Primary (idiopathic) focal hyperhidrosis

This means that excessive sweating occurs in one or more of the following ‘focal’ places: palms of the hands; soles of the feet; armpits (axillae); face/scalp.

You sweat normally on the rest of the body. It tends to be symmetrical, that is, both palms, both feet, both armpits, etc, are affected. The exact cause is not known and it is not associated with any other conditions. (The word idiopathic means ‘of unknown cause’.) It just seems that the sweat glands in these areas are ‘overactive’ or more sensitive than normal. In some people, it may ‘run in the family’ so there may be some genetic factor involved in causing it. It usually first develops under the age of 25, but it can develop at any age. Men and women are equally affected. It is common and affects about 3 in 100 people.

The severity can vary from time to time. It may ‘come and go’ and can be made worse by ‘triggers’ such as anxiety, emotion, spicy foods, and heat. Anxiety about the sweating itself may make it worse. However, for most of the time, nothing obvious triggers the sweating. It tends to be a long-term condition, but symptoms improve in some cases over time.

If you have the typical symptoms of primary focal hyperhidrosis, you usually do not need any tests. Your doctor may suggest one or more treatments (below) if ‘normal’ antiperspirants do not work well.

Secondary focal hyperhidrosis

This is uncommon. It means that the excessive sweating occurs in a particular ‘focal’ part of the body. But, unlike primary focal hyperhidrosis, there is a known or likely cause. For example, a spinal disease or injury may cause sweating in one leg. Any focal sweating that is not symmetrical (that is, just in one hand, or one leg, etc) may suggest a secondary cause rather than primary focal hyperhidrosis which is usually symmetrical. Your doctor may suggest some tests to look for an underlying cause if one is suspected.

Generalised hyperhidrosis

This means that you sweat more than normal ‘all over’. This is less common than primary focal hyperhidrosis. However, it is usually caused by an underlying medical condition. A whole range of conditions can cause a generalised increased sweating. For example: anxiety disorders, various heart problems, damage to nerves in the spinal cord, side-effect to certain drugs, various hormone problems including an overactive thyroid gland, infections, certain cancers, etc. If you have Generalised hyperhidrosis your doctor is likely to examine you and do some tests to find out the cause. Treatment depends on the cause.

The rest of this leaflet is only about primary focal hyperhidrosis.

What are the possible complications of primary focal hyperhidrosis?

Although not a medically serious condition, excessive sweating can be distressing and embarrassing. For example, if you have bad palm sweating you tend to have a ‘cold, sweaty handshake’ and sweat may drip from your hands onto work documents, onto computer keyboards, etc. If you have bad armpit sweating, you may become embarrassed by the frequent ‘wet-patch’ that develops on clothes under your arms. You may need to change clothes during the day. You may avoid social contact or avoid doing sports because of embarrassment about the condition.

Other complications are uncommon. In some cases, the affected skin can become sore, irritated and prone to infection. There is a risk of developing eczema on affected skin.

Initial treatment options for primary focal hyperhidrosis

General tips and advice

The following may be all that you need if the condition is mild. They may help in addition to other treatments in more severe cases.

• If you find that soaps irritate the affected skin, use a bland soap substitute such as an emollient (moisturiser) ointment or cream.
• If possible, avoid triggers which can make things worse such as heat or spicy food.
• If you have armpit sweating:
  • Try using ‘normal’ antiperspirants regularly. (Note: there is a difference between antiperspirants and deodorants. Antiperspirants reduce the release of sweat, deodorants mask unpleasant smells. Sweat does not have a smell. It is only sweaty clothes that are not changed that may become smelly.)
  • Avoid clothes that more easily show up sweat marks. As a rule, white and black coloured clothes are less noticeable when wet than other colours.
  • Wear loose clothing under the armpits. Avoid clothes made with man-made fibres such as Lycra® and nylon.
  • Consider using dress shields (also known as armpit or sweat shields) to absorb excess sweat and protect delicate or expensive clothing. These can be obtained via the internet or the Hyperhidrosis Support Group (contact details below).
• If you have excessive feet sweating, it can help to:
  • Change your socks at least twice a day.
  • Use an absorbent foot powder twice daily.
  • Wear a different pair of shoes on alternate days. This allows them to dry fully.
  • Avoid sport shoes or boots. These are often less ‘breathable’ than normal shoes are so are more likely to keep the sweat in.

Aluminium chloride - a strong antiperspirant

If normal antiperspirants do not work, your doctor may advise an antiperspirant that contains aluminium chloride. This is a ’strong’ antiperspirant. It is thought to work by blocking the openings of the sweat ducts. It tends to work best in the armpits. However, it may also work for sweating of the palms and soles. Although it may also work on the face, some doctors do not recommend using this on the face as it may cause severe eye irritation if it gets into an eye.

There are several brands of aluminium chloride based antiperspirants. For example: Driclor® and Anhydrol Forte® come in a bottle with a roll-on applicator. ZeaSORB® is a dusting powder that contains aluminium chloride. You can buy these at pharmacies. Some are also available on prescription. It is important to use aluminium chloride based antiperspirants correctly. Read the instructions that come with the product you use. These usually include the following:

• Apply to clean, dry skin. (It is more likely to cause irritation on wet or moist skin.) Therefore, wipe the skin dry with a towel or dry flannel before applying. Some people use a hair dryer to make sure the skin is dry before applying.
• Ideally, apply at night (bedtime) when the sweat glands are less likely to be as active.
• Wash it off the next morning.
• Do not shave the area 24 hours before or after use.
• Avoid getting it in the eyes, and do not apply on broken or inflamed skin.
• Some doctors do not recommend that you apply this treatment to your face.
• Apply every 24-48 hours until the condition improves. Then apply once every 1-3 weeks, depending on response. (It may take a few weeks to build up its effect. This is because it is thought to gradually clog up the sweat gland which causes a gradual reduction in sweating.)
• If successful, treatment can be continued indefinitely. You may only need to apply it once every 1-3 weeks to keep the sweating under control.

