underarm sweating

What causes underarm sweating?

Hyperhidrosis is the medical term for excessive sweating and when it occurs in the underarm skin it is called "axillary hyperhidrosis." This is caused by stimulation of the eccine sweat glands by the nerve endings which are the final nerve pathways from higher centres in the brain. These nerves respond to different kinds of stress: emotional stress like intimate social situations or public speaking, or physical stress like the increased body temperature that comes with exercise or hot and humid weather.

Some people are routinely troubled by excessive sweating whilst others are only bothered when they are under emotional stress, physically active or over-heated. The nerves that control sweating depend upon a chemical transmitter called acetylcholine which is a molecule produced at the very ends of the nerve fibres. Botox is a genetically engineered neurotoxin which can, when injected into the skin, block the release of the acetylcholine to the sweat glands for months!

Who are good candidates for Botox?

• People with problem underarm sweating
• Those working close to others such as hairstylists, nurses, dentists and hygienists, airline flight attendants, pilots and surgeons
• People working in hot conditions such as models, television newscasters and chefs
• People making public presentations such as executives, lawyers and salesmen
• People who have ruined their clothes on special occasions such as weddings

What are the alternative treatments?

Topical antiperspirant sticks, creams, lotions and solutions typically use aluminium chloride hexahydrate salts which coat the skin and prevent the sweat from exiting the pores of the skin. They are highly irritating with continued use and largely ineffective for people with excessive sweating.

Anti-cholingeric drugs & tranquilizers currently used cause dry mouth, blurred vision and minimally reduce sweating. Tranquilizers may minimize your anxiety over sweating, but rarely diminish the excessive perspiration.

Iontophoresis using various battery powered electrical devices has been tried over the years by applying a tap water-moistened pad and electrical current held against the axillary skin for several hours. This decreases the sweating but is very time consuming, needs to be repeated on a daily or weekly basis and is only mildly effective for severe cases.

Surgery may involve cutting out the skin of the underarms containing the sweat glands and may result in very visible scars and permanent numbness of the skin. Neuro- surgeons use a fiberoptic surgical tube inserted into the neck to cut the nerve fibers leading to the axillary sweat glands and arms (endoscopic sympathectomy). This approach involves the risks associated with general of anaesthesia and possible nerve damage to structures in the neck which can result in paralysis, loss of sensation and even permanent dilation of the pupil of the eye as a reflex injury. Cosmetic surgeons have also attempted to scrape the underside of the axillary skin with liposuction cannulae to remove the sweat glands. Results have been mixed.

How is BOTOX used?

After performing a harmless and painless starch test to locate the sweat glands, a very small needle is used to inject small amounts of Botox into the skin of the underarms in approximately 12 to15 places on each underarm. Heavy physical exercise should be avoided for several hours, but patients may engage in any normal activity.

When will treatment take effect?

Your underarm sweating will decrease to 95% within 48 hours and the full effect will be seen within 1 week. Along with the sweating, there is a simultaneous disappearance of odour associated with the decreased sweating.

How long does BOTOX treatment last?

Most patients will obtain 5-6 months of dryness with one treatment of Botox®.

What are the risks and complications?

The only complications from injection into the axillary skin are some tiny bruises that are occasionally seen which fade in a few days and occasionally small persistent areas of sweating that may need a second treatment session. There is no risk of muscle weakness, numbness or permanent change in the axillary skin.