Hyperhidrosis is a disorder marked by excessive sweating. It usually begins at puberty and affects the palms, soles, and armpits.
Sweating is the body's way of cooling itself and is a normal response to a hot environment or intense exercise. However, excessive sweating unrelated to these conditions can be a problem for some people. Those with constantly moist hands may feel uncomfortable shaking hands or touching, while others with sweaty armpits and feet may have to contend with the unpleasant odor that results from the bacterial breakdown of sweat and cellular debris (bromhidrosis). People with hyperhidrosis often must change their clothes at least once a day, and their shoes can be ruined by the excess moisture. Hyperhidrosis may also contribute to such skin diseases as athlete's foot (tinea pedis) and contact dermatitis.
In addition to excessive sweat production, the texture and color of the skin itself may be affected by hyperhidrosis. The skin may turn pink or bluish white. Severe hyperhidrosis of the soles of the feet may produce cracks, fissures, and scaling of the skin.
Hyperhidrosis in general and axillary hyperhidrosis (excessive sweating in the armpits) in particular are more common in the general population than was previously thought. A group of dermatologists in Virginia reported in 2004 that 2.8% of the United States population, or about 7.8 million persons, have hyperhidrosis. Of this group, slightly more than half (4 million persons) have axillary hyperhidrosis. One-third of the latter group, or about 1.3 million persons, find that the condition significantly interferes with daily activities and is barely tolerable. Only 38%, however, had ever discussed their excessive sweating with their doctor.
Causes and symptoms
There are three basic forms of hyperhidrosis: emotionally induced; localized; and generalized. Emotionally induced hyperhidrosis typically affects the palms of the hands, soles of the feet, and the armpits. Localized hyperhidrosis typically affects the palms, armpits, groin, face, and the area below the breasts in women, while generalized hyperhidrosis may affect the entire body.
Hyperhidrosis may be either idiopathic (of unknown cause) or secondary to fever, metabolic disorders, alcoholism, menopause, Hodgkin's disease, tuberculosis, various types of cancer, or the use of certain medications. The medications most commonly associated with hyperhidrosis are propranolol, venlafaxine, tricyclic antidepressants, pilocarpine, and physostigmine.
Most cases of hyperhidrosis begin during childhood or adolescence. Hyperhidrosis that begins in adult life should prompt the doctor to look for a systemic illness, medication side effect, or metabolic disorder.
Hyperhidrosis affects both sexes equally and may occur in any age group. People of any race may be affected; however, for some reason unknown as of the early 2000s, Japanese are affected 20 times more frequently than members of other ethnic groups.
Hyperhidrosis is diagnosed by patient report and a physical examination. In many cases the physician can directly observe the excessive sweating.
The doctor may also perform an iodine starch test, which involves spraying the affected areas of the patient's body with a mixture of 500 g of water-soluble starch and 1 g iodine crystals. Areas of the skin producing sweat will turn black.
The doctor will order other laboratory or imaging tests if he or she suspects that the sweating is associated with another disease or disorder.
Most over-the-counter antiperspirants are not strong enough to effectively prevent hyperhidrosis. To treat the disorder, doctors usually prescribe 20% aluminum chloride hexahydrate solution (Drysol), which the patient applies at night to the affected areas that are then wrapped in a plastic film until morning. Drysol works by blocking the sweat pores. Formaldehyde- and glutaraldehyde-based solutions can also be prescribed; however, formaldehyde may trigger an allergic reaction and glutaraldehyde can stain the skin (for this reason it is primarily applied to the soles). Anticholinergic drugs may also be given. These drugs include such medications as propantheline, oxybutynin, and benztropine.
Injections of botulinum toxin (Botox) given under the skin work well for some patients. Botox works to stop the excessive sweating by preventing the transmission of nerve impulses to the sweat glands. These injections must be repeated every 4-12 months, however.
In addition, an electrical device that emits low-voltage current can be held against the skin to reduce sweating. These treatments are usually conducted in a doctor's office on a daily basis for several weeks, followed by weekly visits. Dermatologists also recommend that patients wear clothing made of natural or absorbent fabrics also may help, avoid high-buttoned collars, use talc or cornstarch, and keep underarms shaved.
