Side-effects of intradermal injections of botulinum A toxin in the treatment of palmar hyperhidrosis: a neurophysiological study

Therapeutic Effectiveness of Needle Injection Versus Needle-Free Jet Injector System for Botulinum Toxin Type A in Palmar Hyperhidrosis

BACKGROUND

The most important problem with local injections of botulinum toxin type A (BTX-A) in palmar hyperhidrosis is pain during the injections.

OBJECTIVES

We evaluated therapeutic effectiveness and pain of local injections of BTX-A using needle-free direct administration system.

METHODS

We performed BTX-A local injection therapy using a conventional injection needle in the left hand and a needle-free direct administration system in the right hand.

RESULTS

A reduction in the quantity of perspiration was observed 4 weeks after administration of both Needle and Needle-free BTX-A, and reduction was maintained throughout 28 weeks observation period. Both hyperhidrosis Disease Severity Scale scores and Dermatology Life Quality Index for hands treated with Needle BTX-A and hands treated with Needle-free BTX-A had decreased significantly by 4 weeks after treatment. Pain visual analog scale scores and the degree of pain were significantly lower in hands treated with Needle-free BTX-A than in hands treated with Needle BTX-A.

CONCLUSIONS

When the trigger of the pressurized needle-free injector device is activated, the gas powered driving pressure propels BTX-A through an orifice (0.13 mm) about four times narrower than a 30 G needle at very high speed. As most pain occurs during the needle prick itself, the advantage of a small orifice coupled with high-speed penetration of BTX-A through the pressurized device results in reduced pain during administration. The needle-free direct administration system administers the injectate under the skin without a visible needle.

Motor Unit Number Estimation in Spastic Biceps Brachii Muscles of Chronic Stroke Survivors Before and After BoNT Injection

OBJECTIVE

The study aims to characterize the motor unit (MU) loss in spastic biceps brachii muscle (BBM) of chronic stroke survivors before and after botulinum neurotoxin (BoNT) injection.

METHODS

High-density weighted average (HDWA) motor unit number estimation (MUNE) was employed to estimate the number of functioning motor units of BBMs of eight chronic stroke survivors 1-week before (1st visit) and 3-week after (2nd visit) BoNT injection based on the surface electromyography (sEMG) signals recorded during voluntary contraction and supramaximal electrical stimulation.

RESULT

Significant lower MUNE was estimated from the spastic BBMs compared to the non-spastic MUNEs during two visits. A surprisingly higher MUNE was obtained from the spastic side during the 2nd visit after BoNT injection.

CONCLUSIONS

The HDWA MUNE technique can be employed to characterize the motor unit loss in spastic muscle caused by upper motor neuro lesions at contraction level up to 30% MVC, but may fail to detect the MU loss caused by the chemodenervation effect of BoNT due to the non-uniform denervation of small and large size MUs.

SIGNIFICANCE

This study presents the first effort to evaluate the applicability of HDWA MUNE technique to characterize the MU loss in the spastic muscle following stroke and the subsequent BoNT injection for the treatment of post-stroke spasticity. The finding of this study suggests that HDWA MUNE can be a sensitive approach to detect the MU loss in spastic muscles after stroke, but the large inter-subject MUNE variability after the BoNT injection should be interpreted with caution.

Retrospective analysis of the efficacy and duration of botulinum toxin A injections in 30 patients with palmar hyperhidrosis

Palmar hyperhidrosis is a common disorder characterised by excessive sweating due to hyperfunction of the sweat glands. It can be classified as primary disease, or secondary to other causes. It has a high morbidity, and a range of treatment options. Botulinum toxin injections inhibit the release of acetylcholine from the presynaptic receptors. It is an effective treatment; however, it is infrequently selected as only axillary hyperhidrosis currently attracts a Medicare subsidy. We conducted a retrospective review of 30 patients at a Sydney dermatology clinic who received botulinum toxin injections for palmar hyperhidrosis within the past 5 years. This study has the largest patient cohort with this condition in Australia. There was evidence for a median reduction in the Hyperhidrosis Disease Severity Scale, a qualitative self-reported score, as well as an increasing duration of efficacy with repeated injections. There were minimal side-effects of weakness and numbness. There is also an association between treatment of palmar disease and improvement in plantar disease, which suggests that treatment of palmar hyperhidrosis should be considered earlier and more frequently.

