Mite allergen avoidance decreases allergic symptoms in children in Ishinomaki city of Japan after natural disasters

Abstract

Objective: We investigated the prevalence of asthma, rhinitis, and atopic dermatitis in children, evaluated the mite allergen levels in their bedding after the Great East Japan Earthquake, and assessed changes in allergic symptoms in children and their families after allergen avoidance practices. Methods: We performed a survey for the International Study of Asthma and Allergies in Childhood (ISAAC) comprising 1109 children, aged 7–8 years, living in Ishinomaki, Japan. We collected responses from 464 children, and in 2016, measured the level of Dermatophagoides group 1 (Der 1) in the bedding of 202 of these children. The intervention group of children attended at least one allergen avoidance seminar. The levels of Der 1 in their bedding were measured, along with changes in allergic symptoms, in 17 children in 2017 and 14 children in 2018. The nonintervention group comprised children who did not attend an allergen avoidance seminar at any time. Results: Of the 464 children who participated in the ISAAC, 50 (10.8%) reported having asthma, 179 (38.8%) allergic rhinitis, and 126 (27.3%) atopic dermatitis. The average level of Der 1 measured in the bedding of the 202 children in 2016 was 295.8 ng/m2. The levels of Der 1 in the intervention group—but not in the nonintervention group—significantly decreased in 2017 and 2018. The symptoms of asthma, allergic rhinitis, and atopic dermatitis in the children of intervention group and their families decreased after allergen avoidance practices. Conclusions: Allergen avoidance practices relieved allergic symptoms in school children after the Great East Japan Earthquake.