What are the symptoms and treatment of Kawasaki disease?

Kawasaki Disease: Symptoms and Treatment

Kawasaki disease is diagnosed by the presence of fever lasting at least 5 days plus 4 out of 5 principal clinical features, and treatment consists of intravenous immunoglobulin (IVIG) 2 g/kg as a single infusion along with high-dose aspirin (80-100 mg/kg/day divided into four doses). 1

Diagnostic Criteria

Principal Clinical Features

1. Fever

   • Typically high-spiking (>39°C/102.2°F)
   • Persists for at least 5 days without treatment
   • Usually remittent pattern 1

2. Changes in the Oral Cavity

   • Erythema and cracking of lips
   • Strawberry tongue
   • Diffuse erythema of oral and pharyngeal mucosa
   • No focal lesions, ulcerations, or exudates 1

3. Bilateral Bulbar Conjunctival Injection

   • Non-purulent/non-exudative
   • Often spares the limbus (avascular zone around iris)
   • Photophobia and eye pain typically absent 1

4. Polymorphous Rash

   • Usually appears within first 5 days of illness
   • Primarily truncal with accentuation in the groin
   • Most commonly maculopapular
   • May appear urticarial, scarlatiniform, or erythema multiforme-like
   • Bullous and vesicular lesions are NOT consistent with Kawasaki disease 1

5. Changes in Extremities

   • Acute phase: Erythema and edema of hands and feet
   • Sharp demarcation at ankles and wrists
   • Swelling may be painful
   • Convalescent phase: Periungual desquamation (peeling) starting 2-3 weeks after onset 1

6. Cervical Lymphadenopathy

   • Least common of the principal features
   • Usually unilateral
   • ≥1.5 cm in diameter
   • Confined to anterior cervical triangle 1

Other Clinical and Laboratory Findings

• Cardiovascular: Gallop rhythm, distant heart sounds, ECG changes, cardiomegaly, pericardial effusion 1
• Gastrointestinal: Diarrhea, vomiting, abdominal pain, hydrops of gallbladder, mild jaundice 1
• Laboratory: Elevated ESR and CRP, leukocytosis with left shift, hypoalbuminemia, mild anemia, thrombocytosis (in second week) 1

Treatment Algorithm

Initial Treatment

1. IVIG: 2 g/kg as a single infusion (Level A evidence) 1

   • Should be administered within 10 days of illness onset
   • Reduces risk of coronary artery aneurysms from 20-25% to <5%

2. Aspirin: High-dose (80-100 mg/kg/day divided into four doses) during acute phase (Level C evidence) 1

   • Continue until patient is afebrile for 48-72 hours
   • Then reduce to low-dose (3-5 mg/kg/day) for antiplatelet effect
   • Continue low-dose aspirin for 6-8 weeks if no coronary abnormalities

For IVIG-Resistant Cases

• Second IVIG dose: 2 g/kg if fever persists or recurs within 36 hours after initial IVIG completion 1
• Consider adjunctive therapies:
  • Corticosteroids
  • TNF-α antagonists
  • Other immunomodulatory agents 1

Important Considerations

• Incomplete/Atypical Kawasaki: Fever ≥5 days with 2-3 principal features; requires additional laboratory criteria and echocardiography 1

• Differential Diagnosis: Consider measles, scarlet fever, toxic shock syndrome, drug reactions, and bacterial lymphadenitis 1

• Pitfalls to Avoid:

  1. Delaying treatment while waiting for all clinical features to appear (features may not be present simultaneously) 1
  2. Missing the diagnosis in patients with predominant lymphadenopathy, which can mimic bacterial lymphadenitis 2
  3. Failing to consider Kawasaki disease in patients with unusual presentations (e.g., inguinal cellulitis) 3
  4. Overlooking the diagnosis in older children or adults (rare but occurs) 4

• Long-term Management: Based on degree of coronary involvement; may require ongoing antiplatelet therapy, activity restrictions, and cardiac monitoring 1

Remember that early diagnosis and prompt treatment are crucial to reduce the risk of coronary artery abnormalities, which develop in 15-25% of untreated children and can lead to myocardial infarction, sudden death, or ischemic heart disease 5.