Anticholinergic drugs, such as Robinal, may help prevent the stimulation of the sweat glands and thus inhibit sweat output. The FDA has not approved any drug for the treatment of hyperhidrosis. Although these drugs may be effective in inhibiting excessive sweat, there are significant side effect risks with these medications. These include such effects as dry mouth, blurred vision, urine retention, constipation, impaired swallowing, taste, etc. Medications such as these are usually taken only for special occasions when sweat control is important. Most persons cannot tolerate the side effects on a daily basis (12).
Botulinum Toxin A Injections (Contributed by Zoe Diana Draelos, M. D.)
Botulinum toxin A (Botox, Allergan) is the most effective method of reducing axillary hyperhidrosis. It is classified as a method of chemodenervation, since it interrupts the nerve signal to sweat. As mentioned previously, axillary hyperhidrosis is largely under central control. The brain must send a signal to the nerves in the armpit to initiate sweating. If the nerve signal is never received by the sweat gland, sweating does not occur. This is how botulinum toxin works. Unfortunately, it cannot be applied to the skin surface, but must be injected with a small insulin syringe just beneath the skin surface where the sweat glands lie.
Botulinum toxin A treatment for hyperhidrosis is typically administered as a medical procedure in the office of a dermatologist. The armpit is first cleaned thoroughly to remove all sweat and antiperspirants. It is then painted with an iodine solution and dusted with cornstarch. The reaction between the sweat and iodine will turn the cornstarch black once perspiration has begun. An indelible marker is then used to draw a line around the area of maximum sweating. This is the location for the botulinum toxin A injections.
Once the area of maximum sweating has been determined, the botulinum toxin A is removed from the freezer, where it must be keep until just before use. The freeze-dried botulinum toxin bottle containing 100 units is then reconstituted with 2 cc of unpreserved sterile saline. Approximately 10 units are drawn up into 20 insulin syringes for injection with 10 syringes used in each armpit. The injections are made just under the skin surface to raise a tiny wheal at 2 cm intervals in a whirl configuration from the central armpit outward until the entire area outlined by the indelible marker has been injected. As might be imagined, this is a painful and tedious procedure.
Fortunately, the sweat reduction induced by the botulinum toxin A lasts for approximately six months, or longer in some individuals. The treatment does not completely eradicate axillary sweating, but significantly diminishes its amount. Any remaining sweating can usually be controlled with traditional nonprescription antiperspirants. Botulinum toxin A can also be injected into the hands and feet for purposes of sweat reduction.