A 40-year-old Caucasian woman presented to the clinic for persistent sweating of the bilateral hands, including the volar surface of the hand extending to the respective surfaces of the digits beginning approximately 20 years ago. Unsuccessful prior therapies include antiperspirants, the use of an iontophoresis device, and glycopyrrolate. Her past medical history and past surgical history were insignificant in relation to the chief complaint.
On physical examination, she presented with impressive damp palms and digits, bilaterally. A diagnosis of localized chronic palmar hyperhidrosis was made.
The treatment plan consisted of 200 units of Jeuveau (prabotulinumtoxinA-xvfs) to each volar surface of the hand in a grid-like pattern for a total of 400 units. The patient was instructed that the treatment would take full effect in two weeks, hopefully bringing relief from her symptoms for approximately three months. During the time between treatments, she was instructed to reinitiate iontophoresis and topical antiperspirants to potentiate the effects of the toxin for a longer period of time before repeated treatment. She returned to the clinic in two weeks with great improvement in symptoms and quality of life. She denied any muscular weakness or other side effects from the treatment.
Discussion
We present this practical use of botulinum toxin as 3% to 4.8% of the population has palmar hyperhidrosis, defined by excessive sweating at the volar surfaces of the hands and digits due to an inappropriate stimulation of the sympathetic branch of the autonomic nervous system. Palmar hyperhidrosis is further aggravated by stressful situations, without regard to seasons or the biological need to carry out heat loss, ultimately negatively impacting their quality of life.1,2 Only 51% of known patients with palmar hyperhidrosis will present with this chief complaint, highlighting a potential underestimated degree of prevalence within the population.2
Hyperhidrosis is characterized as primary with an idiopathic onset being earlier in life or secondary which is due to underlying pathology with recent onset. The condition is then further divided by being generalized, affecting the entire body or focal, affecting portions of the body.2 Typically hyperhidrosis will correlate with areas of the body that are high in eccrine gland density, such as the palms as in our patient’s case. It is important to note that the number of eccrine glands is not thought to contribute to the development of the condition, but rather overactivity of the postganglionic sympathetic cholinergic fibers supplying the glands. Studies looking at the gland ultrastructure of a patient with hyperhidrosis was found to support normal structure.3,4 Iatrogenic and genetic causes have been found to result in hyperhidrosis.2
Topical treatments include a range of over-the-counter to prescription aluminum-based antiperspirants which block eccrine glands, resulting in eventual degeneration of the duct epithelium and secretory cells of the glands. These products must be reapplied and can be irritating to the skin.5 Other topical agents are being developed using oxybutynin and glycopyrrolate/glycopyrronium. At this time, evidence is insufficient for palmar hyperhidrosis as palmar volar skin thickness must be taken into account.5
Iontophoresis treatment is thought to use electrical current of 15 to 20 milliamperes on the skin while in tap water for 15 to 40 minutes three to four times weekly to encourage eccrine gland blockades, disruption of sympathetic conduction, pH reduction, and disruption of electrochemical gradients needed to secrete sweat depending on patient locations. At times, tap water can have insufficient mineral load so the current is not effective.5 Our patient reported past use of iontophoresis to be uncomfortable. We asked her to trial again with a new device. We reviewed the literature and found that this method can cause tingling, burning transient lesions that can be symptomatically treated with moisturization, topical steroids, and changes in prescribed use of the machine.5 Some patients could potentially be noncompliant given the number of sessions needed and space constraints.
Surgical intervention can be employed to destroy the sweat glands,5 but the main concern with this method is the risk of scarring and keloid formation, as well as other side effects. Further, if treating focal hyperhidrosis, this can further cause a detriment in quality of life functionally and socially.
Purified botulinum toxin Type A complex can be a valuable, noninvasive, longer-lasting alternative for focal hyperhidrosis, although it cannot be used in pregnancy or during breastfeeding, or in patients with myasthenia gravis.5 This treatment method removes time constraints, skin thickness limitations, is completed as an outpatient procedure, and removes other dependent variables.5 In those who are treated for palmar hyperhidrosis, the toxin should be administered in a grid-like fashion on all volar surfaces.5 Literature suggests 0.1 to 0.2 milliliters per centimeter squared at 1 to 2.5 U per 0.1 milliliters is optimal while accounting for diffusion of 1 to 2 centimeters.5 These specifications suggest 100 to 150 units per hand.5 After discussion with the patient, we opted to inject 200 units of Jeuveau at each complete volar surface, totaling 400 units of Jeuveau. Drawbacks include repeat injections every three months, potential muscle weakness,6 and pain at the injection site. We elected to use cryoanesthesia (via ice packs) for approximately 10 minutes before the procedure and advised our patient to try to potentiate the effects of the toxin by also using an iontophoresis device. The literature shows an 80% to 90% anhidrotic effect beginning three days post-treatment.5 The skin on the palms is thick, so it is important to ensure appropriate administration and to change needles as needed for the comfort of the patient.7
Other treatment methods are being developed, such as systemic anticholinergic medications,5 although we will not discuss those here as we were concerned with our patient’s chief complaint of focal palmar hyperhidrosis.
In conclusion, we present this case as palmar hyperhidrosis is common and almost half of those patients do not seek help, suggesting that the prevalence is underestimated. Dermatologists and other providers should be aware of this condition and associated treatment options as treatment leads to an improved quality of life both functionally and socially. We should strive to advocate for the diagnosis and adequate treatment of palmar hyperhidrosis.