Age-specific incidence of allergic and non-allergic asthma

• Published in: BMC pulmonary medicine Vol. 20; no. 1; p. 9
• Main Authors: Pakkasela, Johanna, Ilmarinen, Pinja, Honkamäki, Jasmin, Tuomisto, Leena E., Andersén, Heidi, Piirilä, Päivi, Hisinger-Mölkänen, Hanna, Sovijärvi, Anssi, Backman, Helena, Lundbäck, Bo, Rönmark, Eva, Kankaanranta, Hannu, Lehtimäki, Lauri
• Format: Journal Article
• Language: English
• Published: London BioMed Central 10.01.2020; BioMed Central Ltd; BMC
• Subjects: Adolescent; Adult; adult-onset asthma; Adults; Age groups; Age-specific; Allergic; Allergic rhinitis; Allergies; Allergy; Asthma; Asthma and allergic disorders; Atopy; Child; Childhood; Childhood asthma; Children; Cluster analysis; common allergens; Critical Care Medicine; Development and progression; Diagnosis; Disease age factors; Epidemiology; helsinki; Hypersensitivity; Immunologi inom det medicinska området; Immunology in the Medical Area; Incidence; Intensive; Internal Medicine; Lungmedicin och allergi; Medicine; Medicine & Public Health; Non-allergic; Onset; phenotypes; Physicians; Pneumology/Respiratory System; Population; Prevalence; Pulmonology; reported asthma; Research Article; Respiratory Medicine and Allergy; Respiratory System; Rhinitis; risk-factors; sensitization; Studies; Surveys; Womens health; Young adults; Finland; Sweden; Non-allergic; Prevalence; Adolescent; Adult; Child; Allergic; Age-specific; Asthma; Incidence; Onset
• ISSN: 1471-2466; 1471-2466
• DOI: 10.1186/s12890-019-1040-2

Background Onset of allergic asthma has a strong association with childhood but only a few studies have analyzed incidence of asthma from childhood to late adulthood in relation to allergy. The purpose of the study was to assess age-specific incidence of allergic and non-allergic asthma. Methods Questionnaires were sent to 8000 randomly selected recipients aged 20–69 years in Finland in 2016. The response rate was 52.3% ( n  = 4173). The questionnaire included questions on e.g. atopic status, asthma and age at asthma diagnosis. Asthma was classified allergic if also a physician-diagnosed allergic rhinitis was reported. Results The prevalence of physician-diagnosed asthma and allergic rhinitis were 11.2 and 17.8%, respectively. Of the 445 responders with physician-diagnosed asthma, 52% were classified as allergic and 48% as non-allergic. Median ages at diagnosis of allergic and non-allergic asthma were 19 and 35 years, respectively. Among subjects with asthma diagnosis at ages 0–9, 10–19, 20–29, 30–39, 40–49, 50–59 and 60–69 years, 70, 62, 58, 53, 38, 19 and 33%, respectively, were allergic. For non-allergic asthma, the incidence rate was lowest in children and young adults (0.7/1000/year). It increased after middle age and was highest in older age groups (2.4/1000/year in 50–59 years old). Conclusions The incidence of allergic asthma is highest in early childhood and steadily decreases with advancing age, while the incidence of non-allergic asthma is low until it peaks in late adulthood. After approximately 40 years of age, most of the new cases of asthma are non-allergic.