Pediatric emergency medicine trisk 3002 3002

world. It is more common in winter and early spring in North America. The disease
may be more difficult to diagnose in infants and adolescents, and it is more likely to
cause chronic sequelae in these age groups.
Characteristically, children with KD have fever, conjunctivitis, rash, mucosal
inflammation, lymphadenopathy, and extremity changes. The major morbidity of KD,
however, occurs in the heart. Coronary artery aneurysms (CAA) or ectasia develop in
approximately 15% to 25% of untreated children and may lead to myocardial
infarction, sudden death, arrhythmias, depressed myocardial contractility and heart
failure, and chronic coronary artery insufficiency. IVIG decreases the incidence of
coronary artery aneurysms by three- to fivefold if given within 10 days of disease
onset. A recent prospective study from the Netherlands showed that male gender, delay
of treatment (>10 days), and IVIG retreatment were independent risk factors for
coronary artery aneurysm development. Management of children with suspected KD,
therefore, requires accurate and expeditious diagnosis and close monitoring of the
cardiovascular system.
In KD, as in other forms of vasculitis, blood vessel damage appears to result from an
aberrant immune response leading to endothelial cell injury and vessel wall damage. A
direct cell-mediated attack on endothelial cells, either because they are infected with an
as-yet unidentified infectious agent, or simply as innocent bystanders, may underlie the
vascular injury. The reason that KD preferentially involves coronary arteries is
unknown.
The pathologic changes of the coronary arteries seen in KD have been classified by
Fujiwara and Hamashima into four stages, depending on the duration of illness at the
time of examination ( Table 101.15 ). Many lines of evidence point toward a role of
infections in the causation of KD. The fact that the disease often occurs in epidemics,
that boys are more susceptible than girls, and that household contacts of children with
KD are at increased risk for developing the disease in Japan, all point to a transmissible
agent. Nonetheless, although many putative etiologies have been proposed during the
past four decades, suggestions that certain viruses (EBV, human coronavirus,
parvovirus, HIV-2) or bacterial toxins (streptococcal erythrogenic toxin, staphylococcal
toxic shock toxin) account for the majority of cases have not been substantiated.

Increased incidence in Asian populations suggests a genetic component. Many
researchers now believe that KD represents a final common pathway of immunemediated vascular inflammation in genetically susceptible children triggered by any of
a variety of common infections.