When sweating becomes a burden
Sweating is an important bodily function: it regulates temperature and protects against overheating. Some people, however, sweat noticeably more than is necessary for thermoregulation – even at rest, in cool temperatures or without any recognisable trigger. In such cases, doctors speak of hyperhidrosis, an excessive production of sweat. The underarms, palms, soles of the feet and the face are particularly often affected.
For many of those affected, this means a considerable restriction in daily life and social interactions: soaked clothing, slippery hands when shaking hands, difficulties holding pens or tools. Over recent years, hyperhidrosis treatment with botulinum toxin type A has become established as a complementary procedure that can contribute to symptom relief in many cases.
What is hyperhidrosis?
Doctors distinguish two main forms:
- Primary (idiopathic) hyperhidrosis: This occurs without an identifiable underlying condition, often starts in adolescence and usually affects specific body areas such as the underarms, hands or feet.
- Secondary hyperhidrosis: This results from another condition (e.g. an overactive thyroid, diabetes, hormonal changes) or as a side effect of medication. In this case, treating the underlying cause is the priority.
A medical assessment is therefore important before considering symptomatic therapy such as botulinum toxin.
How does botulinum toxin work in hyperhidrosis?
Botulinum toxin type A is a protein that temporarily inhibits the transmission of nerve impulses at certain nerve endings. In the treatment of excessive sweating, this effect is used to block the signals to the sweat glands. As a result, less sweat is produced in the treated area.
Important: the sweat glands themselves are not destroyed. The active substance acts locally and is fully broken down after a few months.
Areas of application
Treatment with botulinum toxin for hyperhidrosis is used primarily in the following body areas:
- Underarms (axillary hyperhidrosis): the most common indication, as application is well established here and is usually well tolerated.
- Palms (palmar hyperhidrosis): can ease everyday life, for example in professions involving frequent hand contact.
- Soles of the feet (plantar hyperhidrosis): possible, but technically more demanding.
- Forehead and face: in selected cases, with particular care due to the facial muscles involved.
How the treatment is carried out
Before the therapy
A detailed medical consultation takes place before injection. Possible causes are clarified, previous therapies discussed and individual expectations addressed. In some cases, a simple test (e.g. the Minor iodine-starch test) is performed to visualise the area with the most pronounced sweat production.
Points to clarify include:
- existing pre-existing conditions (e.g. neuromuscular disorders)
- current medication use
- pregnancy or breastfeeding
- known allergies or intolerances
The injection
The active substance is introduced superficially into the skin of the affected area in several small doses using a very fine needle. In the underarms, the treatment is generally well tolerated. The skin on the hands and feet is more sensitive; here, additional surface anaesthetic measures, cooling or special techniques are often used.
The actual treatment usually takes 20 to 40 minutes. Afterwards, normal daily activities can typically be resumed straight away.
Onset and duration of effect
- A noticeable reduction in sweating usually sets in after a few days up to two weeks.
- The effect lasts for varying lengths of time, often between four and seven months.
- The treatment can then be repeated.
Possible side effects and risks
As with any medical procedure, unwanted effects are possible. These include:
- temporary redness, small bruises or tenderness at the injection sites
- rarely, mild muscle weakness in adjacent areas, particularly with treatments on the hands
- headaches or a feeling of fatigue in the first few days
- in isolated cases, altered sweating behaviour in other parts of the body (compensatory sweating)
The extent to which the therapy is suitable and which risks apply in the individual case is clarified during the medical consultation.
Underarm sweating therapy: what alternatives are there?
Botulinum toxin is one of several options. Depending on the severity and location, the following measures may also be considered:
- Antiperspirants containing aluminium chloride: as basic therapy, particularly for mild to moderate hyperhidrosis.
- Iontophoresis: a weak direct current applied in a water bath, often used for hands and feet.
- Oral medication: in certain situations, but often with systemic side effects.
- Surgical procedures: such as curettage or suction curettage of the underarm sweat glands; usually considered only when other therapies are insufficient.
- Microwave or laser therapy: available in specialised centres.
Which method is suitable depends on the location, the severity, lifestyle factors and individual pre-existing conditions.
Who is the treatment suitable for?
Injection therapy with botulinum toxin can be considered when:
- there is a marked hyperhidrosis that is distressing in everyday life,
- conservative measures such as specific antiperspirants have not had a sufficient effect,
- there are no medical reasons against its use.
The therapy is not suitable, among other situations, in certain neuromuscular disorders, during pregnancy and breastfeeding, and in cases of known hypersensitivity to ingredients of the preparation.
What to consider before your appointment
- Make a note of the situations in which sweating is particularly severe.
- Bring a list of your current medications.
- Think about which therapies you have already tried and how they worked.
- Plan for a quiet day after the treatment and, in line with medical advice, avoid sauna visits, intense physical exertion or direct sunlight for a short period.
Conclusion
Excessive sweating is more than a cosmetic concern – it can significantly impair quality of life. Treatment with botulinum toxin type A represents an established complementary option that can contribute to easing symptoms. A careful medical assessment of the causes and an individual treatment plan are prerequisites for finding the appropriate approach.
This article does not replace medical advice.