Palmar and plantar hyperhidrosis is relatively common and can have severe psychological and medical consequences for those afflicted. A multitude of treatments exist but are often inadequate especially for those with significant disease. In these cases botulinum neurotoxin provides a reliable method for reducing the symptoms and improving quality of life. Although actual administration is relatively straightforward, pain management is a crucial component that requires a mastery of several techniques. Patients have a high degree of satisfaction with botulinum neurotoxin treatment and are motivated to come back for repeat treatments, usually every 6 months.
Key points
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Palmar and plantar hyperhidrosis is relatively common and can have severe psychological and medical consequences for those afflicted.
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A multitude of treatments exist but are often inadequate especially for those with significant disease; in these cases BoNT, in its various formulations, provides a reliable method for reducing the symptoms and improving QOL.
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Although the actual administration is relatively straightforward pain management is a crucial component that requires a mastery of several techniques.
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Patients have a high degree of satisfaction with BoNT treatment and are motivated to come back for repeat treatments, usually every 6 months.
Introduction and overview
Hyperhidrosis (HH) is an excessive sweating disorder that affects approximately 2.8% of the population in the United States, likely with similar incidences in other countries. It is commonly defined as sweating beyond what is expected for environmental conditions and thermoregulation with duration of more than 6 months. Some have added specific diagnostic criteria, which are discussed later and do apply to the palms and soles. A quantitative definition of HH as the production of more than 50 mg of sweat in one palm per minute has also been suggested for use in studies and when examining therapeutic intervention ; however, this fails to account for surface area. Clinically, sweating is considered excessive if it significantly interferes with daily life.
HH can be classified as primary or secondary and further as general or focal. Focal is further subclassified by anatomic area. Eccrine glands cover most of the body and have a density of approximately 60/cm 2 , except on the palms and soles where their density is at approximately 600/cm 2 . It is thus not surprising that patients experience HH in areas of high eccrine density, such as the soles (30%) and palms (24%). It should be noted that in primary focal HH, neither the number, density, nor size of eccrine glands are abnormal; rather, there is overactivity of the postganglionic sympathetic cholinergic fibers (sudomotor) innervating them. This explains the effectiveness of botulinum neurotoxin (BoNT).
In clinical practice significantly more patients present with axillary than palmar HH and more with palmar than plantar HH. In many cases individuals suffer with more than one site involved. Most patients who present with palmar HH have had the condition since childhood or early adolescence with no known cause and report “sweaty palms” that cause them social embarrassment. The effects later in life are physical and emotional. Physically, the wetness may be bothersome enough that patients go to great lengths to avoid shaking peoples hands and frequently hide their hands in their pockets. Plantar HH may cause patients to frequently change their socks and slip in their shoes. HH is a well-established risk factor for cutaneous infection and eczematous dermatitis. Psychologically HH causes anxiety, emotional distress, embarrassment, and a markedly diminished quality of life (QOL). Interestingly, a study by Lear and colleagues suggested that spontaneous regression might occur over time because there is a low prevalence of the disorder in the elderly population.
Multiple modalities are available for treatment of primary focal HH, including topical medications, such as aluminum chloride ; oral medications, such as clonidine ; physical treatments, such iontophoresis ; injectable treatments, such as BoNT; and even surgical sympathectomy.
In this article, the role of BoNT in the treatment of primary focal HH of the palms and soles is discussed.
Introduction and overview
Hyperhidrosis (HH) is an excessive sweating disorder that affects approximately 2.8% of the population in the United States, likely with similar incidences in other countries. It is commonly defined as sweating beyond what is expected for environmental conditions and thermoregulation with duration of more than 6 months. Some have added specific diagnostic criteria, which are discussed later and do apply to the palms and soles. A quantitative definition of HH as the production of more than 50 mg of sweat in one palm per minute has also been suggested for use in studies and when examining therapeutic intervention ; however, this fails to account for surface area. Clinically, sweating is considered excessive if it significantly interferes with daily life.
HH can be classified as primary or secondary and further as general or focal. Focal is further subclassified by anatomic area. Eccrine glands cover most of the body and have a density of approximately 60/cm 2 , except on the palms and soles where their density is at approximately 600/cm 2 . It is thus not surprising that patients experience HH in areas of high eccrine density, such as the soles (30%) and palms (24%). It should be noted that in primary focal HH, neither the number, density, nor size of eccrine glands are abnormal; rather, there is overactivity of the postganglionic sympathetic cholinergic fibers (sudomotor) innervating them. This explains the effectiveness of botulinum neurotoxin (BoNT).
