Allergies and asthma are a continuing health problem in most developed countries, but just how do these ailments develop over the course of a childhood? In a population-based study designed to help answer this question, researchers at the Norwegian University of Science and Technology (NTNU) found that 40 per cent - or two of five -- of nearly 5,000 two-year-olds had at least one reported allergy-related disorder. The most common symptom was wheezing, which was reported in 26 per cent of all children in the study, says Ingeborg Smidesang, a PhD candidate in the university's Faculty of Medicine, and the primary author of the study.
Researchers are careful to point out that there is no guarantee that children who wheeze at two years old will grow up with asthma. "One of the challenges here is that we don't know which wheezers will develop asthma", Smidesang says.
The findings are among the first to illustrate the scope of allergy-related problems in such a young group of children, and the challenges that these problems pose for both families and for public health systems overall. "If you think about something like moderate atopic eczema, which can involve quite a few doctor's visits, and a lot of work on the part of parents, it is quite a big deal", she says. "This can be quite a burden."
The study has been published in an online version of Pediatric Allergy and Immunology, a peer-reviewed academic journal. Among the findings reported is that fully 21 per cent of the 5000 children in the study, or about 1000 children, had been tested for allergies. Roughly 60 per cent of these 1000 children were reported by their parents to have had a positive allergy test. However, when researchers randomly selected 390 children for allergy testing, only eight per cent had a positive test. The allergy-related disorders that were studied were eczema, asthma, asthma-like symptoms and hay fever. Researchers found that boys were more likely than girls to have an allergy-related disorder, Smidesang said.