Kawasaki disease

Question 1

Define Kawasai disease.

Answer 1

A type of vasculitis predominantly seen in children. Uncommon but can cause serious complications including coronary artery aneurysms.

Question 2

What age group is most affected by Kawasaki disease?

Answer 2

Children from 6months to 4 years of age (peak at 1st year of life)

More common in Japanese and sometimes Black-Caribbean ethnicity

Question 3

What diagnostic tests are available for Kawasaki disease? What do investigations show?

Answer 3

None - clinical diagnosis alone

High CRP, high ESR, high WCC and plt rise in 2nd week of disease. Coronary arteries are affected within first 6 weeks of illness which can cause aneurysms.

Question 4

What are the clinical features of Kawasaki disease?

Answer 4

CRASH and BURN

• C: conjunctivitis (non-purulent).
• R: rash (non-vesicular).
• A: adenopathy (cervical).
• S: strawberry tongue (and peeling, red lips).
• H: hand and foot erythema and swelling.
• and BURN: >5 days high fever with minimal response to paracetamol.

Young infants are most severely affected and may not have all cardinal symptoms i.e. ‘incomplete’ cases can occur so must maintain high index of suspicion; may have irritability, high fever and inflammation of BCG scar. Irritability does not improve with antipyretics in these children.

Question 5

What should you prescribe to manage Kawasaki disease?

Answer 5

• High dose aspirin - one of few indications for its use in children due to risk of Reye’s syndrome; reduces risk of thrombosis; given until no fever and inflammatory markers return back to normal
• IV Ig - prescribed within first 10 days lowers risk of coronary artery aneurysms.

Low dose aspirin is continued at low dose until echocardiogram at 6 weeks shows no sign of aneurysms.

If fever and inflammation persists despite treatment then give second dose of IV Ig and then consider adding mAb infliximab (against TNF-alpha), corticosteroids or cyclosporin.

Question 6

What screening test should be done for detection of complications of Kawasaki disease?

Answer 6

Echocardiogram to screen for coronary artery aneurysms, pericardial effusion, myocardial disease (poor contractility), endocardial disease (valve regurgitation). MRI may be required if abnormal.

Question 7

What is the mortality rate of Kawasaki disease?

Answer 7

1-2%

Question 8

What are the complications of Kawasaki disease?

Answer 8

• Coronary artery aneurysms
• Sudden death
• Narrowing of vessels from scar formation can lead to myocardial ischaemia and sudden death
• Myocardial disease causing poor contractility
• Endocardial disease causing valve dysfunction

Question 9

This 2-year-old boy developed a high fever of 2 days’ duration. Examination showed a miserable child with mild conjunctivitis, a rash, and cervical lymphadenopathy. A viral infection was diagnosed and his mother was reassured. When he presented to hospital 3 days later, he was noted to have cracked red lips. He was admitted and a full septic screen, including a lumbar puncture, was performed and antibiotics started. The following day, he was still febrile and irritable; his C-reactive protein and erythrocyte sedimentation rate were raised considerably above upper limit of normal.

What is the management?

Answer 9

Kawasaki disease was suspected and he was treated with intravenous immunoglobulin and high-dose oral aspirin. His clinical condition improved and he became afebrile the following morning. An echocardiogram at this stage showed no aneurysms of the coronary arteries, which are the most serious complication associated with delayed diagnosis and treatment. On the 15th day of the illness there was peeling of the fingers and toes.

Question 10