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Poison
Can Control Sweating
Injections
of botulism toxin can control an embarrassing condition that makes
people sweat so heavily that their clothes get drenched at room
temperature, a study found.
The German
research adds to the growing list of diverse medical uses for
the powerful food-borne poison, which is already used in diluted
form to smooth out forehead wrinkles and ease migraine headaches.
``The effectiveness
is really hard to believe,'' said dermatologist Dr. Richard Glogau
of the University of California at San Francisco. Glogau said
the findings help establish the toxin as the treatment of choice
for hyperhidrosis, a sweating disorder that is thought to affect
1 million to 2 million Americans.
Hyperhidrosis,
whose cause is unknown, makes people sweat so profusely that they
are often humiliated at school or work. Sweaty palms prevent them
from shaking hands comfortably, gripping a tool securely or working
normally at a keyboard.
``The people
who suffer from it are enormously affected,'' said neurosurgeon
Dr. Raj Narayan of Temple University in Philadelphia, who operates
on some of these patients. ``They also suffer from the fact that
nobody else seems to think it's a particularly big deal.''
The nerve-paralyzing
botulism toxin is one of the most powerful poisons known to medicine
and is feared as a potential biological weapon.
In the study
published in Thursday's issue of The New England Journal of Medicine,
University of Munich doctors injected the diluted toxin into the
armpits of 145 patients with hyperhidrosis.
At the start
of the study, patients were producing sweat at a rate of up to
four cups over eight hours under both arms combined. Two weeks
after the injections, they were sweating an average of only 15
percent of the initial rate. The toxin reduced sweat to normal
levels in virtually all patients.
It works by
blocking the release of a chemical needed to transmit nerve signals
to muscles and sweat glands.
The effect
is temporary. Patients slowly began sweating more heavily after
two weeks. But even after 26 weeks, they were perspiring on average
less than half of their beginning rate. Injections must be repeated
every three to six months. The same treatment can be applied to
the hands.
Overall, the
botulism injections appear to be more effective than other treatments,
doctors said. In one technique, the hands are placed in water
and exposed to a weak electrical current. The direct application
of aluminum chloride, used in deodorants, also helps to dry armpits.
As a last resort, surgeons cut or crimp nerves that activate the
sweat glands.
However, the
toxin is expensive, with a typical treatment costing $1,000 to
$1,500 in this country. Insurance companies generally will not
cover the cost. There are also questions about whether repeated
treatments can cause nerve damage and over the frequency of allergic
reactions.
Reference
Source 89
On
the Net
American
Academy of Dermatology: http://www.aad.org
Information
on hyperhidrosis: http://www.excessivesweating.org
For more information
on how to prevent obesity or diabetes, use
PreventDisease.com's "Quick
Prevention Resources".
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