Understanding the environmental factors related to the decrease in Pediatric Emergency Department referrals for acute asthma during the SARS-CoV-2 pandemic

Abstract

Background: Asthma exacerbations, a common reason for Pediatric Emergency Department (PED) referral, can be triggered by multiple factors, including infections, air pollution and allergens. Lockdown measures and other public health interventions during the SARS-CoV-2 pandemic determined radical changes to behavioral and social habits, that were reflected by a reduction in the transmission of all respiratory pathogens and in the emissions of relevant air pollution anthropogenic sources. Objective: This study aims to describe how restrictions during SARS-CoV-2 pandemic impacted the PED referral for asthma exacerbations and their potentially associated environmental triggers in densely populated urban areas. Methods: PED referrals for acute asthma from 2015 to 2020 were compared to air pollution and pollen data. To this purpose, historical daily concentration records of PM2.5, PM10 (including specific chemical tracers), as well as NO2, C6H6, tree, grass and weed pollen were analyzed. Results: In 2020, asthma-related PED referrals decreased up to 85%, compared to the average referral rate of the previous 5 years (P<0.01). The drastic drop in PED referrals was associated with a reduction of high-priority cases by 50-60%, unlike PED referrals for overall diagnoses, showing a larger contribution for severe outcomes. A concomitant diminished contribution of traffic-related air pollution was shown. Conclusions: The lower rate of asthma exacerbations in childhood can be related to synergic interactions of the multiple effects of lockdown measures which induced lower viral infection rates and decreased exposure to outdoor allergens. The reduction of traffic-related air pollution determined a weakening of inflammatory properties of urban PM.

Air pollution and childhood asthma

“…However, when the restrictions were lifted, there were increased visits during the fall but SO 2 levels remained low, raising the possibility for other driving factors [49]. In Europe, there was an observed decline both pollutant levels and ED visits [50,53] and hospitalizations due asthma exacerbations [54]. Conversely, Sayed et al [55] reported a reduction in pediatric asthma-related healthcare visits but not observe changes in air pollutant levels of PM 2.5 , PM 10 , O 3 and NO 2 during that time period when compared with previous historic trends.…”

Allergic diseases and immunodeficiencies in children, lessons learnt from COVID‐19 pandemic by 2022: A statement from the EAACI‐section on pediatrics

“…Although there were detrimental effects on children and young people's physical and mental well-being during the pandemic, some studies reported improvements in seasonal respiratory allergy symptom control, particularly during lockdown measures. 52,53 Nonpharmaceutical interventions, such as handwashing, masks, and social/physical distancing, reduction in the concentrations of traffic-related air pollutants 54,55 and decline in other respiratory infections incidence, may have contributed to reduced impact on allergic disease 56,57 particularly respiratory, [58][59][60][61][62][63] number of exacerbations 59,62,[64][65][66][67][68][69][70][71] and the odds of emergency room visit and/ or hospital admissions. 59,66,[72][73][74][75][76][77][78] Improvements were normally associated with time spent at home, and stronger effects were found in some studies among individuals with severe disease.…”