Kawasaki disease (KD) was first reported from Japan in 1967 by a young pediatrician, Tomisaku Kawasaki, while working at the Red Cross Hospital in Tokyo. Kawasaki disease is a children’s illness. It’s also known as Kawasaki syndrome or mucocutaneous lymph node syndrome. About 75 percent of people with it are under age 5. Boys develop the illness almost twice as often as girls. In the United States, it’s more frequent among Asian-American children, but it occurs in children of all races and ethnicities.
What are the common symptoms of Kawasaki disease?
• Fever (ranging from 101 to above 104)
• Rash on back, chest, and abdomen
• Swollen, red hands and feet
• Bloodshot eyes
• Swollen lymph glands in the neck
• Irritation and swelling of the mouth, lips and throat
What causes it?
Doctors don’t know what causes it. It doesn’t appear to be hereditary or contagious. Sometimes more than one child in a family can develop it, which may indicate a genetic predisposition for Kawasaki disease.
The diagnosis is made by the presence of fever for at least 5 days (onset of fever considered day one of illness) and at least four out of the following five diagnostic criteria that often appear sequentially:
• Conjunctiva injection – redness without exudate, typically bilateral with perilimbal sparing (a ring of normal conjunctiva around the iris). This appears early in the illness and due to its transitory nature should be sought on history as well as clinical examination. Photophobia and eye pain are seldom present
• Erythema of oral and/or pharyngeal mucosa – may include strawberry tongue, red pharynx and/or red and cracked lips, but no tonsillar exudates or ulcers
• Erythema and oedema of hands and feet – this is a common feature but may only manifest as failure or refusal to weight-bear. In the subacute phase of Kawasaki disease (from about day 10 onward), there may be desquamation of the fingers and toes
• Polymorphous skin rash – usually begins in the nappy area (where there may be desquamation early in the disease) and spreads to involve the trunk, extremities and face. Rash may be maculopapular, annular or scarlatiniform. Nonblanching or vesicular rashes are not usually seen
• Cervical lymphadenopathy – often unilateral and large, with node size greater than 1.5 cm. This is the least frequently seen criteria, but is more common in older children.
Kawasaki disease should be suspected in any child with a persistent fever with no other likely explanation. The pyrexia associated with Kawasaki disease is typically high (often greater than 39°C), remittent and unresponsive to antibiotic therapy, and usually also unresponsive to antipyretics. This pattern of fever may help to distinguish Kawasaki disease from a common viral exanthem.
Rash and peeling (desquamation) of the nappy area rash is common in the acute phase. Periungal (fingers and toes) desquamation appears 1–3 weeks after fever onset (convalescent phase), by which time treatment would be delayed. The clinical features may develop over days and are not always present concurrently. Frequent review and careful and repeated history, specifically asking about suggestive features, are important in making the diagnosis.
Extreme irritability – more so than in other febrile illnesses – is characteristic of Kawasaki disease. Other suggestive features include inflammation of a recent Bacille Calmette-Guerin (BCG) scar and sterile pyuria (leucocytes on urine microscopy but sterile by standard culturing techniques).
Features that make the diagnosis less likely include non-blanching rash, bullous or vesicular lesions, oral ulceration, generalized lymphadenopathy, and a prompt response to antibiotics. General practitioners should not wait for the fever to persist and may make the diagnosis and referral before 5 days if other clinical features are present, prompting a strong index of suspicion.
Complications of Kawasaki disease usually affect the heart. Your child will need tests to check their heart is functioning normally.
• Electrocardiogram (ECG) – measures electrical activity
• Echocardiogram (echo) – uses ultrasound to produce pictures of the heart If no treatment is given, around 25% of children develop swelling of the blood vessels around the heart (coronary arteries). The risk is reduced to 5% if treated with immunoglobulin.
In some cases this swelling can progress to weakened areas of the blood vessels called aneurysms. These can cause a blood clot to develop or in rare cases can burst. They can also increase the risk of a heart attack. If an aneurysm develops, long term treatment and follow up is needed.
How is Kawasaki disease treated?
Kawasaki disease is typically treated in the hospital at least while the child receives initial treatment. The stay is usually a few days up to a few weeks. The standard initial treatment is aspirin and intravenous immunoglobulin (IVIG). Aspirin is used to reduce fever, rash, joint swelling and pain. It can also help prevent blood clots from forming. IVIG, when given early in the illness, can reduce the risk of developing coronary artery abnormalities. Other medications such as steroids or infliximab may be used in children who do not respond to IVIG.