Clinical features of croups caused by severe acute respiratory syndrome coronavirus 2 and by other respiratory viruses: analysis in a tertiary hospital in Jinju, Korea during the period of dominance of the Omicron variant (B.1.1.529)

Abstract

Purpose: Croup is a clinical manifestation of coronavirus disease 2019 (COVID-19) in children. The Omicron variant of severe acute respiratory syndrome coronavirus 2 usually causes an upper respiratory tract infection. We investigated the differences between croups caused by COVID-19 and by other respiratory viruses (ORV).Methods: We reviewed clinical characteristics, therapeutic measures, and the Westley Croup Score of children with croup who visited the emergency department of Gyeongsang National University Hospital from January 1 through April 7, 2022. According to the laboratory-confirmed viruses, they were divided into 2 groups: COVID-19 and ORV. Between the 2 groups, we compared the abovementioned features. Moderate-to-severe croup was defined by a Westley Croup Score of 3 or higher. Results: A total of 20 children were diagnosed with croup caused by COVID-19 (n = 11; median age, 18 months) or by ORV (n = 9; 7 months). Median Westley Croup Score was higher in the COVID-19 group than in the ORV group (5.0 [range, 0-10.0] vs. 2.0 [1.0-5.0]; P = 0.031). Among the components of the scoring system, only stridor showed a significant difference (e.g., “stridor at rest”: COVID-19, 8 of 11 vs. ORV, 2 of 9; P = 0.046). Median C-reactive protein concentration was higher in the COVID-19 group (3.2 vs. 0.4 mg/L; P = 0.007). Severity of the COVID-19 group was marginally higher than that of the ORV group in terms of the median oxygen saturation (95% vs. 98%; P = 0.056) and the proportions of moderate-to-severe croup (9 of 11 vs. 3 of 9; P = 0.065) and application of high-flow nasal cannula (4 of 11 vs. 0 of 9; P = 0.094).Conclusion: Croup caused by COVID-19 during the period of dominance of the Omicron variant outbreak might be more severe than croup caused by ORV.