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.
— Bacterial breakdown of sweat and cellular debris resulting in a foul odor.
— Skin inflammation that occurs when the skin is exposed to a substance originating outside of the body.
— Of spontaneous origin or unknown cause. Many cases of hyperhidrosis are idiopathic.
— 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.
— Fungal infection of the feet of the skin characterized by dry, scaly lesions.
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