Kawasaki Disease

Kawasaki disease (川崎症), also known as mucocutaneous lymph node syndrome, is an acute systemic vasculitis (inflammation of mostly medium-sized blood vessels) common in children aged 2 to 5. It is the most common cause of acquired heart disease in children in developed countries. The cause is still unknown but a yet unknown inciting agent is theorised. There are about 100 cases in Hong Kong every year. Kawasaki disease can cause inflammation of blood vessels throughout the body, with a predilection to affect the coronary (heart) arteries. In severe cases, coronary artery aneurysm may occur, leading to blood vessel rupture and death. Children aged 6 months to 5 years old have a higher risk for Kawasaki disease. Early recognition and initiation of treatment are the mainstay of management to prevent morbidity and mortality.

Cause of Kawasaki disease

The cause of Kawasaki disease is still unknown. The medical community generally believes it is related to exposure to certain substances. If a parent or sibling has been infected, the incidence rate will increase exponentially, but it is not contagious. It is known to increase the risk of kawasaki disease in children, including:

Children under 5 years old most at risk for kawasaki disease
Boys more likely to develop Kawasaki disease than girls
Children of Asian or Pacific Island ancestry, such as Japanese or Koreans, are more likely to develop the disease

Symptoms of Kawasaki disease

Kawasaki disease has a rapid onset and symptoms appear in three stages, namely: acute, subacute and convalescent.

The Acute Stage lasts from 1-2 weeks (up to 4 weeks if left untreated) and has the following symptoms:

Abrupt onset of high fever (above 38.3 degrees) that lasts for more than 5 days and persists even with medication
Rash or peeling of the skin between the chest and legs, genitals, or groin area
Swelling and redness on the palms and soles
Red eyes
Swollen glands in the neck
Inflammation of the throat, mouth, and lips
Swollen, bright red tongue

The Subacute Stage starts when the fever dissipates to about three weeks thereafter, it is characterised by:

Joint pain
Abdominal pain
Stomach problems, such as diarrhea and vomiting
Peeling of the skin of the hands and feet
Coronary aneurysm and thrombus formation is a serious complication in this stage

The Convalescent stage typically starts on subsidence/resolution of clinical signs, usually within three months of the onset of acute illness. “Beau’s lines”, characteristic transverse groove on the fingernails, can be noticed in patients on this stage.

How to diagnose Kawasaki disease

The doctor will conduct a physical examination and ask about the child's symptoms, asking if there is abrupt, high-grade fever of 5 days or more and at least 4 of the following symptoms:

Red eyes
Red lips and mouth
Redness and swelling of limbs
Skin rashes
Swollen lymph nodes

Other tests that may be needed include:

Blood test
ECG and echocardiogram
X-ray
Coronary angiography

Kawasaki disease treatment

Injection of high-dose intravenous immune globulin (IVIG)

Initiation of immune globulin therapy within 7-10 days of the onset of illness is the cornerstone of treatment and decreases the incidence of developing coronary artery aneurysm from 25% to 3-5%.

Oral aspirin – given together with immune globulin therapy as first-line treatment
Clopidogrel – alternative to aspirin for patients with hypersensitivity to aspirin and those at risk of developing Reye’s syndrome
Supportive care for the symptomatic treatment of fever, joint pain and inflammation

Over 50% of patients will have complete resolution of coronary artery lesions one to two years after recovery. For children with residual cardiac findings, regular monitoring of cardiac status (e.g. ECG, echocardiography) and long-term medication is recommended.

How to prevent Kawasaki disease

There are currently no preventive measures against Kawasaki disease, but a high index of suspicion, early diagnosis and treatment can lead to more favorable outcomes and avoidance of long-term cardiac complications.

OT&P Medical Advice

Kawasaki disease is an acute systemic vasculitis with an unknown cause. It is common in children aged 2 to 5 years old. It causes inflammation of blood vessels in the body with a predilection to affect the coronary arteries. Weakening of the walls of the coronaries can lead to a condition known as an aneurysm (ballooning) which can then rupture and cause death. The peak incidence of Kawasaki disease is in children aged 6 months to 5 years old. Parents should pay attention to the symptoms to facilitate early check-up, diagnosis and treatment. If you want to know more, you can make an appointment with a doctor for consultation.