Applying ice in a very controlled, specific manner minimizes discomfort of botulinum toxin injections for palmar and plantar hyperhidrosis, an expert says.
Niagara Falls, Ontario - Applying ice using a very specific technique can eliminate the need for nerve blocks when performing Botox (botulinum toxin A, Allergan) injections to treat palmar and plantar hyperhidrosis, a researcher says.
"Once one took a patient's hand out of a bucket of ice," explains Dr. Smith, "the whole hand would start warming up," returning to its original temperature within about 30 seconds.
Conversely, he says, "By applying an ice cube directly to the area one plans on injecting, waiting for 15 to 20 seconds and then starting to move the ice cube down along the finger - holding it exactly at the edge of where one is going to inject - we've been able to create a simple, reproducible method" that's effective, sanitary and well-tolerated (Smith KC, Comite SL, Storwick GS. Dermatol Surg. 2007;33:S91-S94).
The technique involves having a patient sit back comfortably on an exam table with knees up, resting the hand to be treated, palm up, on one knee and the anterior thigh. Before injecting, the physician (wearing simple 2x magnifying loupes) or an assistant applies ice directly for 10 to 30 seconds - depending on the sensitivity of the area being treated - to the intended injection point and a 1 cm margin around it, Dr. Smith says.
Next, he advises repositioning the ice so that its edge is within 0.5 cm of the intended injection point. To increase efficiency, one often can reposition the ice adjacent to the injection point in a way that will cool the next injection point, Dr. Smith tells Dermatology Times.
For each injection, he uses a 31-gauge needle inserted almost perpendicular to the skin, to minimize discomfort, to a depth of 1 ml to 2 ml. Regarding injection volume, Dr. Smith says he uses two to five units of Botox reconstituted at 100 units per milliliter in normal saline with benzyl alcohol preservative.
"Because the injection volume is very small," Dr. Smith says, "it hurts less."
If one uses a 2 ml or 3 ml reconstitution instead of 1 ml, one would have to inject a larger amount of fluid to deliver the desired two or three units of botulinum toxin, he explains. "The larger volume creates more pressure in the tissue, and there's a higher chance that the toxin will diffuse."
At a concentration of 100 units per milliliter, a 0.3 ml syringe holds up to 30 units of Botox, or six to 15 0.02 ml to 0.05 ml injections, Dr. Smith says. With use of a BD-II syringe with swaged-on needle (Becton, Dickinson and Co.), patients have reported no increase in bleeding or discomfort from initial injection to final injection with an individual syringe, he says.
"This suggests that dulling of the needle is not a problem," Dr. Smith says. To further reduce discomfort, he says one can apply ice to each injection point for one or two seconds immediately after withdrawing the needle.
Benefits and feedback
Based on patient feedback, Dr. Smith says, "I've been somewhat surprised how well-tolerated the treatment is. One would think that giving 30 or 40 injections into the palm would be pretty painful." However, he says that when he asks patients to rate discomfort on a scale of zero to 10, the typical response is between three and five with the use of ice.
However, he says, "It's very important for anyone reading our paper to pay very strict attention to every little detail" of the technique described.