In clinical practice significantly more patients present with axillary than palmar HH and more with palmar than plantar HH. In many cases individuals suffer with more than one site involved. Most patients who present with palmar HH have had the condition since childhood or early adolescence with no known cause and report “sweaty palms” that cause them social embarrassment. The effects later in life are physical and emotional. Physically, the wetness may be bothersome enough that patients go to great lengths to avoid shaking peoples hands and frequently hide their hands in their pockets. Plantar HH may cause patients to frequently change their socks and slip in their shoes. HH is a well-established risk factor for cutaneous infection and eczematous dermatitis. Psychologically HH causes anxiety, emotional distress, embarrassment, and a markedly diminished quality of life (QOL). Interestingly, a study by Lear and colleagues suggested that spontaneous regression might occur over time because there is a low prevalence of the disorder in the elderly population.
Multiple modalities are available for treatment of primary focal HH, including topical medications, such as aluminum chloride ; oral medications, such as clonidine ; physical treatments, such iontophoresis ; injectable treatments, such as BoNT; and even surgical sympathectomy.
In this article, the role of BoNT in the treatment of primary focal HH of the palms and soles is discussed.
Patient evaluation
A careful clinical history and focused physical are imperative. The first fact to establish is whether the patient has primary or secondary HH. There are many causes of secondary HH that have been well documented previously and include febrile illness (ie, chronic infections), endocrine disorders (thyroid dysfunction), medication use (ie, antidepressants), and cancer (ie, pheochromcytoma). Secondary is more likely if the sweating is associated with other constitutional symptoms and is generalized in nature. If secondary HH is suspected the work-up should at minimum include a complete blood count, fasting glucose level, and thyroid function tests. Any suspected offending medications should be discontinued and if necessary appropriately substituted. Further investigations should be guided by elements of the history and the examination.
The generally accepted diagnostic criteria for HH in general and palmar-plantar specifically is excessive sweating that lasts at least 6 months without any obvious cause and has at least two of the following features: impairs daily activities, a bilateral and relatively symmetric pattern of sweating occurring at least once per week, an age of onset younger than 25 years, cessation of focal sweating during sleep, or positive family history. Bilaterality is not a diagnostic criteria and it should be noted that palmar HH can present unilaterally in 6% of cases.
It is important to quantify the impact of HH on the patient’s QOL. This not only helps to decide on the need for and success of treatment but may also aide in obtaining insurance approval for treatment. The HH Disease Severity Scale (HDSS) is an easy tool for this ( Table 1 ).
| “How Would You Rate the Severity of Your Hyperhidrosis?” | Score | Clinical Interpretation | |
|---|---|---|---|
| Patient Response | |||
| 1 | My sweating is never noticeable and never interferes with my daily activities | 1 | Mild |
| 2 | My sweating is tolerable but sometimes interferes with my daily activities | 2 | Moderate |
| 3 | My sweating is barely tolerable and frequently interferes with my daily activities | 3 | Severe |
| 4 | My sweating is intolerable and always interferes with my daily activities | 4 | Very severe |
It is important to take a family history because there is evidence that primary HH is an autosomal-dominant trait with variable penetrance.
Management goals and strategy
The goal of management is to improve the quality of the patient’s life with acceptable risks. QOL studies have in general shown a significant improvement in the QOL after treatment of axillary, for palmar and planter HH.
Several methods have been used to measure the amount of palmar and plantar sweating before and after treatment. These include the evaporimeter, persprint paper, patient reports of the number of days of dryness, digitized ninhydrine test, gravimetry sweat production test, the Minor iodine starch test, and the HDSS. We clinically prefer the HDSS because it is easy and quick to administer and has been found to be a reliable diagnostic tool. It can also be used to monitor the effectiveness of treatment. Success may be considered a reduction in HDSS of 1 or more. Although a subjective test, it accurately reflects patient QOL, which is most relevant to patients.
The Canadian Hyperhidrosis Advisory Committee has made several treatment recommendations. In review, the committee recommends topical aluminum chloride as a first-line option, in a concentration of 20% to 50% for treating mild focal or multifocal HH. For patients with moderate to severe HH, the committee recommends starting treatment with topical aluminum chloride and, if ineffective, trying iontophoresis or onabotulinumtoxinA (A/Ona) injections. Surgery should be reserved for patients who do not respond to less invasive interventions. Of note, endoscopic thoracic sympathectomy although established may have significant complications and deleterious side effects including compensatory HH. Surgery should be reserved for patients in whom less invasive treatments have proved ineffective and who understand the risks and benefits of the surgery.
BoNT
There are four types of BoNTs approved by the Food and Drug Administration for clinical use in the United States: A/Ona (Botox; Allergan, Irvine, CA), A/Inco (Xeomin; Merz Pharmaceuticals, Greenboro, NC), abobotulinumtoxinA (A/Abo; Dysport; Medicis, Scottsdale, AZ), and rimabotulinumtoxinB (B/Rima, Myobloc; Solstice Neurosciences, Louisville, KY).
