July 29, 2004 -- New research suggests nearly 8 million Americans -- almost 3% of the U.S. population -- routinely suffer from excessive sweating, a figure higher than previously believed.
"We're not talking about someone who gets a good sweat from a workout," says dermatologist Dee Anna Glaser, MD, of Saint Louis University, who conducted the study. "We're talking about a person who is sitting at their desk in a cool office, and going through their T-shirt, their shirt, and maybe even their jacket, with underarm sweat stains. Teenagers who are afraid to be called on in class because they are dripping in sweat. Babies who can't hold their bottles because they slip from the sweat in their palms."
They are victims of hyperhidrosis, a condition that causes them to sweat excessively on specific areas -- their underarms, face, palms, or the soles of their feet.
"I have women patients who only wear black because it's the only color that doesn't show the stains under their arms," says Heidi Waldorf, MD, director of laser and cosmetic surgery at Mt. Sinai School of Medicine in New York, who was not involved in Glaser's research but says it doesn't surprise her. She says that people who suffer from hyperhidrosis frequently carry numerous outfits to change into throughout the day.
"I hear the same stories over and over again," Waldorf tells WebMD. "It's an incredibly embarrassing condition, especially since we think of people who sweat profusely as being untrustworthy, devious, and anxious."
Many Affected, Few Seek Help
And apparently, it's a condition more common than previously believed, according to Glaser's research, published in the August issue of the Journal of the American Academy of Dermatology. In her study, she and her colleagues surveyed 150,000 households across the country. Nearly 3% of those surveyed -- some 6,800 people -- met the criteria for having the condition. She says some past research has estimated that less than 1% of the population has hyperhidrosis.
"I'm a little surprised at the high percentage of those affected," Glaser tells WebMD. "But what really surprised me is how many people -- approximately two in three -- had never spoken to a health professional about their condition, many thinking that nothing can be done about it."
But there are several medical and surgical treatments available, including Botox injections, which this month was approved by the FDA to treat "primary axillary hyperhidrosis" -- severe underarm sweating. That approval was based in part by another study by Glaser, expected to be published in coming months.
The 'Home-Run' Treatment
Botox, is derived from the bacterium Clostridium botulinum. It blocks nerves that trigger the sweat glands. Despite the recent FDA approval, Botox injections have been used by dermatologists for about 10 years -- not only to treat underarm hyperhidrosis, but also that of the palms, soles, and face.
Other available treatments include:
- Prescription antiperspirants, the typical first-line treatment. "They work but can cause skin irritation, redness, and stinging," says Glaser.
Medications such as antidepressants, tranquilizers, and a type of high blood pressure medication known as calcium channel blockers. These drugs, which have a "drying" effect, are primarily used to control sweating caused by stressful situations.
Surgery to either remove the sweat glands or sever nerves leading to them. But in the procedure to remove underarm sweat glands, range of motion problems of the arm are a common side effect, says Glaser.
"But with Botox, you hit a home run every time," says Glaser, vice chairwoman of the department of dermatology at Saint Louis University School of Medicine.
Waldorf agrees and tells WebMD that Botox injections are even used "cosmetically" in people who don't have hyperhidrosis but want to ensure they don't sweat during special occasions.
"Let's say you're making an important presentation or it's your wedding and you are concerned about sweating too much. You get an injection," she says. "Even celebrities are getting Botox injection in the weeks before the Academy Awards because they know they'll be on stage in expensive dresses."
Are You at Risk?
The exact cause of hyperhidrosis is not completely understood. "We've determined that these patients have sweat glands that are normal in size, number, and function," Glaser tells WebMD. "What seems to be driving this is that signals from the brain cause these people to sweat excessively, not because of heat or from exercise, when it's not necessary to control that much to maintain normal body temperature."
The condition affects men and women equally and has no geographic influence -- those in colder climates are as prone as those in hotter areas. It does seem to run in families, with about half of patients reporting a similarly afflicted relative, says Glaser. It typically first appears following puberty and rarely affects infants.
"What separates hyperhidrosis from other sweating is its excessiveness and the fact that it is localized to specific areas," says Glaser. "With menopause, you may sweat all over. With hyperhidrosis, you only sweat in your underarms or palms or soles or face, either an individual or some combination of those specific areas."
And unlike the sweating that may accompany social anxiety disorder, hyperhidrosis often occurs in "calm," everyday situations -- although it can be aggravated by stressful events.
"It's not a subtle thing, and most people with it know they have it," adds Waldorf. "This research shows what we've suspected -- that it is more common than some believed. Hopefully, people with this disease will also learn that it can be effectively treated."