COVID-19–Associated Croup in Children

Abstract

Introduction As SARS-CoV-2 has evolved, so has its effects on the pediatric population.1 While early variants typically resulted in lower respiratory infections, the recently identified Omicron variant may exhibit a predilection for the upper airways.2 The relatively smaller upper respiratory tract in children compared to adults has been thought to predispose them to more severe clinical presentations resembling laryngotracheobronchitis, or croup. Caused by viral-induced subglottic airway inflammation, croup is classically characterized by sudden onset “barking cough”, inspiratory stridor, and respiratory distress. Endemic coronaviruses have been linked to croup, however only sparse case reports have described croup specifically associated with SARS-CoV-2 and it remains unclear if croup cases constitute a causative relationship or result of co-infection with another virus.3–6 To address this knowledge gap, we performed a retrospective analysis of the incidence and clinical characteristics of croup associated with SARS-CoV-2 infection at a large freestanding children’s hospital.

Croup during the Coronavirus Disease 2019 Omicron Variant Surge

“…A similar surge was seen by colleagues on the other side of the country, confirming this observation is more than just local to our practice. 13 This increase was not temporally associated with the circulation of parainfluenza virus, and indeed Omicron replaced parainfluenza as the predominant virus associated with croup during this time. Viral testing is not routinely recommended for patients with croup; testing that was performed was for a wide variety of patients and indications, but we do believe our data is a reasonable proxy for local population prevalence.…”

Croup as a Manifestation of SARS-CoV-2 Omicron Variant Infection in Young Children

“…Two recent studies conducted in Seattle Children’s Hospital and Boston Children’s Hospital observed a marked increase in cases of croup during the omicron surge. 3 10 Tests for COVID-19 were more likely to be positive in children with croup during the omicron wave compared to those during the delta wave. Similarly, our study observed a sudden increase in the proportion of children with COVID-19 hospitalized due to moderate to severe croup in February 2022, when the omicron variant became dominant in South Korea.…”

“…2 Sporadic case reports suggest severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as a pathogen responsible for croup, and many clinicians have observed spikes in croup cases during the current omicron (B.1.1.529) wave. 3 4 5 6 7 8 9 10 Herein, we report a recent sharp rise in pediatric coronavirus disease 2019 (COVID-19) cases requiring hospitalization due to croup during the omicron surge in Seoul, South Korea.…”

“…Meanwhile, the requirement of multiple administration of dexamethasone and nebulized epinephrine observed in our study may imply that croup due to SARS-CoV-2 may be more severe in manifestation compared to other known pathogens. 1 10 …”

“… 13 14 However, previously reported cases and recent studies have demonstrated that SARS-CoV-2 alone could cause croup in children, and the results of our study are valuable to increase the awareness about croup in young children with COVID-19. 4 7 10 16 …”