Hyperhidrosis – Excessive Sweating

Controlling either axillary perspiration or generalized sweating can be embarrassing for the person afflicted and can be challenging for the dermatologist to treat. The challenge is even greater when the sweating is related to anxiety. Generalized sweating can be related to internal disease but we will concentrate our discussion on increased sweating involving the armpits, palms, and soles.

Perspiration helps make for a good medium for bacterial growth: this is the cause of the axillary odor associated with sweating. There are many methods to control perspiration, but the first method to be used is topical therapy.

The words “antiperspirant” and “deodorant” are sometimes used interchangeably in the common vernacular but they are two different personal care products. Antiperspirants contain ingredients to decrease sweating, while deodorants are used solely to manage axillary odor.

Topical antiperspirants reduce axillary moisture by employing aluminum salts to create a plug within the sweat gland located in the skin. It takes about ten days to create the plug, which physically blocks the transport of sweat from the gland onto the skin surface. Thus, antiperspirants should be applied daily, and good results won’t necessarily be apparent in less than a week. The plug tends to wash away with heavy sweating, so nighttime application is usually more efficacious: dryer skin allows more contact between the antiperspirant and the skin and the plug has more time to form.

Of the varying types, aerosols are less effective than roll-ons. To be considered efficacious, an antiperspirant must reduce axillary sweating by at least 20%. To claim membership in a newer category, “clinical strength” products must reduce sweating by at least 30%, and twice daily usage is recommended.

For those patients who can’t reduce their sweating enough with antiperspirants, there are other measures that doctors may recommend to try to eliminate heavier sweating. Some of these measures involve non-aluminum based antiperspirants, prescription strength medications, oral medications for those who have wider involved skin areas of sweating, and, ultimately, botulinum toxin injections which can arrest axillary sweating for periods of 3-12 months.

Botulinum toxin’s mechanism of action regarding sweating is not entirely understood, but is thought to involve blocking the release of a neurotransmitter (acetylcholine). Some our happiest patients are those that have had botulinum toxin injections for relief of hyperhidrosis. They are suddenly able to change their wardrobe from black shirts to yellows and pinks and don’t need to change their clothing as often. Botulinum toxin can also be injected into palms and soles if topical agents fail in these areas.

Oral medications can be prescribed if the sweating is generalized, but there are side-effects associated with their use. These are reserved for those patients where benefits outweigh the risks. Surgical intervention is a last resort and is considered when all of the above measures have failed and the sweating is debilitating.

Tips for control of perspiration:

  • Apply antiperspirants to dry armpits. The antiperspirant must remain in physical contact with the armpit to create a plug. Careful use of a hair dryer before application may be necessary.
  • Do not shave aggressively. This minimizes the chance of removing the sweat duct plug.
  • Apply the recommended amount of antiperspirant to obtain optimal efficacy.
  • Apply topical antiperspirant daily. As with any topical dermatologic treatment, if you don’t use it, it doesn’t work. Daily application is necessary, and twice daily application is even better. Consecutive application for ten days may be necessary for the formulation to be effective.