‘Compelling evidence’ links SARS-CoV-2 with croup

Researchers said they found “compelling evidence” that the omicron variant of SARS-CoV-2 may cause croup in children.

“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 coinfection with another virus,” Ryan C.L. Brewster, MD, a resident in pediatrics at Boston Children's Hospital and Boston Medical Center, and colleagues wrote in Pediatrics.

One such case report, published last month in The Pediatric Infectious Disease Journal by researchers at Gazi University Hospital in Turkey, involved a healthy 23-month-old infant who suddenly had a fever and a “barking” cough, and was admitted to the hospital’s PICU during Turkey’s omicron wave.

Tests for adenovirus, rhinovirus, influenza and others came back negative, but a nose swab for SARS-CoV-2 was positive.

“The patient was diagnosed with SARS-CoV-associated croup and was treated on the first day with” dexamethasone and inhaled adrenaline, they wrote. “Since stridor and tachypnea continued 10 hours after the first dose of dexamethasone, a second dose of 0.6 mg/kg dexamethasone and inhaled adrenaline treatment was given the next day. Noisy breathing and tachypnea resolved after 24 hours.”

The patient was discharged on the third day of stay, the researchers said, and their issues had resolved by the seventh day.

“We recommend that one of the causes of croup in children is COVID-19 and that COVID-19 should be added to the viral panel to determine the origin of croup,” they wrote. “We would also like to point out that COVID does not contribute to the severity of croup and may not be an indicator for complications such as” multisystem inflammatory syndrome in children.

In their study, Brewster and colleagues examined children diagnosed with COVID-19 with a recorded case of laryngotracheitis between March 1, 2020, and Jan. 15, 2022.

They found that 75 children were diagnosed with COVID-19-associated croup, with 81% of the cases occurring during the omicron wave. The median length of hospital stay was 1.7 days, during which time the patients were given dexamethasone and/or racemic epinephrine.

Among the children who were tested for other viruses, only one test came back positive — for rhinovirus.

“Taken together; our preliminary findings lend compelling evidence to the hypothesis that the omicron variant causes laryngotracheobronchitis,” Brewster and colleagues wrote.

“Two years into the COVID-19 pandemic, the pathogenicity, infectivity, and manifestations of new variants of SARS-CoV-2 have been dynamic and unique,” they wrote. “Croup may represent yet another such novel presentation. Further research is needed to characterize the underlying mechanisms of COVID-19-associated croup, differences in clinical features from other viral etiologies, and appropriate management strategies in the SARS-CoV-2 era.”

References:

Brewster R, et al. Pediatrics. 2022;doi:10.1542/peds.2022-056492.

Dasdemir S, et al. Pediatr Infect Dis J. 2021;doi:10.1097/INF.0000000000003565.