Hyperhidrosis

Hyperhidrosis means excessive sweating. It can be localized or affect the whole face and body. Sweating is controlled by the brain, which sends signals along nerves called “sympathetic nerves” to the small sweat glands in the skin. 

These nerves are part of the “autonomic nervous system,” which controls many unconscious body functions. Increased sweating is a normal response to a rise in body temperature and emotions such as anxiety. 

A treatment that reduces sweating is called an antiperspirant. This treatment is different from a deodorant, which reduces odor, usually through an antibacterial effect. The two are often combined in the same product.

Localized symmetrical hyperhidrosis (primary hyperhidrosis) is the most common type of hyperhidrosis; this affects specific body sites (localized), and both sides equally (symmetrical). The palms, soles, underarm skin, face, and scalp, or a combination of these, can be affected by excessive sweating.

The cause is not known. It usually begins in childhood or adolescence and may improve with age. This type of hyperhidrosis is also called focal or primary hyperhidrosis.

Generalized hyperhidrosis (affecting the whole body) can be caused by some illnesses, including infections and hormonal conditions, including menopause, diabetes, and an overactive thyroid gland. This type of hyperhidrosis is called secondary hyperhidrosis.

Some medicines can also cause excessive sweating, including fluoxetine and similar antidepressants. Sometimes no cause can be found. Disease or irritation of the sympathetic nerves is a rare cause of increased sweating, either generally or in localized areas (typically just on one side of the face or body).

Anxiety can trigger or worsen hyperhidrosis, but this does not necessarily mean that the affected person is unusually anxious or stressed. Sometimes worry about sweating can create a vicious circle making the problem worse.

Hyperhidrosis is a feature of some rare inherited conditions. There is a trend for the common localized symmetrical type to run in families, and up to a third of people with hyperhidrosis may have a family member with the condition.

Visible sweat, wet clothes, and clammy palms can be embarrassing and interfere with work and personal relationships. Some people find hand sweating produces problems such as embarrassment when shaking hands, difficulty when writing on paper, using keyboards, playing musical instruments, and playing racquet sports. 

Hyperhidrosis affects the water-producing (“eccrine”) sweat glands and not the “apocrine” sweat glands, which produce the more oily type of sweat that causes odor, especially under the arms. Therefore, a foul odor is not a direct result of hyperhidrosis; however, if feet excessively sweat overgrowth of harmless skin, bacteria can cause an unpleasant smell.

Your doctor will assess which kind of hyperhidrosis you have. The doctor may suggest you have tests for an infection, diabetes, thyroid overactivity, or other conditions.

Most people with hyperhidrosis will have tried commercial antiperspirants. If these fail, and if the sweating is bad enough to interfere with your work or social activities, you should ask your doctor for advice. The doctor will assess whether there might be an underlying cause and may start treatment. If necessary, you may be referred to a dermatologist.

Localized hyperhidrosis

• Aluminum chloride is the usual active ingredient in commercially available antiperspirants. More vigorous preparations of aluminum chloride can be prescribed for excessive sweating and are mostly used under the arms but can be used on the hands and feet.

They should be applied at night only to dry skin. However, sore red skin is a common problem. This issue can be reduced by making sure the skin is completely dry before applying the solution, by using hydrocortisone cream to reduce the inflammation, and by using the treatment less frequently and then trying to build up.

There are now newer aluminum chloride antiperspirants that contain aloe vera and cause less sensitivity.

• Formalin solutions harden the skin and can block the tubes leading from sweat glands to the skin surface. They are suitable only for the soles of the feet and not commonly used nowadays.
• Solutions of the anticholinergic drug glycopyrrolate can reduce sweating in localized areas such as the scalp and forehead.
• Iontophoresis is a method of passing a small electric current through areas of skin immersed in a dish of water. The treatment needs to be done regularly and takes approximately 10- 20 minutes to perform. Iontophoresis does tend to cause a tingling sensation; if this causes discomfort, then the current can be reduced.

• Botulinum toxin derived from bacteria (one brand name is “Botox”) can be injected into the skin in minimal, carefully controlled doses to block the action of the nerves, which activate the sweat glands. 

This treatment usually works very well. The effect usually lasts 2-6 months, although some patients may continue to benefit for 12 months, and the treatment can be repeated.

Botulinum toxin is only licensed for underarm sweating and not for large areas. The skin can be numbed with an anesthetic cream or injection, but this is often not needed as underarm skin is not very sensitive.

Botulinum toxin is not commonly used in the palms and soles because it can cause temporary weakness of hand and foot muscles and is painful.

• MiraDry is a new treatment that uses controlled microwave technology to destroy sweat glands without surgery.
• Endoscopic thoracic sympathectomy (an operation to cut the sympathetic nerves triggered to produce sweating) may be considered for localized hyperhidrosis when other treatments have failed.
• Other surgical methods apply only to the underarm skin, especially when only a small area is involved. These include removing an area of skin containing the overactive sweat glands, or the scraping away of the sweat glands from an area of skin or from the underside of the skin through a small hole, which is then repaired. Generalized hyperhidrosis is too widespread to treat with antiperspirants, injections, or surgery.

However, some medicines, taken as tablets, can reduce sweating. The most reliable ones block the chemical signal between the nerves and the sweat glands (an anticholinergic drug).

Propantheline is the only anticholinergic drug licensed for hyperhidrosis. However, although unlicensed, other anticholinergic drugs are widely used (such as oxybutynin and glycopyrrolate). 

Unfortunately, anticholinergic drugs sometimes cause side effects, including a dry mouth, blurred vision, tummy cramps, constipation, and difficulty passing urine.

They may be harmful to people with glaucoma and some other conditions. A small dose is used at first and gradually increased. As the dose increases, some people get relief from sweating before significant side effects occur, but for others, the side effects begin before they reach an amount high enough to control sweating.

Other medications such as B blockers, clonidine, and anxiolytics may be useful for some patients.

If medical treatment is not possible or is unsuccessful, there are still several ways you can help yourself.

You should try to avoid situations which you find trigger your sweating, such as hot places or rushing about.

Alcohol and spicy foods can also bring on an episode of hyperhidrosis.

Absorbent underlayers such as cotton T-shirts (wicking fabrics) can help hyperhidrosis of the body. Adhesive absorbent underarm pads for clothing are available on the internet.

Loose-fitting clothes made of natural fibers and leather shoes/sandals are beneficial. Changes of clothes may be necessary during the day. If your feet are the main problem, you may need to change socks and shoes during the day. You may be able to slip your feet out of your shoes even for short periods. You should have several pairs of daytime shoes so that each pair has a few days to dry out. There are many good, absorbent insoles available that will also help.

It is best to avoid soap-based products and to use an emollient as a soap substitute instead. Cotton, silver, and copper socks are also helpful for many, which may work by helping to reduce sweating or to reduce odor secondary to excessive sweating.