COEUR D’ALENE, IDAHO – By the time patients seek a physician’s help for palmar/plantar focal hyperhidrosis, they may be well beyond the point at which even potent topical antiperspirants will help.
"Most people think there is nothing that can be done at all [for these patients]. But there are effective options. Even if you’re not going to offer them, get your patients to someone who will. We can make a profound difference for children and adolescents," Dr. Jane S. Bellet said at the annual meeting of the Society for Pediatric Dermatology.
Dr. Jane S. Bellet
In fact, more potent therapies are available, ranging from iontophoresis to oral medications, botulinum toxin A injections, and surgical thoracic sympathetectomy.
Oral medications: "I’ve really changed my practice in the last 5 years. I didn’t use systemic medications very much. I use them much more frequently now. I think you can get a very nice response," said Dr. Bellet, a pediatric dermatologist at Duke University in Durham, N.C.
She typically turns to the anticholinergic agents glycopyrrolate and oxybutynin. Glycopyrrolate, marketed as Cuvposa in a cherry-flavored solution at 1 mg/5 mL, does not have an indication from the Food and Drug Administration for treatment of pediatric hyperhidrosis, she noted. However, it is FDA-approved in 3- to 16-year-olds for severe chronic drooling caused by neurologic disorders.
"Although we don’t have an indication for hyperhidrosis, we do have a pediatric indication, and I think many times that puts our parents at ease," she observed.
Glycopyrrolate is cost effective and painless, although approximately 30% of children treated for hyperhidrosis will develop dry mouth and/or dry eyes.
"I would definitely add glycopyrrolate to your armamentarium. I think the biggest concern most of us have is the side effects. Speak about them with the family ahead of time, guide them as to what to expect, and stop if it becomes intolerable," Dr. Bellet said.
A recent randomized, prospective, controlled clinical trial in 45 children aged 7-14 years with palmar hyperhidrosis showed excellent outcomes with oxybutynin (Ditropan), with more than 85% experiencing at least moderate improvement in sweating and 80% gaining improved quality of life (Pediatr. Dermatol. 2014;31:48-53).
Iontophoresis: "This is a wonderful treatment for palms and soles," said Dr. Bellet.
The treatment entails placing the hands or feet in a water bath tray filled with tap water through which direct electric current is running. The proposed mechanism of benefit is that hydrolysis of the bath water results in accumulation of hydrogen ions, which then induce sweat gland destruction.
The chief disadvantage of iontophoresis is that it is labor intensive. Unless the family rents or buys a home unit, the patient typically must visit the physician’s office on a daily basis initially, placing the hands or feet in the bath for 10 minutes, followed by a second 10-minute round after the polarity is switched. Eventually, many patients can step down to two or three 20- to 30-minute sessions per week, then perhaps once-weekly maintenance therapy, she said.
Adding glycopyrrolate to the water bath has been shown to result in longer improvement in a study in both children and adults (Australas. J. Dermatol. 2004;45:208-12); however, this poses a greater risk of systemic absorption in children.
"Interestingly enough, some insurance companies will cover iontophoresis if you add glycopyrrolate to the water, but they won’t cover regular iontophoresis," Dr. Bellet said.
In response to audience inquiries, she indicated she uses the Fischer MD-1a galvanic unit. It’s simple to operate, costs about $700 including accessories, and can be rented with the payments applied to a later purchase.
Botulinum toxin A: First using this product for hyperhidrosis is off-label therapy, Dr. Bellet emphasized. Second, the doses required to treat palmar/plantar hyperhidrosis – 75-100 units per palm or sole – are much higher than in treating the axillae. Also, injecting botulinum toxin A into the palms and soles is extraordinarily painful. Children typically require general anesthesia, because the alternative methods employed with mixed results in adults, including EMLA cream, ice packs, and ethyl chloride spray, don’t cut it in younger patients, Dr. Bellet noted.
That being said, botulinum toxin A therapy works quite well in children and adolescents. However, it’s important to explain to patients and parents up front that the injections can cause transient weakness of the hand muscles because of the diffusion of the toxin from dermis to muscles; for a budding pianist or baseball pitcher, that can be a deal-breaker, she said. Also, Dr. Bellet added, repeated injections can result in atrophy of the thenar and hypothenar eminences, with resultant irreversible weakness.