Allergies May Actually Help Fend Off the Common Cold
June 6, 2000 -- Experts have long speculated that children, and possibly
adults, with allergies and asthma get more colds than other people. But new
research suggests that instead, allergies might actually help to lessen colds'
severity and duration.
Surprised? So were the researchers, who say the findings of their small
study were the opposite of what they expected to find. The study's results were
published in the Journal of Allergy and Clinical Immunology.
The findings are important because understanding why some cold sufferers
have many symptoms while others have just one or two may someday help
scientists develop vaccines to protect against the common cold.
"These findings suggest that [allergies] may not predispose people to
more severe colds," study author Pedro C. Avila, MD, tells WebMD. "What
we found was just the opposite of what we had thought." Avila is an
assistant clinical professor in the department of medicine at the University of
California-San Francisco's Cardiovascular Research Institute.
For the study, the researchers injected 20 allergy patients with rhinovirus
infection, also known as the common cold. Then they divided the patients into
two groups, and injected one group with substances known to cause allergic
reactions, such as pollen. This group actually stayed well longer, and, when
they did develop cold symptoms, their colds didn't last as long as those of the
The researchers believe that the results show that multiple allergens within
the nose do not worsen cold symptoms. Instead, they say, allergies may
significantly shorten the duration of cold symptoms, and those symptoms might
"Allergens, per se, may not be what makes the cold worse -- maybe some
people just get more severe colds," James F. Gern, MD, associate professor
of pediatrics at the University of Wisconsin Hospital in Madison, tells
Gern was not involved in this study, but has performed similar studies with
different results. No one has undertaken a study like this one before, he says,
and the findings may shed light on several aspects of the common cold.
Future studies will be important to confirm these findings, and researchers
are now focusing on why people get colds, why some people get worse symptoms,
and why some people never get sick, Gern says. "We see huge differences in
how severe colds are. This study represents a good step forward in
understanding what happens during a cold," he adds.
Avila plans future research to learn more about cold symptoms and their
- In a finding that surprised researchers, exposing people with allergies to
both the common cold virus and to allergens resulted in a shorter, milder cold,
compared to those who were exposed only to the cold virus.
- Allergies do not predispose people to more severe colds and may actually
lessen them, but scientists cannot yet explain this finding.
- More studies are needed to determine why people get colds and why some
people have more severe colds.