To investigate the big data characteristics and trend changes of patients with allergic rhinitis (AR) who sought medical attention at our hospital before (from 2018 to 2019) and after (from 2020 to 2023) COVID-19, and provide reference basis for the treatment of AR. This study used a descriptive epidemiological method to analyze the big data and trend changes of AR patients. A total of 62,196 AR patients were collected, of whom 32,874 were male and 29,322 were female, with an age range of 1–89 years. The monthly change trend of AR patients showed a marked seasonality. The number of AR patients increased year by year. There was no significant difference in the number of patients between different genders. There was a significant difference in the number of patients between different age groups. The number of AR patients increased markedly from 2018 to 2023, and COVID-19 seems to have accelerated this process. There is a clear seasonal pattern. The number of boy patients is significantly higher than that of girl patients, and the change in female hormones may affect the incidence of AR. Therefore, it is necessary to update management measures and formulate relevant policies in response to the changing trend of AR since the COVID-19 epidemic.