Overview
Kawasaki disease is an idiopathic self-limiting vasculitis predominantly seen in children in the age range of 6 months to 5 years.
Early diagnosis and treatment are crucial to prevent complications such as coronary artery aneurysms from arising. Around ¼ of untreated patients develop coronary artery aneurysms.
It was first described in 1967 by Tomisaku Kawasaki, a Japanese paediatrician.
Epidemiology
- Usually seen in children from 6 months of age to 5 years
- More common in boys
- More commonly seen in East Asian children
Risk Factors & Associations
- Asian ancestry
- Age 6 months to 5 years
- Male sex
Classical History
A 1-year-old girl was admitted to the hospital with a 7-day fever of 39.5°C. On examination, it is noted she has bilateral conjunctivitis, erythema of the palms of the hands and soles of the feet, and cervical lymphadenopathy.
Presentation
Children are usually very irritable
- Fever lasting ≥5 days
- Redness, swelling, and desquamation of the skin on the palms and soles
- Bilateral conjunctivitis without exudate
- Rash
- Inflammation of the lips, mouth and/or tongue
- This can present as bright red and cracked lips
- A strawberry tongue may be seen
- Cervical lymphadenopathy
Differential Diagnoses
Scarlet fever
- Presents very similarly to Kawasaki disease
- Sore throat present
- The lips are spared
- There’s no conjunctivitis
- Signs of an upper respiratory tract infection may be present
- Positive serology for group A streptococcus
Acute rheumatic fever
- 3-4 weeks following group A streptococcal infection
- Migratory polyarthritis may be present
- Erythema marginatum may be seen
- Chorea may be seen
Staphylococcal scalded skin syndrome
- Nikolsky sign positive – epidermis slips away with gentle force
- Erythroderma with blisters and erosions
Stevens-Johnson syndrome
- Severe and bullous erythema multiforme
- Diffuse bullae with mucosal involvement
Measles
- Conjunctivitis in measles is usually exudative
- Koplik’s spots may be seen in the mouth
- The rash usually starts behind the ears
Bacterial infection
- Positive response to antibiotics
- Visible skin lesions
- Signs of pneumonia or septic arthritis
- Positive blood culture, throat swab, or skin swab
Investigations
Kawasaki disease is a clinical diagnosis and there is no specific diagnostic test.
- C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR):
- Non-specific markers of inflammation, may be raised
- Echocardiogram:
- An echocardiogram is used in all patients with Kawasaki disease as the initial screening test for coronary artery aneurysms
Management
- 1st line: high-dose aspirin and intravenous immunoglobulin (IVIG)
- This is one of the few indications for aspirin use in children
- Aspirin is normally contraindicated in children due to the risk of Reye’s syndrome
- An echocardiogram is performed after to assess for any coronary artery aneurysm
Monitoring
- Patients are followed up with an echocardiogram to assess for coronary artery aneurysms
- If they are present, patients should be referred to cardiology
- Patients who have been found to have coronary artery aneurysms should be screened for lipid disorders and development of hypertension from age 2 onwards
Patient Advice
- Patients should be advised that children who develop coronary artery aneurysms will need long-term follow-up and screening for lipid disorders and the development of hypertension
Complications
- Sudden cardiac death
- Myocardial infarction
- Coronary artery aneurysm and possible subsequent rupture
- Pericarditis
- Myocarditis
- Arrhythmias
- Heart failure
- Valvular disease
- Acute arthritis
- Dehydration during the feverish period of the illness
Prognosis
- Depends on the degree of cardiac involvement
- Most coronary artery aneurysms regress after 1-2 years but giant aneurysms do not resolve entirely and have a worse prognosis
- Follow-up in later life is recommended as long-term cardiac implications of Kawasaki disease are not yet known