The only permanent cure for hyperhidrosis of the palms is a surgical procedure known as a sympathectomy. To treat severe excessive sweating, a surgeon can remove a portion of the nerve near the top of the spine that controls palm sweat. However, not very many neurosurgeons in the United States will perform the procedure, because it often results in compensatory sweating in other regions of the body. Alternatively, it is possible to surgically remove the sweat gland-bearing skin of the armpits, but this is a major procedure that may require skin grafts.
More recently, liposuction under the armpits has been successfuly used to treat hyperhydrosis in this region of the body. The liposuction removes some of the excess sweat glands responsible for axillary hyperhidrosis. The procedure also has the advantage of leaving smaller scars and being less disruptive of the overlying skin.
Hyperhidrosis is not associated with increased mortality; it primarily affects the patient's quality of life rather than longevity. While the condition cannot be cured without radical surgery, it can usually be controlled effectively.
Beers, Mark H., MD, and Robert Berkow, MD., editors. "Disorders of Sweating." Section 10, Chapter 124 In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.
Altman, Rachel, MD, George Kihiczak, MD, and Robert Schwartz, MD. "Hyperhidrosis." eMedicine August 18, 2004. 〈http://www.emedicine.com/derm/topic893.htm〉.
Licht, P. B., and H. K. Pilegaard. "Severity of Compensatory Sweating after Thoracoscopic Sympathectomy." Annals of Thoracic Surgery 78 (August 2004): 427-431.
Strutton, D. R., J. W. Kowalski, D. A. Glaser, and P. E. Stang. "US Prevalence of Hyperhidrosis and Impact on Individuals with Axillary Hyperhidrosis: Results from a National Survey." Journal of the American Academy of Dermatology 51 (August 2004): 241-248.
American Academy of Dermatology (AAD). P. O. Box 4014, Schaumburg, IL 60168-4014. (847) 330-0230. 〈http://www.aad.org〉.
Anticholinergic drugs— Drugs that block the action of the neurotransmitter acetylcholine.
Axilla (plural, axillae)— The medical term for the armpit.
Bromhidrosis— Bacterial breakdown of sweat and cellular debris resulting in a foul odor.
Contact dermatitis— Skin inflammation that occurs when the skin is exposed to a substance originating outside of the body.
Idiopathic— Of spontaneous origin or unknown cause. Many cases of hyperhidrosis are idiopathic.
Sympathectomy— Surgical cutting or interruption of any of the pathways in the sympathetic nervous system. It may be performed to control hyperhidrosis that does not respond to medications.
Sympathetic nervous system— The part of the nervous system that originates in the lumbar and thoracic portions of the spinal cord. It regulates involuntary reactions to stress, including sweating as well as heart rate, breathing rate, and digestive secretions.
Tinea pedis— Fungal infection of the feet of the skin characterized by dry, scaly lesions.
Hyperhidrosis is a medical condition characterized by excessive sweating in the armpits, palms, soles of the feet, face, scalp, and/or torso.
Hyperhidrosis involves sweating in excess of the amount required normally for the body's level of activity and temperature. There are two types of hyperhidrosis—primary and secondary. In primary hyperhidrosis, the cause is unknown and excessive sweating is localized in the armpits, hands, face, and/or feet. Primary hyperhidrosis begins during childhood or early adolescence , gets worse during puberty , and lasts a lifetime. In secondary hyperhidrosis, which is less common than primary hyperhidrosis, excessive sweating is caused by another medical condition and usually occurs over the entire body. Medical conditions that can cause secondary hyperhidrosis include hyperthyroidism , menopause, obesity , psychiatric disorders, and diabetes. Secondary hyperhidrosis may also be caused by use of certain medications.
In about 60 percent of cases, the hands and feet are affected, and in about 30–40 percent of cases, the armpits are affected.
