Recent prevalence of allergic rhinitis caused by house dust mites among the pediatric population in Fukui, Japan

Background: Allergic rhinitis (AR) is an IgE-mediated type I allergic chronic nasal disease common among all age groups, including the pediatric population. House dust mites (HDMs) are globally ubiquitous and the most important indoor aeroallergen. However, the recent prevalence of HDM-caused AR (AR-HDM) in Japan remains unknown, especially after the COVID-19 pandemic. Objective: The objective of this study was to investigate the current prevalence of AR-HDM, its clinical features, and the current status of medical examinations in elementary school students. Methods: A survey of 41,000 elementary school students was conducted during July 2021 in Fukui Prefecture, Japan. Parents were asked to complete a questionnaire that examined allergic disease history and clinical background. Results: A total of 17,974 subjects were analyzed in the study. The results showed that the current prevalence of AR-HDM in elementary school children is 18.8%. We found that AR-HDM had already developed before entrance into elementary school in 68.3% of affected subjects. Among these subjects, 82.3% had received some form of treatment, such as prescription medications, whereas 4.2% were treated by allergen immunotherapy. Multiple logistic regression analysis of the onset of AR-HDM revealed that male sex, being the first-born child, comorbidity of bronchial asthma, atopic dermatitis, food allergy, and allergic conjunctivitis are associated with development of AR-HDM. Conclusions: The present study revealed the prevalence of AR-HDM in elementary school children. The results emphasize the importance of appropriate diagnosis and treatment from infancy through early childhood.