1 INTRODUCTION
The coronavirus disease 2019 (COVID-19) has led to a global pandemic
with significant morbidity and mortality.1 The
pediatric population appears to be affected in a much smaller number
than adults, with only 1.7% of cases in the United States occurring in
children younger than 18. In other European countries, the number of
cases in children is less than 2%.2-4 Currently, it
is unclear whether this is due to lower infection susceptibility in
children or if the asymptomatic disease is much more common in those
under the age of 18.5; 6
Significant numbers of children and teenagers, tested positive for
COVID-19 antibodies, have developed a severe inflammatory condition with
many disease characteristics of Kawasaki syndrome.7 As
case reports pile up, the world is suddenly paying attention to this
pediatric condition that may be related to COVID-19.8Kawasaki disease is a rare acute pediatric vasculitis, usually involves
small to medium-sized arteries in a wide array of organs and tissues,
and can cause coronary artery aneurysms, myocardial infarction, and
pericarditis.9 It is characterized by fever,
exanthema, lymphadenopathy, conjunctival injection, and changes to the
mucosa and extremities. Kawasaki disease is relatively uncommon, with an
incidence rate of 20.8 per 100,000 in the United States, mainly in
children aged five years or younger.10 The etiology of
this syndrome remains unknown; however, antigen-driven delayed immune
reaction following viral or bacterial infection in genetically
susceptible individuals is the current leading
hypothesis.9 In the last two decades, the coronavirus
family has been proposed to be one of the triggers of Kawasaki syndrome.
Human New Haven coronavirus (HCoV-NH) was identified in the respiratory
secretions of 72.7% of children with Kawasaki
disease11, and positive CoV-229E antibodies was
detected by immunofluorescence assay in patients with Kawasaki
disease12, eliciting a putative link with COVID-19
disease.
Verdoni et al. described an outbreak of a Kawasaki-like disease
occurring in Bergamo, Italy, at the peak of the COVID-19
pandemic.13 As of May 21, other confirmed and
suspected children of similar presentations have been reported
throughout the United States.14 This Kawasaki-like
disease appears to cause a hyperinflammatory shock state. Hypotension
with a requirement for fluid resuscitation seems to be common15. Some patients required inotropic support. Also,
patients with this syndrome appear to respond well to intravenous
immunoglobulin. However, the disease course seems more severe than the
typical Kawasaki’s disease as adjunct anti-inflammatory treatments were
necessary for several patients, with some requiring high-dose
corticosteroids. The use of biologics such as infliximab has also been
described.13; 16
Despite these findings, much remains unknown about this rare
Kawasaki-like disease. Some children have needed intensive care unit
(ICU), others recovered quickly. The goal of this meta-analysis was to
summarize the clinical and laboratory features of patients with
Kawasaki-like disease diagnosed during the COVID-19 pandemic.