Bidirectional changes in recorded pediatric asthma diagnoses with respiratory virus activity: A nationwide…

StudyAllergology international : official journal of the Japanese Society of Allergology· Aug 2026

Bidirectional changes in recorded pediatric asthma diagnoses with respiratory virus activity: A nationwide interrupted time-series analysis in Japan.

Naomi Matsumoto, Hisashi Ishida, Shunsaku Hayase … Takashi Yorifuji

Pediatric RespiratoryStudyQ1IF 4.6

Pediatric asthma diagnoses fell after COVID-19 lockdowns, rebounded when respiratory viruses returned

Bidirectional changes in recorded pediatric asthma diagnoses with respiratory virus activity: A nationwide interrupted time-series analysis in Japan.

Naomi Matsumoto … Takashi Yorifuji

Allergology international · Aug 2026 · Q1 in General Medicine

Background

Early-life respiratory infections are associated with subsequent asthma development; however, whether respiratory viruses contribute to asthma onset or merely unmask pre-existing susceptibility remains unclear.

Methods

We conducted a nationwide interrupted time-series study using Japan's National Database of Health Insurance Claims, covering approximately 99% of the population.

Results

asthma diagnoses roughly halved after lockdown restrictions began

IRR 1.40 (95% CI 1.12 to 1.74)

null 1

1.12

1.74

CI excludes the null - significant

More results

Atopic dermatitis showed attenuated changes at both points.

Rate differences were greatest in infants (0-1 years) at T1 and school-aged children (5-9 years) at T2.

Rhinovirus, respiratory syncytial virus, influenza, and Mycoplasma pneumoniae, but not SARS-CoV-2, correlated with asthma diagnoses in ecological analyses.

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Conclusion

Newly recorded pediatric asthma diagnoses showed bidirectional changes that paralleled respiratory virus suppression and resurgence, compatible with a possible contributory role of respiratory infections, particularly among infants and school-aged children.

Bidirectional changes in recorded pediatric asthma diagnoses with respiratory virus activity: A nationwide interrupted time-series analysis in Japan.

Bidirectional changes in recorded pediatric asthma diagnoses with respiratory virus activity: A nationwide interrupted time-series analysis in Japan.

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