Axillary (underarm) hyperhidrosis occurs more frequently in females and in individuals of Asian or Jewish ancestry. Hyperhidrosis of the hands and feet occurs 20 times more frequently in the Japanese. Previously, it was thought that hyperhidrosis was rare, occurring in only 0.6–1 percent of adolescents and young adults; however, a national survey conducted in 2004 found that up to 2.8 percent of Americans (approximately 7.8 million individuals) may have hyperhidrosis.
Causes and symptoms
The exact cause of hyperhidrosis is as of 2004 unknown. Excessive sweating in the affected area is caused by overactivity of the nerves linked to the sweat glands. Specifically, acetylcholine, a chemical in the body that transmits nerve signals, is released from nerve endings and stimulates secretion of sweat. Genetics may also be a factor, since 25–40 percent of individuals with hyperhidrosis also have a family member with the condition.
In hyperhidrosis, sweating may be continuous or start suddenly. Usually, excessive sweating does not occur in response to exercise and does not occur during sleep . Emotional stress, high room/environmental temperature, and digestion of certain foods can aggravate hyperhidrosis. Symptoms of hyperhidrosis vary depending on the body area affected:
- In palmar hyperhidrosis, the palms of the hands are excessively wet or moist and also cold to the touch.
- In axillary hyperhidrosis, excessive sweating in the underarm area occurs, leaving large wet marks and staining clothes.
- In scalp/facial hyperhidrosis, excessive sweating of the face and scalp occurs, as well as moderate to severe facial blushing.
- In plantar hyperhidrosis, the soles of the feet sweat excessively. This condition is often associated with hyperhidrosis in other body areas.
- In truncal hyperhidrosis, the torso area sweats excessively. This condition is rare alone and usually occurs with hyperhidrosis in other areas.
When to call the doctor
Parents should call the doctor if their child or adolescent experiences excessive sweating unrelated to an obvious medical condition (e.g., high fever ) or physical exertion. Usually, consultation and treatment will be given by a dermatologist.
Hyperhidrosis is diagnosed by physical examination. For suspected secondary hyperhidrosis, laboratory and imaging tests may be performed to determine the underlying medical condition causing the hyperhidrosis.
Topical agents applied to the skin in the affected area are the first course of treatment for hyperhidrosis. Topical applications include anticholinergic drugs, boric acid, tannic acid solutions, and glutaraldehyde. Drysol, an aluminum chloride solution, is the most commonly used and most effective topical application; it is applied nightly on dry skin. Systemic medications may be taken orally and include anticholinergic drugs, sedatives or tranquilizers, and calcium channel blockers. These oral drugs do have side effects, such as dry mouth and eyes, blurry vision, and constipation , and may not be appropriate for pediatric patients.
Iontophoresis, which involves the application of an electrical current across the skin, can be used to treat plantar and palmar hyperhidrosis but requires daily treatment for about 30 minutes, often multiple times daily.
As a last resort, surgery is used to treat palmar, plantar, and axillary hyperhidrosis. Surgical procedures involve removing portions of the nerves responsible for excessive sweating and removing sweat glands during an open or minimally invasive surgical procedure. Liposuction may be used to remove sweat glands in the underarm area.
In 2004, the U.S. Food and Drug Administration approved the use of botulinum toxin (Botox) for treatment of axillary (underarm) hyperhidrosis that resists treatment with topical drugs. Botox is commonly used for cosmetic treatment of wrinkles but is also used to treat neuromuscular problems, including migraine and cervical dystonia. In the early 2000s researchers are also investigating the use of Botox to treat hyperhidrosis of the hands, feet, and face. Although most studies of Botox for hyperhidrosis included adult patients, some physicians use Botox to treat hyperhidrosis in children with some success. Even though Botox has only been approved to treat axillary hyperhidrosis, physicians can legally use Botox "off-label" to treat other affected areas of the body. Botox is injected into the affected area, and one series of injections may last for several months. Botox is a likely treatment when topical applications fail.
