Pediatrics · Year 3 · from Pediatrics

Case 1: Kawasaki Disease

Patient Demographics

  • Age: 3-year-old male
  • Sex: Male

Chief Complaint

"He's had a high fever for 5 days that won't go away."

History of Present Illness

A 3-year-old previously healthy male presents with 5 days of persistent high fever (39.5-40.5C) despite alternating acetaminophen and ibuprofen. Mother reports he developed a rash on day 2 of illness that began on the trunk and spread to extremities. His eyes became red and "bloodshot" without discharge on day 3. He has been extremely irritable and refusing to eat. Parents noted his lips became cracked and red, and his tongue looked "bumpy." Today they noticed swelling of his hands and feet. He was seen at urgent care on day 3 and started on amoxicillin for presumed strep throat, but the fever has continued. No respiratory symptoms, vomiting, or diarrhea.

Growth Parameters

  • Height: 97 cm (60th percentile)
  • Weight: 15 kg (55th percentile)

Physical Examination

  • General: Ill-appearing, irritable child, inconsolable
  • Vital signs: T 40.1C, HR 140, RR 28, BP 95/60
  • HEENT:
  • Bilateral bulbar conjunctival injection without exudate
  • Erythematous, dry, cracked lips
  • "Strawberry tongue" - erythematous tongue with prominent papillae
  • Oropharyngeal erythema
  • Unilateral cervical lymphadenopathy (2.5 cm, mobile, tender)
  • Cardiovascular: Tachycardia, no murmur, bounding pulses
  • Respiratory: Clear breath sounds
  • Abdomen: Soft, mildly tender, no hepatosplenomegaly
  • Extremities: Erythema and edema of hands and feet, induration of palms and soles
  • Skin: Polymorphous maculopapular rash over trunk and extremities, no vesicles
  • Neurologic: Irritable but alert

Workup

  • CBC: WBC 18,500 (80% neutrophils), Hgb 10.8, Platelets 420,000
  • CMP: Na 132, otherwise normal
  • ESR: 85 mm/hr (elevated)
  • CRP: 14.2 mg/dL (elevated)
  • Urinalysis: Sterile pyuria (25 WBC/hpf, negative culture)
  • AST/ALT: 68/72 U/L (mildly elevated)
  • Albumin: 2.8 g/dL (low)
  • Echocardiogram: Mild dilation of proximal left coronary artery (LAD z-score +2.7), normal RCA, no pericardial effusion

Diagnosis

Kawasaki disease with coronary artery involvement

Clinical Reasoning

This child meets classic diagnostic criteria for Kawasaki disease with >=5 days of fever plus 4 of 5 principal features: (1) bilateral conjunctival injection, (2) oral mucosal changes (cracked lips, strawberry tongue), (3) extremity changes (edema/erythema), (4) polymorphous rash, and (5) cervical lymphadenopathy >1.5 cm. Supporting laboratory findings include elevated inflammatory markers, sterile pyuria, thrombocytosis (or normal early in disease), and hypoalbuminemia. The echocardiogram showing coronary artery dilation (z-score >2.5) confirms cardiac involvement, making prompt treatment essential.

Management

  1. IVIG: 2 g/kg IV as single infusion over 10-12 hours
  2. High-dose aspirin: 80-100 mg/kg/day divided q6h until afebrile for 48-72 hours
  3. Then low-dose aspirin: 3-5 mg/kg/day (antiplatelet) for 6-8 weeks minimum
  4. If IVIG-refractory (fever >36 hours after IVIG):
  • Second dose of IVIG 2 g/kg, OR
  • IV methylprednisolone
  • Consider infliximab for refractory cases
  1. Cardiac monitoring:
  • Repeat echocardiogram at 2 weeks and 6-8 weeks
  • If coronary abnormalities persist, long-term cardiology follow-up
  • If coronary aneurysms develop, anticoagulation may be needed
  1. Avoid live vaccines for 11 months after IVIG (MMR, varicella)

Clinical Image

Image Description: Clinical photograph composite demonstrating classic features of Kawasaki disease including conjunctival injection, strawberry tongue, and erythematous cracked lips.

Source: Wikimedia Commons URL: https://commons.wikimedia.org/wiki/File:Kawasaki_symptoms_A.png License: CC BY 3.0

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