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Virus-induced wheezing and asthma: An overview

Sujani Kakumanu, MD
Section Editors
Gregory Redding, MD
Robert A Wood, MD
Deputy Editor
Elizabeth TePas, MD, MS


Viral respiratory infections are the most common causes of wheezing in infants and young children and are common triggers of asthma exacerbations in adult and pediatric patients with preexisting asthma [1-4]. In addition, wheezing with viral illnesses, particularly with respiratory syncytial virus (RSV) and human rhinovirus (HRV), in infants and young children is associated with an increased risk of developing childhood asthma [5-10].

The mechanisms by which viral respiratory infections trigger wheezing and asthma exacerbations are reviewed here. The influence of viral infection on both the development and perpetuation of asthma is also discussed. Other issues relating to the pathogenesis of asthma are reviewed elsewhere. Treatment of virus-induced wheezing and asthma is also discussed separately. (See "Pathogenesis of asthma" and "Risk factors for asthma" and "Natural history of asthma" and "Treatment of recurrent virus-induced wheezing in young children".)


Viral respiratory infections interact with host factors to promote recurrent virus-induced wheezing and the development of asthma (figure 1) [11]. Respiratory symptoms with viral infections most likely result from virus-induced damage of the airway epithelium, followed by airway inflammation in a predisposed individual. Immune responses triggered by viral respiratory tract infections include enhanced allergic inflammation, increased granulocyte recruitment, promotion of cytokine production, and upregulation of the parasympathetic response (table 1). These proinflammatory responses further influence the host responses to other microbial infections, allergens, stress, and pollutants.

Epithelial cells – Respiratory epithelial cells are the initial site of viral inoculation and serve as the primary site of viral replication. Respiratory viruses, such as influenza and respiratory syncytial virus (RSV), cause cytopathic damage to airway epithelium, and these changes can affect the function of the epithelium and airway smooth muscle. In addition, disturbing the integrity of the epithelial layer may enhance mucosal permeability and increase exposure of inflammatory and antigen-presenting cells to allergens, other infections, and irritants.

Approximately 90 percent of rhinovirus human rhinovirus-A (HRV-A) and human rhinovirus-B (HRV-B) serotypes bind to respiratory epithelial cells via the intercellular adhesion molecule 1 (ICAM-1, also called CD54 [cluster of differentiation 54]), while a minority, belonging to the HRV-A group, bind to the very low density lipoprotein (VLDL) receptor [12,13]. CDHR3, a human cadherin-related family member 3 protein, mediates human rhinovirus-C (HRV-C) entry into host cells [14]. The receptor for HRV-C strains has not yet been identified.

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Literature review current through: Nov 2017. | This topic last updated: Sep 02, 2016.
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