What are the symptoms and treatment of Kawasaki disease?

Kawasaki Disease: Symptoms and Treatment

Kawasaki disease is characterized by fever lasting at least 5 days plus 4 of 5 principal clinical features: bilateral non-exudative conjunctival injection, oral mucosal changes, polymorphous rash, extremity changes, and cervical lymphadenopathy, with treatment consisting of intravenous immunoglobulin (IVIG) and aspirin to prevent coronary artery complications. 1, 2

Principal Diagnostic Criteria

• Fever: Typically high (>102.2°F/39°C, often >104°F/40°C) and persists for at least 5 days if untreated, averaging 11 days without treatment 2
• Bilateral bulbar conjunctival injection: Non-exudative, without limbus involvement, photophobia or eye pain 2
• Changes in lips and oral mucosa: Erythema and cracking of lips, strawberry tongue, diffuse oral and pharyngeal redness 1, 2
• Polymorphous exanthem/rash: Various forms including maculopapular, diffuse erythroderma, or erythema multiforme-like 1, 2
• Extremity changes: Acute phase - erythema and edema of hands and feet; subacute phase - periungual desquamation beginning 2-3 weeks after fever onset 1, 2
• Cervical lymphadenopathy: Usually unilateral, ≥1.5 cm diameter, confined to anterior cervical triangle 1, 2

Additional Clinical Manifestations

• Cardiovascular: Myocarditis, pericarditis, valvulitis, coronary artery aneurysms (15-25% of untreated cases) 2
• Gastrointestinal: Diarrhea, vomiting, abdominal pain, hepatitis, jaundice, gallbladder hydrops, pancreatitis 1, 2
• Musculoskeletal: Arthritis, arthralgia with synovial fluid pleocytosis 1
• Neurological: Irritability, aseptic meningitis 2
• Urinary: Sterile pyuria 2

Laboratory Findings

• Elevated inflammatory markers (CRP, ESR) 3
• Leukocytosis with neutrophil predominance 1
• Thrombocytosis (typically in second week after fever onset) 1
• Low serum sodium and albumin levels 1
• Elevated liver enzymes 1

Treatment Protocol

Initial Treatment

• IVIG: Administer 2 g/kg as a single infusion within 10 days of fever onset 4
• Aspirin: Begin with high-dose (80-100 mg/kg/day divided into four doses) until patient is afebrile for at least 48 hours 4
• Transition to low-dose aspirin: After fever resolution, switch to 3-5 mg/kg/day as a single daily dose 4

Management of IVIG-Resistant Disease (10-20% of cases)

• Consider second dose of IVIG (2 g/kg) for persistent or recrudescent fever at least 36 hours after initial IVIG infusion 4
• Alternative options include infliximab or corticosteroids 4

Long-term Management Based on Coronary Involvement

• No coronary abnormalities: Low-dose aspirin for 6-8 weeks 4
• Small coronary aneurysms: Long-term low-dose aspirin indefinitely 4
• Moderate-sized aneurysms (4-6 mm): Aspirin plus a second antiplatelet agent 4
• Giant aneurysms (≥8 mm): Low-dose aspirin plus warfarin (target INR 2.0-3.0) or aspirin plus therapeutic doses of low-molecular-weight heparin 4

Important Clinical Considerations

• Incomplete Kawasaki disease: Can be diagnosed with fewer criteria if coronary artery abnormalities are present on echocardiography 3
• High-risk groups: Infants <6 months and children >5 years often have delayed diagnosis and higher risk of coronary complications 3
• Timing of treatment: Delaying treatment beyond 10 days of fever onset significantly increases risk of coronary artery abnormalities 4
• Vaccination considerations: Measles and varicella immunizations should be deferred for 11 months after high-dose IVIG administration 4
• Influenza vaccination: Annual influenza vaccination is recommended for children on long-term aspirin therapy 4

Monitoring

• Frequent echocardiography and ECG evaluation during the first 3 months after diagnosis, especially for patients with coronary aneurysms 4
• Highest risk for coronary artery thrombosis occurs within the first 3 months, with peak incidence in the first 15-45 days 4

Differential Diagnosis

• Viral infections (measles, adenovirus) 1
• Bacterial infections (scarlet fever, staphylococcal scalded skin syndrome) 3
• Other conditions with similar features should be considered, particularly those with exudative conjunctivitis, exudative pharyngitis, oral ulcerations, splenomegaly, and vesiculobullous or petechial rashes 1