It is no skin off my nose: The relationship between the skin and allergic rhinitis.

OBJECTIVE: Evidence supports the relationship between the skin barrier and allergic conditions. This narrative review evaluates what role the cutaneous barrier may play in the pathogenesis, disease course, and management of allergic rhinitis (AR). DATA SOURCES: A literature review of the MEDLINE (PubMed), Embase, Cochrane, and SCOPUS Sciverse databases was conducted to identify available evidence. Reference lists of pertinent papers were searched using a snowball technique. STUDY SELECTIONS: Papers published in English from all years until December 2020 were included. Papers that did not address the relationship between AR and the skin and hypothesis papers were excluded. RESULTS: The cutaneous barrier shares histologic characteristics with the sinonasal epithelial barrier, which may explain commonalities between AR and atopic dermatitis. A disruption in the epithelial barrier could be a common pathway in the development of multiple allergic conditions. The skin is a common target for the treatment of AR. Available data that look at the relationship between the skin and AR often include other topics such as other atopic disorders and the role of the epithelial barrier. Increased understanding of how the cutaneous barrier affects AR may lead to new innovations in its management. CONCLUSION: The connection between the cutaneous barrier and AR holds possibilities for further investigation, and these may lead to a better understanding and future innovations for all atopic diseases.

Air Pollution and Allergic Rhinitis: Role in Symptom Exacerbation and Strategies for Management.

This article reviews the current understanding of the role of air pollution in both the symptom exacerbation and rising prevalence of allergic rhinitis (AR) for the development of future AR therapeutics and management strategies. We discuss the epidemiological evidence for this relationship through birth cohort studies, the economic impact of AR, and the influence of air pollution through the lens of the exposome framework of allergic disease development. This is followed by a discussion on the influence of diesel exhaust and diesel exhaust particles (DEP) from motor vehicle emissions and their implication in the rising prevalence of allergic disease and allergic sensitization through triggering inflammatory signalling pathways that exacerbate AR symptoms. Finally, a summary is provided of clinical trials assessing the influence of air pollution on AR with a depiction of currently available therapies and management strategies. Future directions in the development of AR modalities given the air pollution-mediated symptom exacerbation are challenged with unfolding the complex gene-environment interaction product of heterogenous AR presentation.