The Impact of SARS-CoV-2 Infection on Symptom Control and Lung Function in Children with Asthma.

Little is known about the long-term impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on children with asthma. To determine whether SARS-CoV-2 infection affects symptom control and lung function in children with asthma. Using data from clinical registries and the electronic health record, we conducted a prospective case-control study of children with asthma aged 6-21 years who had (cases) or did not have (control subjects) SARS-CoV-2 infection, comparing baseline and follow-up asthma symptom control and spirometry within an ∼18-month time frame and, for cases, within 18 months of acute coronavirus disease (COVID-19). A total of 171 cases had baseline and follow-up asthma symptom data, and 114 cases had baseline and follow-up spirometry measurements. There were no significant differences in asthma symptom control ( = 0.50), forced expiratory volume in 1 second ( = 0.47), forced vital capacity ( = 0.43), forced expiratory volume in 1 second/forced vital capacity ( = 0.43), or forced expiratory flow, midexpiratory phase ( = 0.62), after SARS-CoV-2 infection. Compared with control subjects (113 with symptom data and 237 with spirometry data), there were no significant differences in follow-up asthma symptom control or lung function. A similar proportion of cases and control subjects had poorer asthma symptom control (17.5% vs. 9.7%;  = 0.07) or worse lung function (29.0% vs. 32.5%;  = 0.50) at follow-up. Patients whose asthma control worsened after COVID-19 had a shorter time to follow-up (3.5 [1.5-7.5] vs. 6.1 [3.1-9.8] mo;  = 0.007) and were more likely to have presented with an asthma exacerbation during COVID-19 (46% vs. 26%;  = 0.04) than those without worse control. We found no significant differences in asthma symptom control or lung function in youth with asthma up to 18 months after acute COVID-19, suggesting that COVID-19 does not affect long-term asthma severity or control in the pediatric population.