Seven days of fever, cracked lips, and a normal echocardiogram: treating Kawasaki disease without delay
An 18-month-old girl has had 7 days of fever to 40°C, bilateral nonexudative conjunctivitis, cracked red lips, a strawberry tongue, a polymorphous rash, and swollen hands. Her BCG scar is red. Echocardiography on day 7 shows no coronary artery dilation. CRP is 210 mg/L, platelets 520,000/µL, albumin 26 g/L, ALT 95 U/L, and WBC 18,000/µL. She has been treated with antipyretics alone and sent home twice as a "viral illness."
1. What is the diagnosis and immediate management, and why does a normal echocardiogram not change it?
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This is Kawasaki disease-fever for at least 5 days plus conjunctivitis, mucosal changes, rash, and extremity changes, with supportive labs (high CRP, thrombocytosis, hypoalbuminemia, transaminitis). BCG scar erythema is a recognized feature. The diagnosis is clinical; a normal echocardiogram on day 7 does not exclude it, because coronary dilation often appears later and treatment prevents it.
Give IVIG 2 g/kg over 10–12 hours and aspirin (moderate- to high-dose, 30–50 or 80–100 mg/kg/day divided, per local protocol) until afebrile for 48 hours, then low-dose aspirin. Admit for monitoring. Repeat echocardiography at 1–2 weeks and 6–8 weeks. Delay is the main risk factor for coronary artery aneurysms.
2. Thirty-six hours after IVIG she is still febrile. What are the options, and how do you choose?
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Persistent fever 36 hours after completing IVIG defines IVIG resistance and warrants escalation. Options are a second IVIG 2 g/kg, IV methylprednisolone (e.g., 30 mg/kg) followed by prednisolone, or infliximab; guidelines support corticosteroids, especially in higher-risk patients. Risk scores (low albumin, high CRP, young age, thrombocytosis, transaminitis) suggest she is at higher risk of resistance and coronary involvement.
Re-examine for alternative or coexisting infection, since persistent fever is not automatically Kawasaki. Repeat echocardiography. Do not simply observe or switch to oral antibiotics. Document coronary status at each step and involve pediatric cardiology early if dilation appears.
3. At discharge the parents ask about vaccinations and follow-up. What do you advise?
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High-dose IVIG contains passive antibodies, so MMR and varicella vaccines should be deferred for 11 months; inactivated vaccines can be given on schedule. Advise avoiding salicylate-containing products and varicella exposure while on aspirin, given Reye syndrome risk. Provide a clear cardiology follow-up plan: echocardiography at 1–2 weeks and again at 6–8 weeks, with longer follow-up and aspirin if any coronary change is found.
Teach the family the red flags for recurrence or coronary complications (fever, chest pain, lethargy) and explain that Kawasaki is not contagious. Reinforce that she remains at risk for coronary sequelae even if she looks well, and document the vaccine deferral so it is not missed at the primary care visit.