From the Guidelines
Incomplete Kawasaki disease should be considered in all children with unexplained fever for 5 days associated with 2 or 3 of the principal clinical features of Kawasaki disease, and treatment should be initiated promptly with intravenous immunoglobulin (IVIG) and high-dose aspirin to reduce the risk of coronary artery aneurysms. Diagnosis of incomplete Kawasaki disease can be challenging, especially in young infants who may present with fever and few, if any, principal clinical features 1. Laboratory findings supporting the diagnosis include elevated inflammatory markers, anemia, hypoalbuminemia, elevated liver enzymes, thrombocytosis after day 7, sterile pyuria, and elevated NT-proBNP. Echocardiography may also be useful in evaluating children with protracted fever and some features of Kawasaki disease, as it can detect coronary arteritis before the formation of aneurysms 1.
Some key points to consider in the diagnosis and treatment of incomplete Kawasaki disease include:
- Incomplete Kawasaki disease is more common in young infants than in older children, making accurate diagnosis and timely treatment especially important in these young patients who are at substantial risk of developing coronary abnormalities 1
- Treatment should be initiated promptly with IVIG at 2 g/kg as a single infusion over 10-12 hours, along with high-dose aspirin (80-100 mg/kg/day divided into 4 doses) during the acute phase until the patient is afebrile for 48-72 hours
- After fever resolution, aspirin is reduced to an antiplatelet dose (3-5 mg/kg/day once daily) for 6-8 weeks or longer if coronary abnormalities develop
- For IVIG-resistant cases (persistent or recurrent fever 36 hours after completion of IVIG), a second IVIG dose should be considered, or alternative therapies such as corticosteroids, infliximab, or cyclosporine may be used 1
- Cardiac echocardiography should be performed at diagnosis, 1-2 weeks, and 4-6 weeks after treatment to monitor for coronary artery aneurysms, which are the most serious complication of Kawasaki disease.
From the Research
Diagnosis of Incomplete Kawasaki Disease
- Incomplete Kawasaki disease is diagnosed based on the presence of a fever lasting five or more days and two or three of the following findings: bilateral conjunctival injection, oral changes, cervical lymphadenopathy, extremity changes, and polymorphous rash 2.
- The diagnosis of incomplete Kawasaki disease is challenging and requires a high index of suspicion 3.
- Clinical and laboratory features, such as changes in the extremities, conjunctival injection, exanthem, and enanthem, are less common in incomplete Kawasaki disease compared to complete Kawasaki disease 4.
Epidemiology of Incomplete Kawasaki Disease
- Incomplete Kawasaki disease accounts for approximately 20% of all Kawasaki disease cases 5.
- The prevalence of coronary artery lesions (CALs) is lower in incomplete Kawasaki disease compared to complete Kawasaki disease (4.5% vs 42.2%) 5.
- Children with incomplete Kawasaki disease may be at lower risk for the development of CALs compared to those with complete Kawasaki disease 5.
Treatment of Incomplete Kawasaki Disease
- The primary treatment for incomplete Kawasaki disease is intravenous immunoglobulin (IVIG) and aspirin 2.
- High-dose IVIG regimens are probably associated with a reduced risk of coronary artery abnormality formation compared to medium- or low-dose IVIG regimens 6.
- The evidence comparing IVIG with prednisolone on incidence of coronary artery abnormality is very uncertain 6.
Age Distribution of Incomplete Kawasaki Disease
- Kawasaki disease, including incomplete Kawasaki disease, predominantly affects patients younger than five years 2.
- The mean age of patients with incomplete Kawasaki disease is around 33 months 4.
- Incomplete Kawasaki disease can occur in children of any age, but it is more common in younger children 5.