This calculator is for general information and education. It is not medical advice and does not replace the judgment of a doctor, nurse or pharmacist who knows the full clinical picture.
A child with several days of high fever, red eyes, red lips and a rash should be seen by a doctor the same day.
What is Kawasaki disease?
Kawasaki disease is an inflammation of medium-sized blood vessels that mainly affects children under 5. It was first described by the Japanese pediatrician Tomisaku Kawasaki in 1967. Its cause is still unknown. Without treatment, about a quarter of children develop dilations of the coronary arteries, called aneurysms, which can lead to heart attacks years later. It is the leading cause of acquired heart disease in children in developed countries.
The principal clinical features
The 2017 American Heart Association scientific statement lists five principal features, in addition to fever:
- redness of both eyes, without discharge;
- changes of the lips and mouth: red, cracked lips, strawberry tongue, redness of the mouth and throat;
- a rash, which can take many forms but is not made of blisters;
- changes of the hands and feet: redness and swelling early, peeling around the nails in the second or third week;
- a swollen lymph node in the neck, at least 1.5 cm, usually on one side.
The features do not all appear at the same time, so they should be looked for over the whole course of the illness.
How the calculator classifies
| Situation | Result |
|---|---|
| fever ≥ 5 days and ≥ 4 features | complete Kawasaki disease |
| fever ≥ 5 days and 2 or 3 features | possible incomplete form |
| fever 4 days and ≥ 4 features | possible early diagnosis |
| infant ≤ 6 months with fever ≥ 7 days | evaluate for incomplete form |
| otherwise | criteria not met at this stage |
For a possible incomplete form, the AHA algorithm checks CRP and ESR: if they are raised, supplemental lab findings (anemia, high platelets after day 7, low albumin, raised ALT, white cells in the urine) or an abnormal echocardiogram support treatment.
Treatment
Treatment combines intravenous immunoglobulin, 2 g/kg in a single infusion, and aspirin. Given within 10 days of fever onset, it lowers the risk of coronary aneurysms to about 4%. Every child has an echocardiogram at diagnosis and again during follow-up.
Limits
Many illnesses mimic Kawasaki disease, including scarlet fever, viral infections, measles and drug reactions, as well as the multisystem inflammatory syndrome in children (MIS-C) that follows COVID-19. This tool helps organize the criteria; only a medical evaluation can make the diagnosis.