Allergies, viruses and the risk of asthma at adolescence

Published Online: May 10, 2016

Asthma is the most common chronic respiratory disease in childhood and the most frequent cause of school absenteeism. Respiratory viral illnesses have long been known to cause wheezing illnesses in preschool children and many, but not all, children who suffer these illnesses in early life go on to develop childhood asthma by school age. The development of allergic sensitization to aeroallergens (e.g. mold, furry pets, dust mites) in early life has also been strongly linked to childhood asthma risk.

To investigate further the relationships between preschool respiratory viral wheezing illness and allergic sensitization on asthma risk and persistence over time, Rubner and colleagues longitudinally evaluated these interactions from birth to 13 years of age in a group of children participating in the Childhood Origins of ASThma (COAST) study. COAST children were at high risk for asthma based upon at least one parent having asthma and/or allergies. Nasal samples were obtained during preschool wheezing illnesses and evaluated for the presence of various respiratory viruses, the two most common being respiratory syncytial virus (RSV) and human rhinovirus (RV). COAST children were also evaluated by blood testing for the presence of allergic sensitization to environmental allergens (e.g. pollen, mold, dust mites, dogs, and cats).

In previous studies by other research groups, RSV wheezing illnesses were found to be associated with persistent wheezing (asthma) at six years of age but this association was lost by age 13 years. Rubner et al. found that preschool wheezing illnesses due to RV were significantly more likely to be associated with the persistence of asthma out to 13 years of age. An additional novel finding was that the younger the age of the development of allergic sensitization, and the greater number of allergens the child developed an allergy to, the greater was his or her risk of developing asthma. Thus, RV wheezing illnesses and the timing and magnitude of the development of allergic sensitization in early life significantly influence the development of asthma by school age, and this effect appears to last at least through the beginning of adolescence.  These findings identify early life RV wheezing and aeroallergen sensitization as two potentially modifiable risk factors to target in order to prevent the development of asthma in children.

The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

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