Exposome and Respiratory Allergic Diseases: A Structured Narrative Review

Background: Allergic respiratory diseases, primarily asthma and allergic rhinitis, affect hundreds of millions worldwide. Their rising prevalence reflects complex gene–environment interactions that the exposome framework organizes into external, internal, and social domains shaping the development and progression of respiratory allergic diseases. Methods: Narrative review based on structured searches in PubMed/MEDLINE and Scopus (2015–2025), supplemented with 11 key references; 42 publications were selected from 1015 records. Results: Air pollution showed consistent but modest associations with asthma (HR 1.04–1.12); household dampness and mold showed larger effect sizes on symptom severity (OR 1.48–1.52); and occupational exposures showed the largest effect sizes across studies (RR 3.2–4.3). Systemic inflammation, oxidative stress, and nasal microbiome alterations were identified as internal mediators linking exposures to allergic phenotypes, though mechanistic pathways remain incompletely defined. Social exposome studies suggested context-dependent patterns: socioeconomic advantage correlated with greater sensitization in some settings, while deprivation could amplify disease progression and mortality risk (HR 1.18–1.32). Conclusions: The exposome offers a valuable integrative framework, but clinical translation is limited by scarce longitudinal multi-exposure studies and underrepresentation of low- and middle-income regions. Priorities include life-course cohorts integrating all three domains and targeted interventions in housing and occupational settings.