BoNTs block the release of acetylcholine and several other neurotransmitters from presynaptic vesicles by deactivating SNARE proteins. These toxins use different presynaptic proteins for their site of action. For instance, for A/Ona the protein is synaptin 25.
There are several important facts that must be considered before instituting therapy with BoNT. First, all four types of commercially available BoNT are considered pregnancy category C drugs and one should avoid injection in actively nursing women. Second, treatment of the palms and soles for primary focal HH is considered an off-label use of BoNT. Third, one must always screen for previous allergic reaction to BoNT. Fourth, one must be aware of the patient’s current medication list because certain medications can theoretically alter the metabolism of neurotoxin, such as aminoglycoside antibacterials, cholinesterase inhibitors, and calcium channel antagonists. Finally, the use of BoNT can exacerbate some neuromuscular disorders, such as myasthenia gravis.
Evaluation of treatment and recommendations
There are many different types of studies for BoNT treatment of palmar and plantar HH. The placebo-controlled evidence for palmar HH is reviewed in Table 2 . There is one single-agent study each for A/Abo, A/Ona, and B/Rima. These studies are small and of short duration; however, they do confirm the effectiveness of these products. This allows the conclusion that the evidence supports a Level B recommendation for BoNT-A and a Level C recommendation for BoNT-B for the treatment of palmar HH. On further examination of the evidence one can conclude that there are insufficient data for the individual formulations, so each receives a Level U recommendation. The side effects were in the order of what is expected and are covered in more detail in the complications section.
| Reference | AAN Class | Design | N | Follow-Up | Agent | Dose | Results | Adverse Events |
|---|---|---|---|---|---|---|---|---|
| Placebo-Controled Studies | ||||||||
| Schnider et al, 1997 | II | R, DB, PC Within-group comparison | 11 | 13 wk | A/Abo | 120 MU/palm PCO contralateral palm | Sweat production dropped: 26%, 26%, and 31% at wk 3, 8, 13 ( P <.001) and improvement in VAS 38%, 40% and 35% at wk 3, 8, 13, respectively ( P = .002) | Minor, reversible weakness of handgrip lasting 2 and 5 wk In three patients. |
| Lowe et al, 2002 | II | R, DB, PC | 19 | 28 d | A/Ona | 100 U/palm, PCO in contralateral palm | Percentage change from baseline was greater A/On-treated palms at day 28 ( P = .0037). Minor test confirmed results. | Finger tingling and numbness in one A/Ona patient. One patient bilateral hand pain. |
| Baumann et al, 2005 | II | R, DB, PC | 20 | 120 d or event-driven until return of sweating | B/Rima | 5000 U/palm or PCO | Patient assessed efficacy significant difference B/Rima through day 120. Physician assessment no difference at day 30. Mean duration of effect; 3.8 mo. | Transient dry mouth in 18. Transient muscle weakness in 12. |
| Comparative Studies | ||||||||
| Simonetta Moreau et al, 2003 | II | R, DB, active | 8 | 6 mo | A/Ona or A/Abo | A/Ona, 69 U/palm, or A/Abo, 284 U | Decrease in mean PSA; 76.8% A/Abo ( P = .002) vs 56.6% A/Ona ( P = .003) at 1 mo. At 3 mo decrease in PSA was 69.4%, A/Abo ( P = .008) and 48.8%. A/Ona (NS). Mean duration of benefit 17 wk A/Abo; 18 wk A/Ona. | Pinch weakness, two times more frequent in A/Abo than A/Inco. |
| Saadia et al, 2001 | II | R, SB, comparison of two doses, intraindividual comparison | 24 | 6 mo | A/Ona | 50 U or 100 U/palm | Significant decrease in sweating within 1 mo. At 6 mo anhidrotic effect evident in both dose groups. Both doses effective at 1 mo and lasted 6 mo in low-dose, 5 mo in high-dose groups. | No difference in hand grip strength. Finger pinch strength decreased. |
| Campanati et al, 2014 | II | R, DB | 25 | 6 mo | A/Ona and A/Inco | A/Ona, 100–150 U/palm, and A/Inco, 100–150 U in other palm | A/Ona and A/Inco equivalent short- and long-term effects. | No difference in muscle strength between A/Ona and A/Inco. |
| Rystedt et al, 2013 | II | R, DB | 20 | 3 mo | A/Ona, A/Inco B/Rima, A/Abo | Varying doses | Optimal doses of A/Ona, A/Abdo, A/Inco, and B/Rima: 25 U/mL, 40 U/mL, 25 U/mL. | N/A |
Related posts:
Incidence and Prevalence of Hyperhidrosis
Impact of Hyperhidrosis on Quality of Life and its Assessment
Special Considerations for Children with Hyperhidrosis
Botulinum Toxin for Hyperhidrosis of Areas Other than the Axillae and Palms/Soles
Oral Medications
Local Procedural Approaches for Axillary Hyperhidrosis
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