Researchers have found that there is a strong relationship between children who suffer respiratory illness early in life and the risk of them developing asthma later.
"If you are exposed to an allergen for the first time, the body usually becomes tolerant of it. There is also pretty clear evidence that infections in general are likely to protect you from developing allergies," researcher Sebastian Johnston, of Imperial College London, told the Telegraph newspaper.
"It may be a matter of bad timing, so that if a child is exposed to an allergen at the same time as a virus infection, then the child might become sensitized to that allergen instead of being tolerant of it," he added.
The findings of the study challenged earlier research, which said that usual infections help guard kids by allowing them to build up a strong immune system, the Telegraph reported.
Researchers from the Imperial College, London and University of Western Australia, Perth studied nearly 200 children for five years under the study.
