Botulinum Toxin for Hyperhidrosis

One unusual area where botulinum toxin has an effect is the sweat glands. In the same way that the toxin prevents nerves stimulating muscle contraction, the nerves stimulating sweat production are also blocked. What this means in practice is that skin injected with the toxin will not sweat in response to nervous stimulation, though the response to heat is unaffected.

Some people have an unusually high sweat production in certain areas and this becomes even more pronounced when under stress. This can prove a considerable social disability, and when it affects the hands can cause the individual problems with holding and manipulating objects. Some find that they drop things because their hands are constantly wet, and they may have difficulty writing.

Existing treatments are often very unsatisfactory, being either ineffective, time consuming, or, in the case of surgery, not without significant risk. Botulinum toxin is a highly effective treatment with an effect that lasts up to nine months, when it can be repeated.

The first step in treatment is to identify the area of skin containing the overactive glands. This is done with a simple and painless application of iodine and starch. Once the area is identified multiple injections are made with a very fine needle directly into the skin. If the armpits are being treated these injections can usually be tolerated, but if not, an application of local anaesthetic cream can be applied beforehand. When treating the palms of the hands or the soles of the feet the areas are numbed by local anaesthetic injections into the wrists or ankles. The procedure takes 20 to 30 minutes. The starch iodine test is often repeated 4 weeks later to identify and treat any missed areas, if required.