevated inflammatory markers can be sufficient indication even without classic features.
Board pearl: Recurrent KD does occur and the management approach is identical; a history of prior KD does not exempt the child from re-treatment with IVIG.
— Dilation, aneurysms (saccular or fusiform), thrombosis, stenosis
— Peak detection at 2–8 weeks after fever onset
— Giant aneurysms (z ≥10 or ≥8 mm) rarely regress; lifelong thrombosis and MI risk
— Late complications: ischemic cardiomyopathy, sudden cardiac death in young adulthood
— Present in most acute cases (often subclinical); can cause CHF, arrhythmia
— Improves with IVIG and treatment of underlying inflammation
— ~5% of cases; presents with hypotension, decreased perfusion
— Higher risk of IVIG resistance, CAA, and MAS
— Requires ICU-level care, often upfront adjunctive steroids ± infliximab
— Rare but life-threatening overlap
— Cytopenias, ferritin >500 (often much higher), hypofibrinogenemia, hypertriglyceridemia, hepatosplenomegaly
— Treat with steroids, anakinra, cyclosporine
— Mitral regurgitation most common; usually transient
— Small effusions common; tamponade rare
— PR prolongation common acutely; later, ischemia-related arrhythmias in patients with CAA
— Axillary, iliac, renal arteries — uncommon but documented
— Hydrops of gallbladder, aseptic meningitis, arthritis, anterior uveitis, sensorineural hearing loss (rare)
— Endothelial dysfunction may persist even without aneurysms — emphasize lifelong cardiovascular health (BP, lipids, no smoking)
Board pearl: The highest-risk window for sudden death is in patients with giant aneurysms in the first 1–2 years post-diagnosis, due to thrombotic occlusion. Adherence to dual antithrombotic therapy is non-negotiable.
Step 3 management: New chest pain in an adolescent with prior KD and known aneurysms is acute coronary syndrome until proven otherwise — ECG, troponin, cardiology consult, and admit.
— Kawasaki disease shock syndrome (hypotension, poor perfusion)
— Significant myocardial dysfunction (low EF, evidence of CHF, arrhythmia)
— Large pericardial effusion or tamponade physiology
— MAS features (cytopenias, coagulopathy, organ dysfunction)
— Respiratory failure (rare; consider alternative diagnosis)
— Pediatric cardiology: mandatory at diagnosis for echocardiography interpretation and long-term management planning
— Pediatric rheumatology / infectious disease: for refractory disease or diagnostic uncertainty
— Hematology: for IVIG-resistant disease requiring complex antithrombotic regimens or MAS
— Cardiothoracic surgery: if giant aneurysms or thrombosis requiring intervention
— Continuous cardiac monitoring during infusion
— Strict I/O, daily weights — IVIG is a substantial volume load
— Vital signs q15min initial, then q1h; watch for infusion reactions
— Monitor for clinical improvement: defervescence typically within 36 hr
— Persistent or recurrent fever ≥36 hours after IVIG completion
— Rising CRP, new coronary abnormalities, worsening clinical state
— Action: cardiology and rheumatology re-evaluation; second IVIG vs infliximab
— Community hospital without pediatric cardiology or echo capability → transfer to tertiary center after stabilization and IVIG initiation if feasible
CCS pearl: For a hypotensive febrile child meeting KD criteria, the order set should read: PICU admit, continuous monitoring, two large-bore IVs, 20 mL/kg NS bolus(es), baseline echo and ECG, IVIG 2 g/kg, methylprednisolone IV, high-dose aspirin, peds cardiology consult stat.
Board pearl: The decision to treat does not require the echo result. Empiric IVIG + ASA while echo is being arranged is correct when clinical criteria are met.
