Croup may be a new presentation of the Omicron SARS-CoV-2 variant in children, according to preliminary findings from a study at the Boston Children’s Hospital in the United States. Some of these children may require hospitalization including ICU admission.

The study reported in the journal Pediatrics retrospectively analysed 75 Covid-positive children who visited the emergency department of Boston Childrens Hospital with Covid-19 between March 1, 2020 and January 15, 2022. Those with laryngotracheitis during the same hospital visit were included in the present study. Slightly over 80% of these children were diagnosed during the Omicron wave. Most of them were under two years of age and 72% were male. Only one child had a rhinovirus infection other than SARS-CoV-2, rest were negative for other viruses tested such as adenovirus, influenza, parainfluenza, human metapneumovirus (HMPV) and respiratory syncytial virus (RSV).

There was no mortality, but nine children (12%) were hospitalized and four of them were admitted to ICU. The median duration of hospitalization was nearly 2 days. No child required invasive ventilation. All hospitalized children received racemic epinephrine through nebulizer, but only a quarter of them were administered the medication in the emergency department. Almost all children (97%) received dexamethasone. A median number of eight doses of epinephrine and six doses of dexamethasone were required in hospitalized children for symptom control.

This single-center study documents an increase in croup cases concurrent with the advent of the Omicron variant and suggests that the virus may cause laryngotracheobronchitis, commonly called croup. “The high hospitalization rate and the large number of medication doses required by the patients suggest that COVID-19 might cause more severe croup compared to other viruses”. This can be attributed to the predilection of the Omicron variant to the upper respiratory tract rather than the lower respiratory tract. Since children younger than 5 years are not yet eligible for Covid vaccine, there should be a high index of suspicion for Covid-19 in children with croup.

Reference

1. Brewster RCL, et al. COVID-19-associated croup in children. Pediatrics. 2022 Mar 8. doi: 10.1542/peds.2022-056492.