Role of viral infections in asthma exacerbations

It is widely recognised that viral infections are the most frequent causes of asthma exacerbations both in children and in adults, being rhinovirus the most frequent identified virus. Despite optimised therapy, as suggested by International Guidelines, asthma exacerbations still occur Several data documents that rhinovirus is able to infect and replicate at lower airway epithelial level and is able to induce features of asthma including eosinophilic airway inflammation and to increase bronchial hyperresponsiveness. Furthermore, a recent study documented that asthmatic patients have an increased susceptibility of lower respiratory airways to rhinovirus infections that leads to increased lower respiratory tract symptoms compared to normal subjects. Further studies are needed to elucidate the complex immunological mechanisms that lead to asthma exacerbation after respiratory tract viral infection. Increasing the knowledge of these mechanisms will indeed offer new pharmacological targets to treat and prevent to asthma exacerbations.