How does allergic rhinitis impact the severity of COVID-19?: a case–control study

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a contagious disease whose symptoms and risk factors are newly described. Some allergic diseases, including asthma, have been defined as risk factors for a poor outcome in COVID-19. We aimed to investigate the role of another allergic disease—allergic rhinitis—in the severity of COVID-19. METHODS: This case–control study was conducted at Sakarya Educational and Research Hospital, Toyota Hospital and Yenikent State Hospital between March 18, 2020 and August 30, 2020. The study included a case group of 125 randomly selected patients who had been diagnosed with allergic rhinitis in advance of having COVID-19 and a control group of 125 patients without allergic rhinitis who were diagnosed with COVID-19. We evaluated all participants’ statuses regarding smoking, symptoms, and hospitalization, as well as the length of their hospitalization and the number of their comorbidities. RESULTS: There were no statistically significant differences between the two groups regarding percentage of asymptomatic patients (p = 0.27), presence of smoking (p = 0.068), hospitalization status (p = 0.79), and hospitalization length (p = 0.55). From each group, two patients needed care in an intensive care unit (ICU). One patient from the case group and two from the control group died due to COVID-19. CONCLUSION: We found that allergic rhinitis did not affect the severity of COVID-19. However, we recommend that the literature be augmented with further studies on the COVID-19 prognosis of patients who have allergic rhinitis. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00405-021-06836-z.