Botox® has been used to treat hyperhidrosis in various parts of the body with variable success. Botox® (botulism toxin) is derived from the spore forming bacillus Clostridia Botulinum. It works by blocking the neurotransmitter acetylcholine which is secreted by the sympathetic nerves in proximity to the sweat glands that reside in the skin. Acetylcholine binds to a receptor on the sweat gland which is than stimulated to produce sweat, that travels along the sweat ducts, through pores onto the surface of the skin. Botox® will irreversibly binds to these receptors, and prevents activation of the sweat glands by acetylcholine. Over several months, Botox® gradually degrades, and sweating returns unless the treatments are repeated.
We do not generally recommend Botox® therapy for the treatment of palmar hyperhidrosis for several reasons. It is rather painful, and success rates even when performed by skilled technicians is only 50% at best, with the results gradually dissipating and disappearing within about 3 months. Botox® therapy is sometimes covered through health insurance, but often not. The cost of Botox® for palmar hyperhidrosis is about $1500, for 100 units. On occasion I encounter an individual with palmar hyperhidrosis who wishes to have dry hands for a once in a lifetime special occasion, and otherwise their hyperhidrosis is tolerable to them. In that rare situation Botox® therapy is a reasonable therapy.
Botox® therapy for plantar hyperhidrosis is extremely painful because of the sensitivity of skin on the soles of the feet. A regional nerve block is required to be able to effectively inject sufficient quantities of Botox® into the feet, and the results are very temporary, as such I do not feel Botox® is a useful option for plantar hyperhidrosis
Botox® was our treatment of choice for axillary hyperhidrosis prior to MiraDry® becoming available. Botox® therapy for axillary hyperhidrosis is very effective, with success rates in excess of 90%. Because the skin of the armpit is less sensitive than either the skin of the hands or feet, anesthesia is not required to inject Botox® in the armpits. After injecting 50 units of Botox® into each armpit, the results often last for up to six months. Even though Botox® does effectively reduce armpit sweating, we don’t believe it is practical compared with MiraDry® therapy, which for about the cost of two Botox® sessions, provides extreme reduction in armpit sweating. We therefore feel that MiraDry® is the treatment of choice for people with severe armpit sweating who don’t achieve adequate relief from Aluminum chloride products.
Facial sweating is a most difficult problem to treat. It often affects people with generalized hyperhidrosis, and those of menopausal age. Topical aluminum chloride is usually recommended as the first line of treatment, if ineffective than Botox® is the next best choice.
When Botox® is used on the face, hands or feet, a common side effect is weakness of the small muscles in the area, for instance when used on the hands it could result in weakness of grip strength. Similarly the muscles of facial expression can be effected when used to treat facial sweating. These side effects disappear when the Botox® degrades. Other possible side effects include allergic reactions to the toxin.