In 2004, guidelines were proposed by expert physicians for treating primary hyperhidrosis. Topical treatments followed by Botox if the topical agent fails is recommended for treating axillary and facial hyperhidrosis. For palmar and plantar hyperhidrosis, topical treatment and iontophoresis, followed by Botox are recommended. Surgery is mentioned as an option only for palmar and axillary hyperhidrosis and only as a last resort.
Although no evidence has documented an effective alternative treatment for hyperhidrosis, acupuncture, homeopathy, and/or herbal preparations are used by some individuals with hyperhidrosis. A common home remedy involves soaking the affected body parts in home-brewed tea, which contains tannic acid, a natural antiperspirant. Because stress can trigger sweating, relaxation techniques such as yoga , massage, and meditation can help with stress reduction.
Hyperhidrosis is not a life-threatening condition. However, it can severely affect quality of life and comfort in social situations. Children and adolescents who receive early treatment have a better quality of life. If left untreated, hyperhidrosis can result in physical, social, and occupational impairments.
Hyperhidrosis treatments help to prevent excessive sweating but may not entirely eliminate the condition. Hyperhidrosis can be managed by using simple daily personal hygiene methods, such as the following:
- bathing daily to reduce bacteria
- washing and changing clothes frequently
- changing socks or pantyhose at least twice daily
- airing out shoes and rotating shoes worn each day
- wearing absorbent socks, clothing shields, and natural fabrics
- using antiperspirants in the evening and gently massaging them into the skin
- using foot powders and going barefoot frequently to air out feet
Although no foods cause hyperhidrosis, certain foods and food ingredients can stimulate sweating and should be avoided. These include caffeine , alcohol, and spicy foods. Hot beverages, like coffee and hot chocolate, may also increase sweating. Consuming foods with strong odors, such as those containing garlic and onions, should be avoided because it can cause a person's sweat to smell stronger.
Children and adolescents with hyperhidrosis suffer extreme social embarrassment related to their condition, and hyperhidrosis can result in low self-esteem , difficulties in school, and difficulties in and avoidance of social situations. For example, children with palmar hyperhidrosis may have difficulties holding a pen to write, and adolescents may be reluctant to shake or hold hands with others. Children with axillary hyperhidrosis may be made fun of for excessive body odor and sweat stains. Early treatment is essential to improve children's quality of life. Joining a support group or participating in online hyperhidrosis chat groups may help individuals better manage their condition through peer support.
Anticholinergic drug —Drugs that block the action of the neurotransmitter acetylcholine. They are used to lessen muscle spasms in the intestines, lungs, bladder, and eye muscles.
Axillary —Located in or near the armpit.
Liposuction —A surgical technique for removing fat from under the skin by vacuum suctioning.
ABBE Research Division Staff. Sweat, Sweating, Sweat Gland Problems: Index and Analysis of New Information, Research, and Clinical Results. Washington, DC: ABBE Publishers Association of Washington, DC, 2003.
Bartone, John C., Sr. Human Sweat and Sweating, Normal and Abnormal, including Hyperhidrosis and Bromhidosis, with Index of New Information and Guidebook for Reference and Research. Washington, DC: ABBE Publishers Association of Washington, DC, 2001.
Bhakta, B. B., and S. H. Roussounnis. "Treating Childhood Hyperhidrosis with Botulinum Toxin Type A." Archives of Disease in Childhood 86 (January 2002): 68.
Hilton, Lisette. "Stopping Sweat . . . and Soon: Botulinum Toxin Effective for Pediatric Hyperhidrosis." Dermatology Times, April 1, 2003.
International Hyperhidrosis Society. 18 South 3rd Street Philadelphia, PA 19106. Web site: <www.ihhs.net/index.html>.
Altman, Rachel. "Hyperhidrosis." eMedicine, August 18, 2004. Available online at <www.emedicine.com/derm/topic893.htm> (accessed November 10, 2004).
"National Survey Finds Hyperhidrosis Affects Nearly Three Times as Many People as Previously Thought." International Hyperhidrosis Society, August 2, 2004. Available online at <www.ihhs.net/about_hhs/press10.asp> (accessed November 10, 2004).
Jennifer E. Sisk, M.A.