EXCESSIVE SWEATING (BOTULINUM TOXIN)
Hyperhidrosis means excessive sweating in the armpits. Sweating is one of the most important ways in which the body loses heat; however, people with hyperhidrosis produce sweat in amounts far greater than needed to control their temperature.
There are two main types of hyperhidrosis:
- Focal hyperhidrosis is the more common type involving excessive sweating on the feet, hands and, in about 30 – 40% of cases, the armpits. The face may also be affected, but less often. Even less common is gustatory hyperhidrosis, when sweating on the face is triggered by hot or spicy food. Botox® is recommended for the treatment of focal hyperhidrosis affecting the armpits (axillary hyperhidrosis) when other treatments have not worked.
- Generalised hyperhidrosis affects the whole body. It is much less common and is usually caused by another illness such as an infection, diabetes or when the thyroid gland is overactive. The excessive sweating usually stops when the illness is treated.
It has been estimated that up to 1% of the population has some form of hyperhidrosis. It usually starts during the teens and twenties.
It is not known why some people are affected and others are not. About ⅓ to ½ of people with hyperhidrosis have a relative with a similar problem, suggesting that there may be a genetic cause.
Hyperhidrosis is caused by overactivity of one type of sweat gland, the eccrine gland. These glands are found virtually all over the body surface but they are concentrated on the palms of the hands, the soles of the feet and in the armpits.
Many things can trigger normal sweating and this is also true for hyperhidrosis – it is just the amount of sweating that varies.
Examples of triggers include:
- Heat or cold
- Alcohol, coffee or tea, smoking, hot or spicy food
- Stress, anxiety or strong emotions
- Certain times of the day
People with hyperhidrosis can produce a large volume of sweat. This means that the hands, feet, chest or armpits (depending on which part of the body is affected) may be constantly damp. This may make normal everyday activities more difficult to carry out and it can cause embarrassment at work or socially. However, it is not true that hyperhidrosis causes body odour: the smell that some people think is due to sweating is in fact caused by bacteria if sweat remains there for a long time.
Simple self-help measures you can take include:
- Choose clothing that will keep you cool.
- Keep your work environment cool and well aired.
- Avoid the food and drinks that trigger sweating.
- Reduce stress, tension and anxiety.
- Pay attention to your personal hygiene.
Botox® is a treatment given by injection into the skin. It is recommended for the treatment of hyperhydrosis and it has also been used for many years to treat muscle spasm affecting the eyes, face and neck. Botox® is also used to relieve muscle spasm in children with cerebral palsy.
Botox® is a very pure preparation of a protein, botulinum toxin type A, obtained from the bacteria Clostridium botulinum grown under modern methods of cultivation. When small doses are injected into the skin, Botox® blocks the actions of the nerves that supply the eccrine glands; this prevents the glands from producing sweat. Botox® blocks the nerve endings but over about 6 – 12 weeks new nerve endings grow to replace them. This means that the effects of treatment last for several months but eventually they will wear off.
Using a very fine needle, your doctor will inject a small amount (0.1 ml – 0.2 ml) of a solution of Botox® into 10 to 15 places about 1cm apart and spread evenly in each armpit. Sometimes a dye is used to show up the areas where sweating is greatest and where the injections should be placed. A course of treatment takes about 30 minutes.
The needles used are very fine so most people experience only mild discomfort. It is unknown for pain relief to be required.
You should notice some change for the better within a week of your treatment.
Different people have different responses to treatment. In a clinical trial, sweat production was reduced by 83% one week after treatment. Furthermore, sweating was reduced by at least half in 95% of patients. Your next treatment can be given when the effects of the first course wear off, this usually happens after 8 to 9 months.
The doctor will advise you about when to return for further treatment.
The effects of Botox® wear off over a period of several months. If you decide not to have any further treatment there will be no lasting change in the areas treated. Sweating will gradually return to the level it was before you started treatment.
Every treatment has side effects in at least some patients. In clinical trials of the treatment of axillary hyperhidrosis with Botox®, 11% of patients reported a side effect. About 4,5% of patients experienced an increase in sweating in another part of the body.
Since the injection is made only into the skin, the effects of Botox® will be limited to the nerves supplying the sweat glands. Occasionally, a very small amount of Botox® may spread out from the injection site and affect a nearby nerve that supplies a muscle. In clinical trials, about 0.7% of patients experienced mild weakness of the arms; this did not last and got better without any treatment.
Because Botox® is a protein, there is a small chance that “flu-like” symptoms (tiredness, mild fever, muscle aches) may occur, these will disappear within a few days. You may also feel a little discomfort at the injection sites.
If any of these effects become troublesome or you notice other effects you think might be caused by your treatment, consult the doctor.
You should not have Botox® if you have certain conditions and there are circumstances when you need to take special care. You should tell your doctor:
- If you think you may be allergic to Botox® or anything in the preparation
- If you are pregnant, thinking about becoming pregnant, or you are breast feeding
- If you suffer from any muscle problems
- If you are using any antibiotics or drugs to relax muscles
- If you have any condition or you are taking any medicine that affects blood clotting, for example aspirin
- If you have had any problems with Botox® treatment in the past
- If you are taking any medicines, including any that have not been prescribed by your doctor
- If you have had some types of surgery to your armpits
- You must avoid becoming pregnant, so make sure that you use effective contraception
- You must not breast feed during treatment
- You should not be treated with certain antibiotics or drugs that relax muscles
- Check with your doctor or pharmacist if you need to take any medication and tell them you are being treated with Botox®
- If you find that your arms are affected, for instance if they feel weak, this may impair your ability to drive or use machinery so avoid doing so until you feel better.
- A pregnant patient will not be injected with Botox®