Kawasaki Disease

Kawasaki Disease (KD), also known as mucocutaneous lymph node syndrome, is a rare but serious illness that primarily affects children under the age of five. First described by Dr. Tomisaku Kawasaki in 1967, the disease causes inflammation in the walls of medium-sized arteries throughout the body, especially the coronary arteries that supply blood to the heart.

Though the exact cause remains unknown, KD is the leading cause of acquired heart disease in children in many developed countries. Fortunately, if diagnosed and treated early, most children recover without long-term complications.

In this blog, we’ll cover everything you need to know about Kawasaki Disease, including its symptoms, causes, complications, diagnosis, treatment options, and prevention strategies.

What is Kawasaki Disease?

KD is an acute febrile illness that leads to inflammation of blood vessels, lymph nodes, skin, and mucous membranes. It typically occurs in children between 6 months and 5 years of age, but older children and, rarely, adults can also develop the disease.

The condition progresses through different phases, beginning with a high fever and followed by characteristic symptoms such as rash, swollen lymph nodes, red eyes, and changes in the mouth and extremities.

If left untreated, it can cause coronary artery aneurysms, which may lead to heart complications later in life.

Who is at Risk?

While it can affect anyone, certain factors increase the risk:

• Age: Most common in children under 5 years.

• Gender: Boys are slightly more likely to be affected than girls.

• Ethnicity: Higher prevalence in children of Asian descent, especially Japanese and Korean.

• Genetics: A family history of Kawasaki Disease may increase susceptibility.

Symptoms of Kawasaki Disease

Symptoms appear in phases:

1. Acute Phase (First 1–2 weeks)

• Persistent high fever (often above 39°C / 102°F) lasting more than 5 days

• Red eyes without pus or discharge

• Red, cracked lips and a “strawberry tongue”

• Rash (trunk and genital area)

• Swollen hands and feet, sometimes with redness of palms and soles

• Swollen lymph nodes, usually in the neck

2. Subacute Phase (Weeks 2–4)

• Peeling skin on hands and feet

• Joint pain

• Abdominal pain, vomiting, diarrhea

• Irritability

• Risk of heart complications increases in this stage

3. Convalescent Phase (Weeks 4–8)

• Symptoms gradually resolve

• Laboratory values return to normal

• Risk of complications persists until full recovery

Causes of Kawasaki Disease

The exact cause of KD is still unknown, but several theories exist:

1. Infectious Trigger – Some researchers believe bacteria, viruses, or other pathogens may trigger the disease in genetically susceptible children.

2. Genetic Factors – Certain gene variations are linked to an increased risk.

3. Immune System Abnormalities – Kawasaki Disease may involve an overactive immune response that attacks blood vessel walls.

4. Environmental Factors – Seasonal outbreaks suggest environmental triggers like toxins or allergens could play a role.

Complications of Kawasaki Disease

Without timely treatment, KD can cause severe complications, particularly involving the heart. These include:

• Coronary artery aneurysms (ballooning of blood vessel walls)

• Myocarditis (inflammation of the heart muscle)

• Pericarditis (inflammation of the sac around the heart)

• Arrhythmias (irregular heartbeat)

• Valvular heart disease

Early diagnosis and treatment reduce the risk of coronary artery complications from 25% to less than 5%.

How is Kawasaki Disease Diagnosed?

There is no single test to confirm KD. Doctors rely on clinical criteria and laboratory tests:

Clinical Diagnosis

• Fever lasting at least 5 days

• At least 4 of the following symptoms:

  • Rash

  • Swollen lymph nodes

  • Red eyes

  • Changes in lips/mouth

  • Swelling or redness in hands/feet

Laboratory Tests

• Blood tests (to check inflammation markers, anemia, or platelet counts)

• Urine tests (to rule out infections)

• Echocardiogram (to detect coronary artery abnormalities)

• Electrocardiogram (ECG) to check heart rhythm

Treatment of Kawasaki Disease

Prompt treatment is crucial to prevent complications. The main goals are to reduce inflammation and protect the heart.

1. Intravenous Immunoglobulin (IVIG)

• High-dose IVIG given within 10 days of fever onset is the standard treatment.

• Reduces the risk of coronary artery aneurysms significantly.

2. Aspirin Therapy

• High-dose aspirin is used initially to reduce inflammation and fever.

• Low-dose aspirin is continued for weeks to prevent blood clots.

3. Corticosteroids and Other Medications

• In children who don’t respond to IVIG, corticosteroids or biologic drugs (e.g., infliximab) may be used.

4. Long-term Follow-up

• Regular echocardiograms and check-ups are necessary to monitor heart health.

• Children with coronary complications may need lifelong monitoring.

Living with Kawasaki Disease

Most children recover completely with timely treatment. However, lifestyle adjustments may be necessary for those with heart complications:

• Healthy diet and exercise to maintain cardiovascular health

• Avoiding smoking exposure

• Regular heart check-ups

• Medications (like blood thinners) if coronary problems persist

Can Kawasaki Disease Be Prevented?

Currently, there is no known prevention for Kawasaki Disease. The best strategy is early recognition and prompt treatment to avoid long-term complications. Parents should seek medical attention if their child has a high fever lasting more than 5 days, especially if other symptoms appear.

Kawasaki Disease and COVID-19

During the COVID-19 pandemic, doctors noticed a condition called Multisystem Inflammatory Syndrome in Children (MIS-C), which shares similarities with Kawasaki Disease. While not identical, both involve systemic inflammation and can affect the heart.

Prognosis

With early treatment, 95% of children recover fully. Long-term outcomes depend on whether coronary artery damage occurred. Children with normal echocardiograms usually lead normal lives without restrictions.

Frequently Asked Questions (FAQs)

1. Is Kawasaki Disease contagious?

No, Kawasaki Disease is not contagious. Children cannot catch it from others.

2. Can adults get Kawasaki Disease?

While extremely rare, Kawasaki Disease can occur in adults, though symptoms and complications may differ.

3. How long does Kawasaki Disease last?

The illness usually lasts 6–8 weeks if untreated, but treatment shortens recovery and reduces complications.

4. Can Kawasaki Disease cause death?

If untreated, complications such as coronary aneurysms can be life-threatening. With timely treatment, deaths are very rare.

5. What is the difference between Kawasaki Disease and MIS-C?

MIS-C (linked to COVID-19) has overlapping features with Kawasaki Disease but also includes shock, severe abdominal pain, and more widespread organ involvement.

6. Will my child need lifelong medication after Kawasaki Disease?

Most children do not need lifelong medication unless they have coronary artery abnormalities. Those with complications may require long-term blood thinners.

Kawasaki Disease is a rare but serious condition that primarily affects young children. The key to good outcomes lies in early recognition and treatment. While the exact cause remains unclear, modern treatment methods like IVIG and aspirin have drastically improved recovery rates and reduced complications.

Parents and caregivers should remain vigilant for symptoms, particularly persistent high fever in young children, and seek immediate medical care. With timely intervention, the vast majority of children with Kawasaki Disease go on to live healthy, normal lives.