Kawasaki Disease

Kawasaki Disease

Definition

• Acute systemic vasculitis primarily affecting children under 5 years

• Leading cause of acquired heart disease in children

• Often follows an upper respiratory tract infection with an unknown exact aetiology

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Diagnostic Criteria

• Fever for ≥5 days plus four of the following five features

  • Bilateral, non-purulent conjunctivitis

  • Polymorphous rash, typically maculopapular and non-vesicular

  • Mucosal changes such as erythema, cracked lips, strawberry tongue

  • Peripheral changes including erythema and oedema of palms/soles, with desquamation in the subacute phase

  • Unilateral cervical lymphadenopathy >1.5 cm in diameter

• Incomplete Kawasaki disease: Fever ≥5 days with 2–3 principal features, supported by laboratory findings (elevated CRP/ESR) and echocardiographic evidence of coronary abnormalities

• Other associated features may include gastrointestinal symptoms, aseptic meningitis, sterile pyuria, uveitis, and gallbladder hydrops

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Differential Diagnosis

• Scarlet fever: Characterised by a sandpaper rash and strawberry tongue

• Staphylococcal scalded skin syndrome: Presents with widespread erythema, flaccid blisters, and skin peeling

• Measles: Features include Koplik spots, rash, and conjunctivitis

• Epstein-Barr virus infection: Associated with fever, lymphadenopathy, and pharyngitis

• Toxic shock syndrome: Rapid onset with shock and diffuse rash

• Systemic juvenile idiopathic arthritis: Persistent fever, salmon-pink rash, and arthritis

• Stevens-Johnson syndrome: Notable for mucosal involvement and skin detachment

• Drug eruptions and acute rheumatic fever

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Management

• Intravenous Immunoglobulin (IVIG)

  • Administer 2 g/kg IV as a single infusion over 10–12 hours, ideally within the first 7 days of illness

  • Reduces the risk of coronary artery aneurysms significantly

• Aspirin

  • High-dose during the acute phase at 30–100 mg/kg/day divided into multiple doses until afebrile for 48 hours

  • Switch to low-dose aspirin (3–5 mg/kg/day) for at least 6 weeks or longer if coronary abnormalities persist

• Corticosteroids

  • Consider for IVIG-resistant cases or high-risk patients

  • Options include methylprednisolone 30 mg/kg IV (maximum 1000 mg) over 1 hour for 1–3 days or oral prednisolone 2 mg/kg/day

• Biologic Agents

  • For severe refractory cases, consider agents such as infliximab under specialist guidance

• Supportive Care

  • Maintain hydration and provide symptomatic management

  • Monitor for signs of cardiac compromise and manage complications accordingly

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Follow-Up

• Serial echocardiography at diagnosis, 2 weeks, and 6–8 weeks post-diagnosis to monitor coronary artery status

• Long-term cardiology follow-up for children with coronary abnormalities, including possible continued aspirin or anticoagulant therapy

• Regular monitoring of inflammatory markers (CRP, ESR) to assess treatment response

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Notes

• Coronary artery aneurysms are the primary complication and early treatment is crucial to mitigate this risk

• Incomplete Kawasaki disease is more common in infants under 1 year and may require additional laboratory and imaging support for diagnosis

• Parental education is essential to manage expectations and stress during the acute phase

• A multidisciplinary approach ensures optimal care and monitoring throughout the disease course