That news, published in The Lancet, comes from researchers including Sabina Illi, PhD, of University Children's Hospital in Munich, Germany.
Illi's team studied about 1,300 German children. The study started in 1990, when the kids were newborns, and ended 13 years later.
The children got regular checkups and allergy tests. When they were 7, 10, and 13 years old, they also took lung function tests. Their parents reported whether or not the kids wheezed.
Children who wheezed and were allergic to dust mites, cat dander, dog hair, or other common allergens in the first three years of life were most likely to develop asthma by age 13.
Their peers who wheezed but lacked allergies were different. Ninety percent of those kids lost their symptoms by the time they started school and had normal lung function at puberty.
"The timing of the process seems of importance," the researchers write.
Asthma risk was much more closely tied to allergies that started in the first few years of life than to allergies that started later on, the study shows.
The body's immune system takes years to mature, and the first three years may be especially important, note Illi and colleagues.
In light of their findings, children who use inhaled corticosteroids for wheezing should get regular checkups to see if they still need that medicine.
SOURCES: Illi, S. The Lancet, Aug. 26, 2006; vol 368: pp 763-70. News release, The Lancet.
By Miranda Hitti
Reviewed by Brunilda Nazario