Epidemiology of Asthma in Patients with COVID-19: Investigation of Respiratory Allergy as a Risk Factor for COVID-19 Severity

BACKGROUND: The outcome of coronavirus disease 2019 (COVID-19) is complicated by various comorbidities; asthma, a common chronic disease, may be considered one of these conditions. This study aimed to investigate the effect of asthma as a potential comorbid condition on the COVID-19 prognosis. MATERIALS AND METHODS: This retrospective study included all RT-PCR confirmed COVID-19 cases recorded on the Shiraz health department's electronic database from January to May 2020. A questionnaire was designed to collect information about patients' demographics, their history of asthma and other comorbidities, and the severity of COVID-19 by contacting them by phone. RESULTS: Of 3163 COVID-19 patients, 109 (3.4%) had self-reported asthma with a mean age of 42.7 ± 19.1 years. Most patients (98%) had mild-to-moderate asthma, while 2% had severe disease. Among asthmatic patients, fourteen (12.8%) were admitted to the hospital, and five (4.6%) died. Univariate logistic regression results showed that asthma had no significant effect on hospitalization (OR 0.95, 95% CI: 0.54–1.63) and mortality (OR 1.18, 95% CI: 0.48–2.94) in patients with COVID-19. Compared living and deceased patients with COVID-19, the pooled OR was 18.2 (95% CI: 7.3–40.1) for cancer, 13.5 (95% CI: 8.2–22.5) for age 40–70 years, 3.1 (95% CI: 2–4.8) for hypertension, 3.1 (95% CI: 1.8–5.3) for cardiac disease and 2.1 (95% CI: 1.3–3.5) for diabetes mellitus. CONCLUSION: This study showed that asthma is not associated with an increased risk of hospitalization and mortality in patients with COVID-19. Further studies are needed to investigate the risk of different asthma phenotypes on the severity of COVID-19 disease.