By Nancy Deutsch
NEW YORK, Jun 22 (Reuters Health) - Hay fever sufferers with stuffy noses
and the perpetual urge to sneeze may have heard that heat and humidity can help
ease the symptoms, and this is true, researchers report. But the effect ends the
minute the allergy sufferer leaves the tropical conditions.
"The bottom line is it seems it's good for you, but only as long as you're
exposed to it," said Dr. Fuad M. Baroody of the Section of Otolaryngology-Head
and Neck Surgery at the University of Chicago, Illinois.
Baroody and colleagues studied the effects of exposing people with allergic
rhinitis (hay fever) to heat and humidity for an hour, either in an
environmentally controlled chamber or by breathing in the hot and humid air
through a mask. The sufferers sneezed less and felt less congested with either
exposure, but had slightly fewer symptoms when using the mask, the researchers
report in the June issue of the Archives of Otolarygnology-Head and Neck
Surgery.
Previous research had shown being exposed to heat and humidity in a chamber
helped those with allergic rhinitis, Baroody noted. They wanted to replicate the
study, and learn whether just using a mask would be as good, or better, he told
Reuters Health.
Eighteen people took part in four phases of the study. They were all exposed
to heat of 37 degrees Celsius and relative humidity greater than 90% in a
chamber or through a face mask, and all were exposed to room temperature air in
similar ways. At the same time, the participants were exposed to two doses of an
allergen. Their reactions to the allergen were recorded.
All participants had fewer symptoms with the hot and humid air, but did
slightly better with just the mask, the researchers found.
However, the benefits of being exposed were short-lived. When asked to
return 24 hours later for testing, all of the subjects had the same runny noses
and congestion they had reported before being exposed to any hot air or
humidity. "The effect was not prolonged," Baroody said.
It is believed that both the heat and humidity do help symptoms, because
when the nasal temperature is raised, a person's response to an allergen is
inhibited, he explained. In addition, when you change the humidity, the
composition of the nose secretions change--diluting the nasal discharge, helping
to ease congestion.
There may eventually be a treatment that manages to keep the air entering
the nose hot and humid for prolonged periods of time, but it is not available
yet, Baroody said. While it is understandable that people want more natural
treatments, "we have good drugs for allergies. The stronger drugs do a better
job than this," he said.