— Quotidian fevers with evanescent salmon-pink rash, arthritis, lymphadenopathy, hepatosplenomegaly
— Conjunctivitis and extremity changes absent; ferritin often very high
— Treatment: NSAIDs, then IL-1/IL-6 biologics
— Medium-vessel vasculitis like KD, but more systemic with renal, GI, and neuro involvement
— Older patients, no mucocutaneous features of KD
— Treatment: steroids ± cyclophosphamide
— Palpable purpura on lower extremities/buttocks, arthritis, abdominal pain, IgA nephropathy
— Distinct rash distribution and morphology; not the polymorphous truncal rash of KD
— Large-vessel vasculitis, older adolescents/young adults
— Pulse deficits, BP discrepancies between extremities, claudication
— Post-SARS-CoV-2 hyperinflammatory state
— Older age, prominent GI symptoms, frequent shock and ventricular dysfunction
— Significant phenotypic overlap with KD; both treated with IVIG ± steroids
— Key distinction: SARS-CoV-2 exposure history, age >5, GI predominance
— Recurrent oral and genital ulcers, uveitis — KD has no ulcers
— Recurrent self-limited episodes; not the single prolonged fever of KD
— PFAPA: periodic fever, aphthous stomatitis, pharyngitis, adenitis — distinguished by recurrence and oral ulcers
Key distinction: Oral ulcers, exudative pharyngitis, or vesicular oral lesions essentially exclude KD. KD oral findings are erythema, strawberry tongue, and cracked lips — never discrete ulcers.
Board pearl: When a stem describes a 10-year-old with recent COVID, prominent diarrhea, shock, and reduced EF, lean toward MIS-C — but IVIG is still part of management. Phenotype overlap is real.
— Sandpaper rash, strawberry tongue, circumoral pallor, tonsillar exudate
— Rapid strep or throat culture positive; responds to penicillin within 24–48 hr
— Key distinction: tonsillar exudate and rapid antibiotic response — KD doesn't have either
— Fever, diffuse erythroderma, hypotension, multiorgan involvement, desquamation
— Source (tampon, surgical site, abscess) often identifiable; rapid hemodynamic deterioration
— Treat with source control, antibiotics, IVIG (overlapping therapy)
— Younger children, Nikolsky sign positive, perioral crusting; no significant conjunctivitis
— Cough, coryza, conjunctivitis (3 C's), Koplik spots, cephalocaudal rash
— Koplik spots are diagnostic and absent in KD; vaccination history matters
— Exudative conjunctivitis (vs non-exudative in KD), pharyngitis, often less ill-appearing
— Self-limited; viral PCR positive
— Tick exposure, petechial rash starting on wrists/ankles spreading centrally
— Empiric doxycycline regardless of age if suspected; do not delay
— Recent drug exposure (anticonvulsants, sulfa, allopurinol), eosinophilia, mucosal ulceration (SJS)
— Discrete bullae or epidermal detachment — not seen in KD
— Water/animal exposure, conjunctival suffusion, myalgia, hepatic/renal involvement
— Painful erythematous extremities, irritability — a historical mimic
Step 3 management: Always send a rapid strep + throat culture before committing to KD diagnosis in a school-age child with pharyngitis features, but do not delay IVIG if criteria are met and strep results pending.
Key distinction: Exudative pharyngitis or conjunctivitis, oral ulcers, vesicles, or Nikolsky sign should redirect the diagnostic thinking away from KD toward infectious mimics.