Improving Botulinum Toxin Efficiency in Treating Post-Stroke Spasticity Using 3D Innervation Zone Imaging

Spasticity is a common post-stroke syndrome that imposes significant adverse impacts on patients and caregivers. This study aims to improve the efficiency of botulinum toxin (BoNT) in managing spasticity, by utilizing a three-dimensional innervation zone imaging (3DIZI) technique based on high-density surface electromyography (HD-sEMG) recordings. Stroke subjects were randomly assigned to two groups: the control group ([Formula: see text]) which received standard ultrasound-guided injections, and the experimental group ([Formula: see text]) which received 3DIZI-guided injections. The amount of BoNT given was consistent for all subjects. The Modified Ashworth Scale (MAS), compound muscle action potential (CMAP) and muscle activation volume (MAV) from bilateral biceps brachii muscles were obtained at the baseline, 3 weeks, and 3 months after injection. Intra-group and inter-group comparisons of MAS, CMAP amplitude and MAV were performed. An overall improvement in MAS of spastic elbow flexors was observed during the 3-week visit ([Formula: see text]), yet no statistically significant difference found with intra-group or inter-group analysis. Compared to the baseline, a significant reduction of CMAP amplitude and MAV were observed in the spastic biceps muscles of both groups at 3-week post-injection, and returned to approximate baseline value at 12-week post injection. A significantly higher reduction was found in CMAP amplitude ([Formula: see text]% versus [Formula: see text]%, [Formula: see text]) and MAV ([Formula: see text]% versus [Formula: see text]%, [Formula: see text]) in the experimental group compared to the control group. The study has demonstrated preliminary evidence that precisely directing BoNT to the innervation zones (IZs) localized by 3DIZI leads to a significantly higher treatment efficiency improvement in spasticity management. Results have also shown the feasibility of developing a personalized BoNT injection technique for the optimization of clinical treatment for post-stroke spasticity using proposed 3DIZI technique.

The Use of Ultrasound Guidance for the Treatment of Raynaud Disease of the Hand With Botulinum Toxin

BACKGROUND

This study sought to examine the feasibility and effectiveness of the use of ultrasound (US) as a clinical adjunct in the delivery of botulinum toxin for the treatment of Raynaud disease of the hand.

METHODS

One cadaver hand was injected with a colored simulation material using the current traditional surface anatomy approach, whereas an additional cadaver hand was injected using US guidance. The hands were dissected and areas of distribution of the simulation material were evaluated. Five patients diagnosed with Raynaud disease were treated with botulinum toxin using US guidance and data using the Patient-Reported Outcomes Measurement Information System Upper Extremity were collected.

RESULTS

The cadaver hand injected with a colored simulation material using US guidance demonstrated significantly reduced surface area of muscle infiltrated compared with the cadaver hand injected using the traditional surface anatomy approach (16 cm vs 37 cm, P < 0.001).All 5 patients treated with botulinum toxin using US guidance reported significant improvement in symptoms and function after injection (P < 0.05), where zero patients reported intrinsic hand weakness.

CONCLUSIONS

The use of US significantly improves the accuracy of delivery of a surrogate dye in a cadaver model of Raynaud disease, whereas its use clinically results in at least as effective a treatment as the landmark approach, but with less botulinum toxin required to achieve the clinical effect.

Injectable and topical neurotoxins in dermatology: Indications, adverse events, and controversies

The use of neuromodulators for therapeutic and cosmetic indications has proven to be remarkably safe. While aesthetic and functional adverse events are uncommon, each anatomic region has its own set of risks of which the physician and patient must be aware before treatment. The therapeutic usages of botulinum toxins now include multiple specialties and multiple indications. New aesthetic indications have also developed, and there has been an increased utilization of combination therapies to combat the effects of global aging. In the second article in this continuing medical education series, we review the prevention and treatment of adverse events, therapeutic and novel aesthetic indications, controversies, and a brief overview of combination therapies.

