Symptoms of palmar and plantar hyperhidrosis can be reduced by treatment with botulinum neurotoxin, though it is crucial to effectively manage pain during injection, according to an article published in the journal Dermatologic Clinics (Oct. 2014; 32(4):505–515).
“The hands are extremely sensitive,” said Dr. Nowell Solish, an assistant professor at the University of Toronto and an author of the paper. “If you are injecting [botulinum neurotoxin]
into the face you are putting it into an area with a lot less nerves and the skin is a lot looser and softer. When you put it into the hand it is very thick skin, tight skin, and there are a lot of nerve endings so it can be very uncomfortable.”
Use ice to numb the injection site Dr. Solish’s technique, which he recommends as an efficient and effective approach, is to use ice with gauze frozen around it. He places a towel under the patient’s hand or foot to catch the dripping and then puts the ice on the spot where he will inject.
The ice is held in place for 10 seconds
He then moves the ice to the next site of injection and while holding it there he makes the initial injection. He repeats this technique with the following injections. This makes the procedure very tolerable.
Another pearl from Dr. Solish is to use a BD insulin syringe. He says because this syringe has a small, sharp needle it is easier to inject under pressure, which is required to inject into the hands and feet.
This approach “is usually a little time consuming but it is usually very effective, both from a pain point of view and to get the drug where you want it,” said Dr. Solish.
Nerve blocks accomplished through injection of anesthesia is not as desirable in palmar and plantar hyperhidrosis cases, said Dr. Solish, because the hands and feet remain frozen for hours. Patients are unable to use their hands for important tasks such as driving.
Botulinum neurotoxin is an effective treatment for palmar hyperhidrosis in about 80 to 85% of patients, according to Dr. Solish, compared to a 99% efficacy rating for axillary hyperhidrosis.
Usually the treatment needs to be repeated every six months in the hands and feet and up to seven months for the underarms, he said.
Other treatment options There are al so other methods for treating palmar and plantar hyperhidrosis such as utilizing an iontophoresis machine. The machine sends an electric current through the water and will result in a plug in the sweat glands.
The procedure is usually done three times a week and each session is about 20 to 30 minutes in length. Dr. Solish said this therapy is effective for about 80% of palmar or plantar hyperhidrosis patients. For the clinician, the machine is a one time cost, and has no consumables.
Surgery is another option, said Dr. Solish, although it carries a high risk. A high percentage of patients who undergo surgery develop compensatory sweating, which is irreversible.
“I do not recommend the surgery very often, unless we have tried everything and nothing works and they want to go for it. The results are permanent, but so are the side effects.”
Need greater awareness of condition Dermatologists are becoming more aware of palmar and plantar hyperhidrosis treatment options—including botulinum neurotoxin. Awareness, however, among primary care physicians and patients is still limited, noted Dr. Solish.
“A lot of patients do not know about [palmar and planter hyperhidrosis]. They do not know that they have something that is wrong that can be improved so they live in silence with it,” said Dr. Solish.
“Now with the Internet it helps because . . . they can search [about the problem] and they can see that there are options out there. I think if people have excessive sweating they should just know that it is not normal, but it is not uncommon, and there are options available to improve it.”
Dr. Solish added that palmar and plantar hyperhidrosis patients that he treats with botulinum neurotoxin are his most satisfied patients.
“They are so happy because you have taken something that haunts them everyday. They worry about it, they are self conscious about it, they are not dating, they are afraid to lift their hand in school, or they are afraid to shake someone’s hand . . . and then [after botulinum toxin injections] they just forget about it.”
Originally published in the Sept. 2015 issue of The Chronicle of Skin & Allergy