Kawasaki disease
USMLE Step 2 CKDifficulty: easyLast updated:
A 3-year-old boy is brought to the clinic because of 6 days of fever up to 39.8°C (103.6°F) that has not responded to antipyretics. Examination shows bilateral nonexudative bulbar conjunctival injection, red cracked lips with a strawberry tongue, a polymorphous truncal rash, edema of the hands and feet, and a 2-cm unilateral cervical lymph node. A rapid streptococcal test is negative. ESR and CRP are elevated. Echocardiography is scheduled.
Which of the following is the most appropriate treatment?
Answer and explanation
Correct answer: B. Intravenous immune globulin 2 g/kg plus high-dose oral aspirin
At least 5 days of fever with bilateral nonexudative conjunctival injection, oral mucosal changes, rash, extremity changes, and cervical lymphadenopathy fulfill the clinical criteria for Kawasaki disease. This is a vasculitis of medium-sized arteries that involves the coronary arteries in about 25% of untreated patients. The source states that therapy should start as soon as possible, optimally within the first 10 days of illness, with IVIG as a single 2 g/kg dose over 10 to 12 hours plus high-dose oral aspirin (80–100 mg/kg/day in the US; Japan and Western Europe use moderate doses of 30–50 mg/kg/day, with similar aneurysm rates). The aspirin dose is reduced after the child has been afebrile for several days. Serial ECG and echocardiography with cardiology follow-up are needed because coronary artery aneurysms can rupture or thrombose.
Each option explained
- A. Intravenous ceftriaxone plus vancomycinIncorrect. This child has no evidence of bacterial sepsis or meningitis; antibiotics do not treat Kawasaki vasculitis.
- B. Intravenous immune globulin 2 g/kg plus high-dose oral aspirinCorrect. IVIG (2 g/kg single dose) with high-dose (or moderate-dose) aspirin, ideally within 10 days of illness onset, reduces coronary complications.
- C. Oral amoxicillin for 10 daysIncorrect. Amoxicillin treats streptococcal pharyngitis or scarlet fever; the rapid strep test is negative and the features fit Kawasaki disease.
- D. Oral prednisolone aloneIncorrect. Corticosteroids are not the standard initial monotherapy; IVIG plus aspirin is first-line.
- E. Ibuprofen and supportive care until the fever resolvesIncorrect. Supportive care alone misses the window to prevent coronary artery aneurysms.
Key point
Kawasaki disease: give IVIG 2 g/kg plus high-dose aspirin, optimally within 10 days of fever onset, and follow with echocardiography.
From the source
“Therapy is started as soon as possible, optimally within the first 10 days of illness, with a combination of IVIG (single dose of 2 g/kg given over 10 to 12 hours) and oral high-dose aspirin”