Features of acute obstructive laryngitis (croup) in children during COVID-19

Croup causes a life-threatening condition in children. Objective : to study the etiological structure of acute obstructive laryngitis and to identify the clinical and immunological features of croup syndrome in children with COVID-19. Materials and methods . The article presents an analysis of the etiological structure of acute obstructive laryngitis in 897 children aged 6 months to 5 years. Etiological decoding was carried out by the PCR method, the cytokine status (the content of IFN-á and -ã, IL-1â, -8 and -17) was determined by the ELISA method in the material from the nasopharynx of patients. Patients with croup in coronavirus infection were divided into groups: Group I — children with seasonal coronaviruses ( n = 39), Group II — children with COVID-19 ( n = 30). Results. The proportion of viral acute obstructive laryngitis is 86.0%. The leading provocateurs of laryngeal stenosis are parainfluenza viruses (26.9%). Children with COVID-19 more often suffered from grade II laryngeal stenosis (60.0%) with dyspnea of mixed nature (26.7%) against the background of severe intoxication (63.3%) and moderate catarrhal syndrome (70.0%) with the addition of croup syndrome more often on the second (43.3%) and third (40.0%) days of the disease. Activation of local immunity and clinical symptoms of catarrhal-respiratory syndrome were due to an increase in the content of proinflammatory cytokines IL-1â, -8, -17 and the IL-17/IL-8 ratio in the pharyngeal secretion in children of group II with COVID-19, which correlated with low levels of IFN-á and -ã. Conclusion . Croup in COVID-19 in children is typical. Children with a complicated premorbid background are most susceptible, which correlated with low interferon levels and increased interleukins. Acute obstructive laryngitis in COVID-19 should be considered as one of the clinical manifestations of coronavirus infection.