Childhood wheezing has been linked to many different causes, some of which are typical of childhood asthma and some of which are not. Previous studies have suggested early onset wheezing is associated with high levels of allergies, impaired lung function, and bronchial hyper-responsiveness. Children with the longest duration of wheezing also appear to have more severe asthma. However, some children who develop wheeze later in childhood end up with the same characteristics as those who begin wheezing early.
This study involved nearly 1,500 children born on the Isle of Wight in 1989. Researchers looked at when the wheezers in the group began wheezing, family history, including history of allergy and asthma, and socioeconomic factors such as parental smoking and low social class.
Results suggest inheritance is the prime cause of persistent childhood wheeze. However, exposure to adverse environmental factors early in life may be combining with genetics to produce an earlier onset of the wheezing in some children. Children not exposed to these hazards but with a family history that puts them at increased risk for wheezing are more likely to develop the condition later in childhood but are not more likely to escape it altogether.
Researchers thus believe that ,early and late onset persistent wheezers clearly possess a significant genetic predisposition to their disease and correction of factors such as early-life smoking exposure, recurrent chest infections, and social deprivation merely delay the inevitable.