— Low-dose aspirin 3–5 mg/kg/day for minimum 6–8 weeks; continue indefinitely if any coronary involvement
— Additional antithrombotic therapy based on maximum z-score (clopidogrel for medium, warfarin/LMWH for large/giant)
— Provide pneumococcal and influenza vaccines per schedule (inactivated OK)
— Defer live vaccines (MMR, varicella, intranasal flu) for 11 months post-IVIG
— Counsel families: hold aspirin during active influenza or varicella; substitute clopidogrel temporarily
— Annual inactivated influenza vaccine for child and household contacts
— Level 1–2 (no/transient involvement): routine pediatric care; cardiovascular risk counseling; no restrictions
— Level 3 (small aneurysm): ASA indefinitely; annual cardiology follow-up; periodic echo and stress testing
— Level 4 (medium aneurysm): dual antiplatelet therapy; cardiology q6–12 months; advanced imaging
— Level 5 (large/giant aneurysm): ASA + anticoagulation; cardiology q3–6 months; advanced coronary imaging; restriction from high-intensity competitive sports
— Healthy diet, regular physical activity (level-appropriate)
— Avoid tobacco exposure including secondhand
— Annual BP screening; lipid screening per pediatric guidelines
— Maintain healthy BMI
— Structured handoff to adult cardiology for patients with persistent CAA
— Reproductive counseling for women with significant cardiac involvement
Step 3 management: At the post-discharge visit on day 14, transition high-dose aspirin to low-dose antiplatelet aspirin if afebrile ≥48–72 hr, confirm echo follow-up scheduled at 4–6 weeks, and update vaccine plan with 11-month deferral of live vaccines.
Board pearl: Children with no coronary involvement at 4–6 weeks AND 8 weeks can typically discontinue aspirin and resume normal activities, with cardiovascular risk counseling but no specific cardiac restrictions.
— Baseline at diagnosis (do not delay IVIG)
— 1–2 weeks after onset
— 4–6 weeks after onset
— If all normal at 4–6 weeks: no further routine echo; cardiovascular risk follow-up only
— If abnormal: ongoing surveillance per AHA risk level (every 6–12 months minimum, more frequent for larger aneurysms)
— Primary care visit 1–2 weeks post-discharge to assess defervescence, desquamation, medication adherence
— Pediatric cardiology follow-up timed with echo
— Lab follow-up: CBC (delayed IVIG hemolysis), CRP/ESR trending toward normal
— While on dual antiplatelet/anticoagulation: avoid contact sports and activities with high head-injury risk
— Stress testing prior to clearing competitive athletics in patients with any history of aneurysm
— Inactivated vaccines on schedule
— Live vaccines (MMR, varicella) deferred 11 months post-IVIG (IVIG-derived antibodies blunt response)
— Annual inactivated influenza for child and household; consider COVID-19 vaccine per current guidance
— Influenza vaccine especially important due to aspirin/Reye risk
— Recognize symptoms of recurrence and seek care promptly
— Recognize symptoms of myocardial ischemia (chest pain, syncope, exercise intolerance) — call EMS
— Aspirin compliance and timing of clopidogrel substitution during viral illness
— Avoid NSAIDs other than aspirin (can blunt aspirin's antiplatelet effect and increase bleeding)
— Chronic disease support for families of children with giant aneurysms
— School coordination for medication administration and activity modification
Board pearl: Live vaccines must be deferred 11 months after IVIG. This often necessitates rescheduling MMR/varicella that would have been given around age 1; document clearly in the chart and remind the family at each visit.
Step 3 management: Annual influenza vaccination is doubly important in KD survivors — it protects against influenza-triggered Reye risk associated with their aspirin therapy.
— Blood-derived product — explicit consent required, including discussion of infection risk (extremely low with modern processing) and hemolysis
— Religious objections (e.g., some Jehovah's Witness families): IVIG is generally considered acceptable in many traditions but not universally; engage chaplaincy, ethics consult, and family early
— Pediatric assent for older children should be sought
— Parental refusal of IVIG in confirmed KD is a high-stakes scenario: untreated CAA risk is ~25%, with potential for sudden death
— Document risk discussion thoroughly; engage ethics committee
— If refusal persists and child is at imminent risk, contact child protective services and seek court-ordered treatment — medical neglect framework applies
— A leading source of pediatric malpractice claims: febrile child with KD features dismissed as viral, later presents with MI
— Document the differential, criteria checked, and follow-up plan at each visit; safety-net counseling is critical
— Telephone triage notes should reflect symptom timeline and return precautions
— Discharge handoff must clearly communicate: medication regimen (aspirin dose, clopidogrel/warfarin if applicable), echo follow-up date, live vaccine deferral, and signs of recurrence or ischemia
— Adolescent-to-adult cardiology transition is a known vulnerable point; structured transition programs reduce loss to follow-up
— KD is not federally reportable but is tracked by many state and academic surveillance systems
— Report suspected MIS-C per current CDC/state guidance
— Aspirin in children: counsel families on Reye risk; consider medical alert documentation
— Warfarin management: regular INR monitoring, dietary counseling, fall precautions
— KD disproportionately affects children of Asian-Pacific Islander ancestry; ensure equitable access to specialty echo and IVIG, particularly in under-resourced settings
Board pearl: Parental refusal of life-saving treatment for a minor with a treatable condition like KD with high CAA risk is a recognized indication to invoke medical neglect protocols with hospital ethics and legal involvement — this is a classic Step 3 ethics stem.
