Cookie Notice

This site uses cookies. By continuing to browse this site, you are agreeing to our use of cookies. Review our cookies information for more details.

skip to main content

When preexisting asthma and influenza collide – vaccination is critical

Published: November 12, 2022

Children with asthma are at increased risk for respiratory illness necessitating admission to a pediatric intensive care unit (PICU) due to infection with influenza viruses. Vaccination against influenza decreases this risk.
In this issue of The Journal of Allergy and Clinical Immunology: In Practice, Maddux, Grunwell, and colleagues examined hospital treatments and post-discharge respiratory sequelae in children who were admitted to a pediatric intensive care or high-acuity unit between November 2019 and April 2020 for influenza as part of the 17-site Pediatric Intensive Care Influenza Network Investigators (PICFLU) network. The authors hypothesized that children with pre-existing asthma were at higher risk of persistent respiratory impairments after discharge.

This study evaluated 165 children with critical influenza including 56 (34%) with preexisting asthma. In this cohort, influenza vaccination rates were low (~40%) amongst children with and without pre-existing asthma. During hospitalization, children with asthma more commonly received medicines used to treat asthma exacerbations (77%) compared to those without an asthma history (28%). Other hospitalization characteristics were similar between children with and without asthma: approximately one in four required ventilator support and similar average length of PICU (~2.5 days) and hospital stays (~5 days). Survey data were collected approximately 3 months after discharge from 46 of 55 (84%) patients with pre-existing asthma and 90 of 107 (84%) without pre-existing asthma. After discharge, children with pre-existing asthma reported asthma symptoms more frequently than those without asthma (78% vs. 3%) and were more likely to visit a respiratory specialist for their symptoms (52% vs. 20%). A similar proportion of children with versus without asthma had an emergency department visit (4.3% vs. 6.6%) or hospital readmission (8.6% vs. 3.3%) for a respiratory condition. Notably, one in ten children without preexisting asthma were newly diagnosed with asthma after hospitalization.

These results suggest that patients with and without pre-existing asthma had similar manifestations of severe illness including need for invasive ventilation. After discharge, respiratory symptoms were common, particularly amongst those with pre-existing asthma, and less than half of the cohort was evaluated by a respiratory specialist. Additionally, less than half were vaccinated against influenza. Advocating for infection prevention through vaccination and treatment of post-discharge morbidities may mitigate morbidities resulting from critical illness caused by influenza, particularly in children with pre-existing asthma.

The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.

Full Article