Subcutaneous botulinum toxin type A inhibits regional sweating: an individual observation.

Botulinum toxin inhibits neuromuscular transmission by blocking the exocytosis of acetylcholine. It was tested for a similar effect on cholinergic postganglionic sympathetic neurones at the sudomotor junction. Subcutaneous injections of 0.1 and 1.0 units of type A botulinum toxin into the forearm of a healthy subject abolished local thermoregulatory sweating in cutaneous regions spanning 1.0 and 1.5 cm for nearly 1 year without producing weakness. Botulinum toxin, therefore appears to have potent anhidrotic activity.