Generalised hyperhidrosis affects the whole body and is rarer. Focal hyperhidrosis is more common: underarm sweating accounts for about 30% of complaints, followed by the hands and feet; the face can also be affected.
The causes are not fully known and a genetic tendency is generally accepted. Contributing factors include stress, certain medicines, an overactive thyroid, adrenal disorders, menopause, low blood sugar, obesity, some cancer drugs and hormones, psychological factors, systemic diseases, diabetes, heart failure and carcinoid syndrome. In practice the most common form is stress-related; complaints persist all year and usually begin in adolescence.
What can be done for hyperhidrosis
- Choose clothing that keeps you cool, prefer natural fabrics and change clothes during the day.
- Keep the working environment cool and well ventilated.
- Avoid food and drink that trigger sweating (very spicy or acidic food and drinks).
- Odour can be managed with careful personal hygiene and suitable products.
Treatment options
- Antiperspirants act briefly. Iontophoresis can be used for the hands and feet, but it must be applied at least twice a week and the effect is not lasting, so success and adherence are low.
- Surgical removal of the sweat glands is possible for the underarm area, but it is demanding for most patients and can cause secondary problems.
Botox for hyperhidrosis
Botulinum toxin injected under the skin temporarily blocks the nerves that reach the sweat glands, so sweat production in that area stops. It affects only the sweat glands, not sensation.
How is it applied?
Very fine needles are used at close intervals over the sweating area. A colouring solution can be applied to show where sweating is most intense. The application takes at most half an hour, and a local anaesthetic cream is usually used to keep it painless. Daily activities can be resumed immediately.
When does it start to work and how long does it last?
Improvement is seen within the first week. The effect usually lasts 6 to 10 months; a second application is made when it begins to wear off.
What happens if the applications are not continued?
The effect wears off gradually. Without further applications there is no permanent change in the treated area, and sweating slowly returns to its previous level.