Kawasaki Disease

Question 1

What is Kawasaki disease?
Epidemiology?

Answer 1

Kawasaki disease is also known as mucocutaneous lymph node syndrome. It is a systemic, medium-sized vessel vasculitis. It affects young children, typically under 5 years. There is no clear cause or trigger. It is more common in Asian children, particularly Japanese and Korean children. It is also more common in boys.

Question 2

Key complication Kawasaki disease?

Answer 2

A key complication is coronary artery aneurysm.

Question 3

Clinical features Kawasaki disease?

Answer 3

A key feature that should make you consider Kawasaki disease is a persistent high fever (above 39ºC) for more than 5 days. Children will be unhappy and unwell. The key skin findings are a widespread erythematous maculopapular rash and desquamation (skin peeling) on the palms and soles.

Other features include:

Strawberry tongue (red tongue with large papillae)
Cracked lips
Cervical lymphadenopathy
Bilateral conjunctivitis

TOM TIP: If you come across a child with a fever persisting for more than 5 days, think of Kawasaki disease! A rash, strawberry tongue, lymphadenopathy and conjunctivitis will seal the diagnosis in your exams.

Question 4

Investigations Kawasaki disease?

Answer 4

There are several investigations that can be helpful in Kawasaki disease:

Full blood count can show anaemia, leukocytosis and thrombocytosis
Liver function tests can show hypoalbuminemia and elevated liver enzymes
Inflammatory markers (particularly ESR) are raised
Urinalysis can show raised white blood cells without infection
Echocardiogram can demonstrate coronary artery pathology

Question 5

Disease course Kawasaki disease?

Answer 5

There are three phases to Kawasaki disease:

Acute phase: The child is most unwell with the fever, rash and lymphadenopathy. This lasts 1 – 2 weeks.
Subacute phase: The acute symptoms settle, the desquamation and arthralgia occur and there is a risk of coronary artery aneurysms forming. This lasts 2 – 4 weeks.
Convalescent stage: The remaining symptoms settle, the blood tests slowly return to normal and the coronary aneurysms may regress. This last 2 – 4 weeks.

Question 6

Management Kawasaki disease?

Answer 6

There are two first line medical treatments given to patients with Kawasaki disease:

High dose aspirin to reduce the risk of thrombosis
IV immunoglobulins to reduce the risk of coronary artery aneurysms

Patients will need close follow up with echocardiograms to monitor for evidence of coronary artery aneurysms.

TOM TIP: Kawasaki disease is one of the few scenarios where aspirin is used in children. Aspirin is usually avoided due to the risk of Reye’s syndrome. This is a unique fact that examiners like to test.