Kawasaki Disease Criteria Calculator

Classic Kawasaki Disease (KD) requires fever for ≥5 days plus at least 4 of 5 principal features: bilateral nonexudative conjunctivitis, oral changes (e.g., strawberry tongue, cracked lips), polymorphous rash, extremity changes (erythema/edema or periungual peeling), and cervical lymphadenopathy ≥1.5 cm (usually unilateral).

The score here tallies principal features but does not replace full AHA pathways. Infants and older children can present incompletely; maintain suspicion when fever persists and the exam evolves over several days.

1. Confirm fever duration/timeline and assess all five principal KD features with exam timing.
2. If classic criteria are incomplete, apply AHA incomplete KD laboratory and echocardiography pathways promptly.
3. Obtain baseline echo and inflammatory labs, then involve cardiology early when suspicion remains high.
4. Start IVIG/aspirin treatment without delay when criteria are met or coronary findings support diagnosis.
5. Schedule follow-up imaging and explicit return precautions before discharge or observation handoff.

If fever ≥5 days with only 2–3 features, follow incomplete KD algorithms. Obtain CRP/ESR; if inflammatory markers are elevated (e.g., CRP ≥3 mg/dL or ESR ≥40), add supplemental labs: anemia for age, platelet count (thrombocytosis after day 7), albumin <3 g/dL, elevated ALT, WBC >15K, and sterile pyuria. Positive supplemental labs or coronary changes on echocardiography support treatment. Low inflammatory markers with normal echo favor observation and re-exam.

Infants <6 months with unexplained fever ≥7 days warrant low threshold for echo even with few clinical features. Document serial exams—features can appear sequentially.

• Waiting for all five principal features before initiating incomplete KD workup.
• Delaying echocardiography when inflammatory markers are elevated but exam is evolving.
• Underestimating KD in infants with prolonged fever and limited mucocutaneous findings.
• Missing structured 36-48 hour post-IVIG reassessment for potential IVIG resistance.

• Persistent or recrudescent fever 36-48 hours after IVIG suggesting IVIG resistance.
• New hemodynamic instability, myocarditis concern, or coronary abnormalities on imaging.
• Rapidly evolving mucocutaneous findings with rising inflammatory markers despite uncertain initial classification.
• Concern for MIS-C overlap or alternate high-risk inflammatory syndrome.

• During active inpatient evaluation: serial fever and perfusion reassessment in each care block.
• Post-IVIG: explicit 36-48 hour reassessment for fever resolution and inflammatory trajectory.
• After discharge or observation: strict short-interval follow-up with repeat echo/labs per pathway.

• IVIG 2 g/kg as a single infusion ideally within 10 days of fever onset; treat earlier if compelling suspicion or coronary involvement.
• Aspirin per local protocol (often 30–50 or 80–100 mg/kg/day divided QID acutely, then 3–5 mg/kg/day once afebrile and after IVIG); verify current guidance.
• Consider corticosteroids for high-risk profiles (e.g., certain risk scores, shock, or IVIG resistance risk per local protocols).
• Reassess at 36–48 hours post-IVIG; persistent or recrudescent fever suggests IVIG resistance—consult cardiology/ID for second IVIG, steroids, or infliximab per pathway.

Vaccinations (live vaccines) are typically deferred after IVIG—coordinate follow-up with primary care. Educate caregivers about Reye concerns with aspirin and viral exposures.

Echocardiography at diagnosis, then typically at ~1–2 weeks and 4–6 weeks. High-risk or aneurysmal changes prompt more frequent imaging and cardiology-directed follow-up. Track Z-scores for coronary dimensions. Obtain baseline ECG; consider troponin/BNP if myocarditis is suspected.

• Counsel families on chest pain, dyspnea, syncope, or exercise intolerance as return precautions.
• Encourage adherence to antiplatelet therapy and cardiology appointments; provide written plans when possible.

• MIS-C, adenovirus, EBV/CMV, scarlet fever, SJS/TEN, drug eruptions, staph/strep TSS, JIA, and measles are key differentials.
• Shock, severe GI symptoms, lymphopenia, or elevated cardiac markers should prompt MIS-C pathways and ID/rheum involvement.
• Unilateral, purulent conjunctivitis or exudative pharyngitis/pus suggests alternate etiologies.

When in doubt, involve cardiology and ID early; start treatment if the gestalt is high, rather than await four textbook features.

• Admit when treating or when incomplete KD workup is ongoing; ensure IV access and monitoring for IVIG reactions.
• For observation (low suspicion, normal labs/echo), schedule rapid reassessment; provide strict return precautions for new rash, swelling, mucosal changes, or persistent fever.
• Explain the purpose of serial exams and echocardiograms. Clarify that features may evolve and that early therapy lowers coronary risk.
• Document shared decision-making, discussion of aspirin risks, and planned follow-up intervals.

• Fever timeline and principal feature count with exam-date evolution.
• Incomplete-KD lab pathway status and echocardiography findings.
• Treatment timing (IVIG, aspirin, adjuncts) and post-treatment reassessment window.
• Current differential (KD vs MIS-C/other) and consult-team recommendations.
• Follow-up echo schedule, return precautions, and escalation trigger.

• Fever day count, principal-feature timeline, and incomplete-KD pathway branch used.
• Key labs and trend direction (CRP/ESR, CBC/platelets, albumin, ALT, UA).
• Echo/ECG findings with most recent coronary Z-score context if available.
• Therapy delivered (IVIG/aspirin/adjuncts) and exact post-treatment fever timeline.
• Decision needed from specialist team (second-line therapy, imaging interval, level of care).

• Fever onset date and duration, plus all five principal features with timing.
• Incomplete KD labs (CRP/ESR, CBC, albumin, ALT, urinalysis) and echo findings.
• Treatment timing (IVIG dose, aspirin plan) and consults.
• Follow-up echo schedule and caregiver return precautions.

• Pediatric Vital Signs
• Pediatric Blood Volume
• Transfusion Volume
• PSIRS
• Attia Pharyngitis Predictor
• Centor/McIsaac

• AHA Scientific Statement: Diagnosis, Treatment, and Long-Term Management of Kawasaki Disease (2017).
• McCrindle BW et al. AHA Scientific Statement on Kawasaki Disease. Circulation. 2017.