Respiratory allergens and asthma exacerbation

Introduction. - Asthma exacerbations are characterized by a progressive aggravation of respiratory symptoms such as dyspnea, cough, wheezing or chest tightness. Background. - The relationship between allergy and asthma exacerbations has been evaluated by epidemiological studies based on various criteria such as oral corticosteroid requirement, emergency room visits and hospital admission for asthma. Many studies have observed that deteriorating asthma can be related to increased exposure to allergens, particularly allergens from house dust mite, cockroach, cat, rodent, mold or pollen. Several studies have demonstrated that sensitization to respiratory allergens and allergen exposure increases the risk of exacerbation of asthma. When asthma exacerbations are work-related, occupational allergens may be implicated. Conclusions and perspectives. - Most studies provide evidence that allergen exposure contributes to the risk of asthma exacerbations, but other precipitating factors, such as viruses, can interact and increase the risk. (C) 2012 SPLF. Published by Elsevier Masson SAS. All rights reserved.