Prevalence and Outcome of Asthma in Adult Patients Admitted to the Emergency Department for COVID-19: A Case-Control Study

(1) Background: Viral respiratory infections are common triggers for asthma exacerbation, often leading patients to the emergency department (ED). COVID-19, the disease caused by the SARS-CoV-2 virus, typically presents with respiratory symptoms, from minor symptoms, up to and including severe acute respiratory failure. Data on the association between asthma and COVID-19 are conflicting, and those from an ED setting are scarce. Our aims were to assess the prevalence and outcome of patients with asthma admitted to the ED for COVID-19. (2) Methods: We performed a case-control study, extracting data from a registry of adult patients with confirmed COVID-19 consecutively admitted to the ED of our hospital between March 2020 and January 2021. (3) Results: We identified 83 patients with asthma out of 935 individuals (prevalence 8.9%). There were no significant differences between cases and controls regarding both the proportion of hospital admissions and patients with critical COVID-19. (OR 1.37; 95% CI 0.52-3.56; and (OR 0.74; 95% CI 0.31-1.78 respectively). (4) Conclusions: In patients admitted to the ED for COVID-19, the prevalence of asthma was not higher than expected, and asthma was not associated with a worse outcome, in terms of the rate of hospitalization and critical COVID-19 disease.