Hyperhidrosis Health Article

Definition

Hyperhidrosis is a medical condition characterized by excessive sweating in the armpits, palms, soles of the feet, face, scalp, and/or torso.

Description

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.

Demographics

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.

Diagnosis

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.

Treatment

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.