Board pearl: A two-second mental algorithm: fever ≥5 days + ≥4 mucocutaneous features → IVIG + aspirin + echo + admit + cardiology, regardless of viral testing results or "improvement on antibiotics."
Key distinction: Adenopathy is the least sensitive of the 5 principal criteria — its absence should not steer you away from KD.
— 3-year-old with 6 days of high fever, bilateral non-exudative conjunctivitis, strawberry tongue, polymorphous truncal rash, swollen hands. CBC: WBC 18K, platelets 480K, CRP 12. Question: Best next step? Answer: IVIG 2 g/kg + high-dose aspirin + echocardiogram + admit.
— 5-month-old with 7 days of fever, irritable, only conjunctivitis and rash. CRP 8, albumin 2.8, ALT 90, platelets 520K. Question: Best next step? Answer: Echocardiogram and treat as KD (incomplete criteria + supportive labs meet algorithm).
— Child completed IVIG 48 hours ago, fever recurred today. Question: Best next step? Answer: Second IVIG dose 2 g/kg OR infliximab 5 mg/kg.
— Child with KD features and hypotension, cool extremities, low EF on echo. Question: Best initial management? Answer: Fluid resuscitation cautiously, IVIG, adjunctive corticosteroids, PICU admission, inotropic support.
— Child received IVIG 2 months ago and is due for MMR. Question: Best next step? Answer: Defer MMR until 11 months post-IVIG.
— Child on chronic aspirin for prior KD with small aneurysm now has influenza. Question: Best management? Answer: Hold aspirin, substitute clopidogrel, treat influenza, resume aspirin when recovered.
— Child with giant aneurysm, due for sports physical. Question: Best recommendation? Answer: Restrict from high-intensity competitive sports; stress test prior to clearance; continue ASA + anticoagulation.
— 10-year-old with recent COVID, prominent diarrhea, shock, reduced EF, conjunctivitis, rash. Question: Most likely diagnosis? Answer: MIS-C, but treatment overlaps (IVIG ± steroids).
— Parents refuse IVIG citing personal beliefs; child meets all criteria. Question: Best next step? Answer: Engage ethics consultation; if refusal persists, involve hospital legal/CPS for court-ordered treatment under medical neglect framework.
— Child completed IVIG, afebrile, going home. Question: Most appropriate plan? Answer: Low-dose aspirin × 6–8 weeks, echo at 1–2 weeks and 4–6 weeks, defer live vaccines 11 months.
Board pearl: Recognize that IVIG + aspirin + echo + admit is the most common single correct answer choice; secondary stems test you on follow-up details (vaccine timing, Reye risk, refractory management, transition).
Kawasaki disease is a clinically diagnosed medium-vessel vasculitis of young children defined by ≥5 days of fever plus mucocutaneous findings, treated urgently with IVIG 2 g/kg and aspirin within 10 days of fever onset to prevent coronary artery aneurysms — the central, lifelong determinant of prognosis.
Board pearl: When in doubt about whether to treat — treat. The risk of missing KD (25% CAA rate, potential sudden death) far exceeds the risk of empiric IVIG in a febrile child meeting clinical criteria.