|
If your baby has a runny nose it may actually be a good thing. It seems
that children who get such minor infections may be less likely to
develop asthma later on in life.
The findings appear to support the theory that common
infections shape the immature immune system in a way that cuts the
risk of asthma and allergies later in life.
The airway inflammation that marks asthma is often caused by an
abnormal immune reaction to environmental irritants such as pollen,
dust and mold. Previous studies have suggested that certain infections
early in life may ward off asthma by pushing the developing
immune system toward infection-fighting mode. This, the theory goes,
may make children's immune systems less likely to overreact to normally
benign environmental factors.
The investigators found that repeated "mild infections"
-- runny nose or infection with a herpes virus -- were linked
to a lower risk of
asthma and allergy.
On the other hand, repeated infections of the lower respiratory
tract, such as the flu or pneumonia, were associated with
a higher asthma risk. This, the
researchers report, suggests that children predisposed to asthma
may be more vulnerable to such infections.
Over the past 20 years, asthma has become more and more prevalent
worldwide. Some experts put part of the blame on the increasingly
sterile conditions in which children are growing up. They point
out that smaller families, fewer germs, and more antibiotics early
in life may be shaping children's immune systems to overreact to
normally harmless irritants.
British Medical Journal February
17, 2001; 322: 390-395
| 