Note: aluminium chloride antiperspirants often cause skin irritation or inflammation. If this occurs, it is often still worth persevering if the irritation is tolerable as the benefit may outweigh the irritation. To reduce the effects of any skin irritation or inflammation that may occur:

• Reduce frequency of use, and/or
• Apply an emollient (moisturiser) every day after applying the aluminium chloride, and/or
• Apply a short course of a mild steroid cream such as hydrocortisone 1% to the affected area twice daily for a maximum of 14 days. (Steroid creams reduce inflammation.)

Other treatments for primary focal hyperhidrosis

If the above general measures and antiperspirant treatments do not work, your doctor may suggest that they refer you to see a dermatologist (a skin specialist). The specialist may suggest one of the following treatments.

Iontophoresis

This is a treatment that uses electrical stimulation. It is used mainly to treat sweating of the palms and/or soles. It can also be used to treat armpit sweating. It works well in most cases. Treatment involves putting the affected areas (usually hands and/or feet) into a small container filled with water. A small electrical current is then passed through the water from a special machine. It is not dangerous, but may cause some discomfort or a ‘pins and needles’ feeling. The exact way this helps to treat sweating is not known. It may help to block the sweat glands in some way.

You will usually need 3-4 treatment sessions per week. Each treatment session lasts 20-40 minutes. Most people see an improvement after 6-10 sessions. A maintenance treatment is then usually required once every 1-4 weeks to keep symptoms away. If the treatment does not work with tap water, a drug called glycopyrronium bromide is sometimes added to the water. This may improve the rate of success. However, iontophoresis does not work in every case. Also, some people develop side-effects from the treatment such as a dry or sore mouth and throat, and dizziness, for up to 24 hours after each treatment episode.

Until recently the ‘downside’ to iontophoresis was that it required a trip to hospital for each treatment session. This can be time-consuming and impractical for some. However, modern machines are smaller and can now be bought for home use. So, if you find that this treatment works for you, you may wish to consider buying a machine to use at home. However, you should take advice from the specialist who recommended iontophoresis for you before you buy a machine.

You should not have iontophoresis if you are pregnant, or have a metal implant (such as a pin to fix a fracture), or if you have a pacemaker.

Botulinum toxin injections

This is an option that usually works well for armpit sweating. Treatment consists of many small injections just under the skin in the affected areas. The botulinum toxin stops the nerves in the skin that control the sweat glands from working. Botulinum toxin is not licensed to treat sweating of the palms and face. This is because there is a risk that the injections may stop some of the nearby small muscles of the hands or face from working.

The downside of botulinum toxin is that the effect usually wears off after 4-12 months. Therefore, to keep working, the treatment needs repeating when the effect wears off.

Some people get mild ‘flu like’ symptoms for a day or so after treatment. Also, the sites of the injections can be sore for a few days after treatment. Rarely, a severe allergic reaction can occur after an injection. It is also very expensive and not usually available on the NHS.

Medication

Drugs that block the effect of the nerves that stimulate the sweat glands are sometimes used. For example, propantheline bromide. These drugs are not used very often. This is because the success of these drugs is variable. Also, side-effects commonly occur. For example, a dry mouth and blurred vision. However, for some people they work well and side-effects are minor.

Surgery

An operation is an option for people who have not been helped much by other treatments, or if other treatments cause unacceptable side effects or problems.

For armpit sweating - an option is to remove the sweat glands in the armpit. There are various techniques. For example, one operation is to cut out the area of skin in the armpit that contains the sweat glands. This usually works to reduce sweating, but a number of people have had problems after this operation due to scarring and a loss of the full range of movement of the arm. A newer technique is to ’scrape’ the sweat glands from the under side of the skin through a small hole cut in the skin. This appears to give good results with less risk of complications. A recent innovation has been to use a laser to destroy the sweat glands in the armpit - laser sweat ablation (LSA). This may result in less scarring than other surgical techniques.

For palm sweating - an option is to have an operation to cut some of the nerves that run down the side of the spinal cord. These nerves control the sweat glands in the hands. The operation is called a ‘ thorascopic sympathectomy’. It is done by ‘key-hole’ surgery using a special telescope to locate the nerve, and then to cut the nerve. Most people are pleased with the result of the operation. However, a complication that often occurs following this operation is a compensatory increase in sweating in other parts of the body (such as in the chest or groin). This can be worse than the original problem in the hands. Because of this effect, a number of people who have this operation say that they regret having it done.

Before you undergo surgery, you should have a full discussion with the surgeon. He or she will explain the pros and cons of the different surgical techniques, chance of success (usually high), and possible risks and complications. For example, as with any other type of surgery, there is a small risk from the anaesthetic. Also, wound infection and damage to other nearby structures, although uncommon, are other possible complications.

Surgery is not usually done for sweating of the soles. Although cutting the nerves next to the spinal cord in the lower back region may cure the problem of sweating, there is a high risk of this also affecting sexual function.