Patient: A 21-year-old male presented with focal palmar hyperhidrosis, which had been present since age 11. Family history is notable only for the presence of maternal axillary hyperhidrosis. Multiple treatment attempts with anti-perspirants and topical aluminum chloride preparations have not provided him adequate symptom relief, and he complains of significant irritation and stinging with the application of these solutions. Socially, he is graduating college and starting the job interview process and concerned about shaking hands in interview and social settings.
Treatment Issue: Effectively treating focal idiopathic palmar hyperhidrosis.
He was treated with 75 units of botulinum toxin type A (Botox) injected intradermally into each palm. Botulinum toxin for the treatment of focal hyperhidrosis works through chemodenervation of the cholinergic nerve fibers that supply the focally overactive eccrine glands. The duration of efficacy with this method for palmar hyperhidrosis frequently lasts an average of 5 to 6 months.
First, a starch iodine test was performed in order to delineate the most affected areas (see Figure 1).
As for botulinum toxin therapy, our experience has been with a reconstitution of 4 ml of preserved saline for 100 Botox units. Two 1-cc Luer lock syringes with a 30-g needle may be used for each palm, depending on the total dose required. Alternatively, B&D Ultrafine II 50-unit insulin syringes that each hold 0.5 ml are employed. If using the B&D syringes, the needles are already attached, so the Botox vial itself should be opened with a bottle opener in order to remove the rubber stopper prior to filling the syringes. This avoids dulling each B&D needle tip when passing it through the rubber stopper.
The total dose and number of injections should depend on the actual surface area of involvement in the affected palm. Approximately, 20 to 30 intradermal injections (depending on palm size) of 0.07 cc to 0.1 cc aliquots, totaling 50 to 100 Botox units, are used for each palm.
Injections are spaced 1 cm to 1.5 cm apart within the hyperhidrotic regions.
For the thick-skinned palms, needles tend to dull more quickly and therefore when using a 1-cc Luer lock syringe, the 30-g needle on each syringe should be replaced at least once during the procedure. When using a B&D insulin needle, consider using the 0.3-cc syringe size for thicker-skinned patients (instead of the 0.5-cc syringe) so that fewer injections are done with each needle.
Remember when injecting the palms, the thick skin usually prevents easy injection into the dermis. The typical wheal used to identify proper depth placement, which we are accustomed to seeing when treating patients with axillary hyperhidrosis, is often absent; however, a zone of visible blanching is indicative of proper depth.
Slowly insert the needle without placing pressure on the plunger until you are at the appropriate depth. One trick that can be employed for new injectors to help ensure proper superficial placement of the product into the dermis is to use an ADG needle (which comes with CosmoDerm packages) for the Luer lock syringes, or cut off the top 3 mm of the orange B&D cap so that the needle tip is slightly sticking out. Also, keep in mind that upon removing the needle from the skin, sometimes there is a tendency for a few drops of the Botox solution to continue to leak out of the needle tip. To reduce this problem, ensure there are no air bubbles in the syringe and remove your thumb from the plunger as you start removing the needle tip from the skin after each precise injection.
Pain is the most common complaint by patients undergoing palmar Botox treatments. It is quite rare for patients not to require any anesthesia at all. In many patients, icing the palm and frequent breaks can be sufficient to tolerate the injections. This can be helped with talkaesthesia as well as having an assistant hold ice to the next region to be injected. Sometimes holding a vibratory massage device to the wrist can be a helpful adjunct to ice as well (Gates principle). In our experience, topical anesthetics even under occlusion have minimal efficacy. For patients who complain of significant pain or have difficulty keeping their hand still, never blocks (median and ulnar +/- radial) allow for a much-increased tolerability of the procedure. With future treatment, many of these nerve block patients can be converted over to ice and talkaesthesia over time.
Transient weakness is a potential complication of palmar botulinum toxin therapy. This reduction in either grip strength (removing lids from jars) or fine motor finger skills (using nail clippers) can be attributed to injections placed too deeply and/or Botox diffusion to underlying muscles. Although this weakness is relatively infrequent (happening in our experience in less than 15% of patients treated), these symptoms are temporary and patients have reported resolution within days to weeks.
1. When injecting, try to stay superficial and intradermal by looking for either a raised bleb or an area of blanched skin.
2. Provide some degree of pain relief either through ice, vibratory devices (Gates principle) or wrist blocks, as appropriate.
POINTS TO REMEMBER
Reconstitution volumes and dosages for Botox differ among studies for palmar hyperhidrosis. In our experience, it appears more efficacious to treat palm size (and adjust the dose and number of injection points based on surface area of involvement) rather than have a standard number of units to treat each palm. Dosages per palm can often range between 50 units for patients with smaller hands (often smaller women and adolescents) to 100 units for those with larger hands.
Palmar injections below the dermis have an increased risk of hand weakness and should be avoided. Furthermore, consider using a lower dose in the hands if grip strength or fine motor skill is critical to the individual’s work or lifestyle (e.g., draftsmen, musicians, professional athletes, surgeons).
In cases of concern regarding hand weakness, treatments are initiated at a low dose or started with the non-dominant hand.