Definition and epidemiology
Kawasaki disease (KD) is an acute, self-limited medium-vessel vasculitis of childhood and the leading cause of acquired heart disease in children in developed countries. It predominantly affects children under 5 years (peak 6–24 months), with a male predominance. Incidence is highest in East Asian populations; in India it is increasingly recognised, with a likely seasonal (often winter–spring) clustering. The central concern is coronary artery aneurysm formation, which occurs in up to ~25% of untreated children versus ~4% when IVIG is given within the first 10 days of illness.
Clinical features
The hallmark is fever ≥5 days with mucocutaneous inflammation. The five principal clinical features are:
- Bilateral non-exudative bulbar conjunctival injection (limbal sparing typical)
- Oral mucosal changes — cracked/erythematous lips, strawberry tongue, diffuse oropharyngeal erythema
- Polymorphous exanthem (not vesicular or bullous)
- Extremity changes — acute palmar/plantar erythema and oedema; later periungual desquamation
- Cervical lymphadenopathy ≥1.5 cm, usually unilateral (the least common feature)
Irritability is often prominent. Perineal desquamation and reactivation/erythema at a prior BCG-scar site are useful supportive clues, the latter particularly relevant in BCG-vaccinated Indian infants.
Diagnostic criteria
Classic KD is diagnosed with fever ≥5 days plus ≥4 of the 5 principal features (or fewer if coronary changes are already present). Incomplete KD should be considered in a child with fever ≥5 days and only 2–3 features, or in an infant <6 months with prolonged unexplained fever; here supplementary laboratory criteria (CRP ≥3 mg/dL and/or ESR ≥40 mm/h, plus ≥3 of: anaemia for age, platelets ≥450,000 after day 7, albumin ≤3.0 g/dL, ALT elevation, leukocytosis ≥15,000, sterile pyuria) and echocardiography drive the decision per the AHA 2017 incomplete-KD algorithm. KD remains a clinical diagnosis — there is no confirmatory test, and alternative diagnoses (measles, scarlet fever, staphylococcal/streptococcal toxin-mediated disease, DRESS, systemic JIA, MIS-C) must be considered.
See the full criteria: Kawasaki Disease
Red flags
- Any coronary artery Z-score ≥2.5 or aneurysm on echocardiography
- Infants <6 months (higher coronary risk, frequently incomplete presentations)
- IVIG resistance — persistent or recrudescent fever ≥36 h after IVIG
- Signs of shock (Kawasaki disease shock syndrome) or macrophage activation syndrome
- Features overlapping MIS-C in a child with recent SARS-CoV-2 exposure
Management overview
Initial treatment is IVIG 2 g/kg as a single infusion plus aspirin, ideally within 10 days of fever onset (and still indicated beyond day 10 if fever or coronary changes persist). Aspirin is given at moderate-to-high anti-inflammatory dose (commonly 30–50 mg/kg/day in India; up to 80–100 mg/kg/day in some North American protocols) until afebrile, then switched to low antiplatelet dose (3–5 mg/kg/day) continued ~6–8 weeks if no coronary involvement, or indefinitely with aneurysms. Adjunctive corticosteroids are reasonable for high-risk patients and for IVIG-resistant disease, where a second IVIG dose, steroids, or infliximab are options. Baseline and follow-up echocardiography (typically at diagnosis, ~2 weeks, and ~6 weeks) is essential; long-term cardiology follow-up is stratified by maximal coronary involvement.
References
- McCrindle BW, et al. Circulation. 2017;135:e927–e999 (AHA scientific statement).
- IAP Rheumatology Chapter consensus guidelines on Kawasaki disease, 2021.
- Nelson Textbook of Pediatrics, 21st ed.
Decision support for qualified clinicians only — verify against current primary guidelines and your clinical judgement.