key: cord-1020006-bpn5clm9
authors: Choi, Jong-Woon
title: Can we get a clue for the etiology of Kawasaki disease in the COVID-19 pandemic?
date: 2020-07-13
journal: Clin Exp Pediatr
DOI: 10.3345/cep.2020.00955
sha: 62c49b0938f218cd00c5361ade6ee2434f158f4b
doc_id: 1020006
cord_uid: bpn5clm9

nan

in western countries. Despite many clinical and experimental studies spanning decades, the etiology of KD remains unknown. However, its pathogenesis is explained by the theory of abnormal or dysregulated immune reactions. It has been postulated that one of pathogens (including viruses, bacteria, etc.), toxins, or environmental agents may trigger abnormal or dysregulated immune reactions in genetically susceptible children, leading to release of large amounts of proinflammatory cytokines, and causes KD manifesting systemic vasculitis. 3) So KD can be included within the spectrum of the cytokine storm syndrome. The reason why the etiology of KD has not been found out may be because the triggering or causative factor of KD may be not only one agent, but be multiple agents.

The KD-like illness related with COVID-19 was reported to develop 2-4 weeks after the peak of the COVID-19 pandemic in Europe and the US. This may be consistent with the fact that the incidence of KD shows annual and seasonal variations. Nationwide surveys in Korea and Japan and epidemiological studies in the US indicated that the incidence of KD peaks in the winter and early summer. 3, 4) This is consistent with the observation that KD seems to be associated with antecedent res piratory illnesses and develop after epidemic periods of viral illnesses. 3, 5) On the contrary, the age distribution of patients with the KD-like illness related with COVID-19 differs from that of KD patients. KD usually develops in infants and younger children, and is uncommon in older children more than 10 years of age; approximately 80% of KD patients are less than 5 years of age and about half are less than 2 years of age. 3, 4) However, the KDlike illness related with COVID-19 usually developed after 1-2 years of age and was also common in children older than 10 years of age. 1, 2) The incidence rate of KD is the highest in east Asian countries, and relatively low in western countries, which may reflect differences in races or environments. In contrast, the KD-like illness related with COVID-19 was most commonly reported in Europe and the US, and rarely reported in east Asian countries, although the incidence of COVID-19 was also high in east Asian countries. This might be due to the difference in

Clinical characteristics of 58 children with a pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2

Acute heart failure in multisystem inflammatory syndrome in children (MIS-C) in the context of global SARS-CoV-2 pandemic

Diagnosis, treatment, and long-term management of Kawasaki disease: a scientific statement for health professionals from the American Heart Association

Epidemiological and clinical features of Kawasaki disease in South Korea

We have not experienced a pandemic disease like COVID-19 until now. COVID-19 has spread globally in a short period of time, resulting in many cases in every country. Many people have undergone diagnostic testings, which has revealed its detailed epidemiological and clinical features. In addition, a KDlike illness occurred in children that seemed to be related with COVID-19. The occurrence of such cases may provide the opportunity for us to learn more about the etiology and pathogenesis of KD

The author declares no potential conflict of interest relevant to this article.