Indications

Profuse sweating of the feet.

Anatomic Considerations

Neurotoxins act by preventing release of acetylcholine from nerve endings at the neuromuscular junction, the effect of which is to inhibit muscle contraction. Acetylcholine is also the neurotransmitter for the sweat glands. Injection of botulinum toxin into sweat glands will prevent sweating and is an excellent treatment for patients who complain of profuse sweating of the feet.

Injection Technique

This is a painful procedure, and sedation or general anesthesia is usually required. Because of the increased thickness of the skin, topical anesthetics may not be well absorbed by callused feet. Using a regional block (posterior tibial and sural nerve block) or even sedation anesthesia may be necessary.

Usually 100 BU or 300 DU is injected for this treatment, divided evenly for each foot (occasionally more is necessary for larger feet). The product is injected into the dermis in small wheals separated by 1.0 to 1.5 cm. Each injection is 0.05 to 0.1 mL, or approximately 1 to 2 BU or 3 to 6 DU per injection. Because of the thickness of the skin, a 30-or 26-gauge needle may be necessary.