NAPLES, FLA. Botulinum toxin may be a good treatment for primary focal hyperhidrosis, but for patients with hand or foot hyperhidrosis you should try iontophoresis first, Lewis P. Stolman, M.D., said at the annual meeting of the Florida Society of Dermatology and Dermatologic Surgery.
What you do not want to do for hyperhidrosis is refer patients for sympathectomy, he added, except as a very last resort.
The majority of patients who undergo sympathectomy for focal hyperhidrosis develop compensatory, and often severe, hyperhidrosis that can be more dispiriting and debilitating than their original condition, said Dr. Stolman of New Jersey Medical School, Newark.
"I don't think we as dermatologists should be referring patients for sympathectomy quite as quickly as we do," Dr. Stolman said.
Compensatory hyperhidrosis is an acknowledged consequence of sympathectomy, and in reported case series the incidence has ranged as high as 67%. In a recent review of reports, the incidence of compensatory hyperhidrosis in 22,000 patients was 52%.
For some patients, the compensatory hyperhidrosis is minor and localized to a limited area, and can be managed with botulinum toxin treatment. But it can also be much more severe, Dr. Stolman said.
Iontophoresis has a number of advantages over botulinum toxin, and may be equally effective, Dr. Stolman said. He was one of the early researchers in the use of iontophoresis for this condition but receives no money or grants from any manufacturer of iontophoresis equipment.
Botulinum toxin treatment has been reported to have an efficacy rate of 75%95% for axillary hyperhidrosis. In his experience, 85%90% of patients treated with iontophoresis for palmar or plantar hyperhidrosis have satisfactory improvement, and another 5% are improved when Robinul (glycopyrrolate) is added to the trays of water used for the technique, Dr. Stolman said.
Iontophoresis is probably less expensive than botulinum toxin. A 50-U botulinum toxin treatment costs at least $250, and about half of patients will require two treatments to achieve good control. Medicare reimburses an iontophoresis treatment at $24.69, and most patients need four to six treatments to achieve good control. Patients can also purchase their own equipment.
Two devices exist on the market. One costs $150, the battery-operated Drionic device, and the other costs $650, the Fischer MD-1a galvanic unit, which transforms alternating current to direct current. Though the devices are simple equipment, Dr. Stolman said he much prefers the more expensive device.
"The Drionic device in my opinion has given iontophoresis a bad rap because it is rarely effective," he said. "It is not the equal of the Fischer galvanic device in its efficacy, even though the literature may indicate that it is."
Moreover, unlike botulinum toxin, there is no chance of loss of any fine motor control with iontophoresis, Dr. Stolman added.
Most patients can treat themselves at home. The patient attaches the device's cathode to one tray of water and the anode to another tray, submerges their entire palms, one hand in each tray, and turns up the current to 1518 mA for 10 minutes. Once patients have achieved control of their hyperhidrosis with four to six treatments, they repeat it whenever necessary, Dr. Stolman said. For some individuals that is every few weeks, and for others it is every week.
The sole drawback to iontophoresis is that it does not work well for axillary hyperhidrosis because it is difficult to attach the electrodes to the axillas, and many patients develop irritation.
The mechanism of action of iontophoresis is unclear, Dr. Stolman said. It may cause occlusion of the distal end of the sweat ducts by thickening the stratum corneum. It has been shown that when the stratum corneum in treated areas is stripped off with adhesive tape, the effect is reversed. Biopsy has shown no change in sweat gland structure.
An exciting recent development in the use of iontophoresis, Dr. Stolman said, is that it has now been shown that botulinum toxin can be added to the water trays, and is delivered effectively by the technique.
"Maybe we will find a way to get prolonged suppression of palmar hyperhidrosis for many months, as we do for the axillas, without painful injection," Dr. Stolman said.