Analysis: Pediatric Allergic Rhinitis Doubled in Japan Over 40 Years

Key Takeaways

• A 40-year epidemiologic survey found allergic rhinitis, allergic conjunctivitis, and Japanese cedar pollinosis increased substantially among children in Japan between 1992 and 2022.
• Atopic dermatitis and bronchial asthma prevalence declined over the same period, suggesting divergent trends among pediatric allergic diseases.
• Family history of allergy and respiratory infections before age 2 years remained strongly associated with allergic disease prevalence across survey phases.

A 40-year epidemiologic analysis published in the World Allergy Organization Journal showed an increases in allergic rhinitis (AR), allergic conjunctivitis (AC), and Japanese cedar pollinosis (JCP) among school-aged children in western Japan, while rates of atopic dermatitis (AD) and bronchial asthma (BA) declined over time.

Investigators analyzed data from the West Japan Study of Asthma and Allergies in Childhood (WJSAAC), a recurring survey conducted every 10 years between 1982 and 2022. The study included 29,553 to 55,388 children aged 6 to 12 years across 11 prefectures in western Japan, with response rates exceeding 90% in all survey phases.

Long-Term Pediatric Allergy Trends Show Sharp Rise in Allergic Rhinitis and Pollinosis

Between 1992 and 2022, the prevalence of AR increased from 15.9% to 33.9%, AC rose from 6.7% to 12.2%, and JCP climbed from 3.6% to 14.4%. In contrast, AD prevalence decreased from 17.3% to 13.0%, while BA prevalence also declined in recent survey phases. The combined prevalence of AR, AD, and BA increased from 29.4% in 1992 to 37.8% in 2022.

Researchers also observed that AR, AC, and JCP became more common with advancing school grade, particularly among boys. Except for AD, most allergic diseases showed higher prevalence in male participants. Okinawa consistently demonstrated lower prevalence rates for AR, AC, JCP, and AD vs. other prefectures.

Children with a family history of allergic disease or respiratory infections before age 2 years had significantly higher prevalence rates across allergic conditions. The authors noted that rising cedar and cypress pollen exposure may partially explain the increase in pollinosis-related disease.

Study limitations included reliance on questionnaire-based diagnoses without laboratory confirmation and the potential influence of COVID-19-related lifestyle changes on 2022 findings.

“Trends in the prevalence of allergic diseases vary by disease, and long-term studies using the same geographical area and methods, including investigation of confounding factors, are needed,” the authors wrote.

Source

Nishima S, Odajima H, Matsuzaki H, Tezuka J. World Allergy Organization Journal. 2025;19(6). Doi:10.1016/j.waojou.2026.101396