Efficacy of botulinum toxin type B for the treatment of primary palmar hyperhidrosis: a prospective, open, single-blind, multi-centre study

Primary palmar hyperhidrosis is a distressing and disabling condition that can produce social, psychological and occupational problems. Although the use of botulinum toxin type A (BoNT-A) has been reported as an efficacious and safe intervention to improve palmar hyperhidrosis, only one study concerned botulinum toxin type B (BoNT-B) in this disorder. The aim of study was to evaluate the efficacy and safety of BoNT-B in treating primary palmar hyperhidrosis. Participants were injected with 5,000 IU of BoNT-B in each palm. Visual analogue test (VAS) to evaluate the intensity of decrease in sweat production, Minor's iodine starch test and measurement of paper towels' weight were used to ascertain palmar sweating at baseline, 4, 12 and 24 weeks after BoNT-B injections by a blind examiner. Thirty-two subjects (12 males, 20 females, mean age 31 ± 11) were enrolled. Significant reduction of palmar sweating was detected after BoNT-B injection: 2.9 ± 1.4, 0.3 ± 0.4, 0.9 ± 0.8, and 2.1 ± 1.5 g (p < 0.001) of paper towels' weight for the right palm at baseline, 4, 12 and 24 weeks; and 2.8 ± 1.7, 0.5 ± 0.6, 0.8 ± 0.7, and 1.8 ± 1.25 g (p < 0.001) at same time, respectively for the left palm. Significant reduction of mean VAS values were also detected after BoNT-B injections: 8.6 ± 1.1, 0.6 ± 0.8, 3.5 ± 2.5, and 7.1 ± 2.4 (p < 0.0001) at baseline, 4, 12 and 24 weeks, respectively. Mild side effects consisting in local pain and hand weakness were observed in 4 (12.5%) subjects. The findings indicated that the use of 5,000 IU BoNT-B injection in each palm was safe and significantly improved the severity of palmar hyperhidrosis.

Molecular mechanisms of treadmill therapy on neuromuscular atrophy induced via botulinum toxin A

Botulinum toxin A (BoNT-A) is a bacterial zinc-dependent endopeptidase that acts specifically on neuromuscular junctions. BoNT-A blocks the release of acetylcholine, thereby decreasing the ability of a spastic muscle to generate forceful contraction, which results in a temporal local weakness and the atrophy of targeted muscles. BoNT-A-induced temporal muscle weakness has been used to manage skeletal muscle spasticity, such as poststroke spasticity, cerebral palsy, and cervical dystonia. However, the combined effect of treadmill exercise and BoNT-A treatment is not well understood. We previously demonstrated that for rats, following BoNT-A injection in the gastrocnemius muscle, treadmill running improved the recovery of the sciatic functional index (SFI), muscle contraction strength, and compound muscle action potential (CMAP) amplitude and area. Treadmill training had no influence on gastrocnemius mass that received BoNT-A injection, but it improved the maximal contraction force of the gastrocnemius, and upregulation of GAP-43, IGF-1, Myo-D, Myf-5, myogenin, and acetylcholine receptor (AChR) subunits α and β was found following treadmill training. Taken together, these results suggest that the upregulation of genes associated with neurite and AChR regeneration following treadmill training may contribute to enhanced gastrocnemius strength recovery following BoNT-A injection.

Suture boots: an aid for the injection of onabotulinum toxin a for primary focal hyperhidrosis

Primary focal hyperhidrosis is a difficult problem for adults, children, and adolescents, causing significant impairment in quality of life. Onabotulinum toxin A injection is an effective third-line treatment for primary focal hyperhidrosis. Here we describe a technique to ensure adequate depth of botulinum toxin placement in the dermis using suture boots as an aid for injection.

A single injection of botulinum toxin decreases the margin of safety of neurotransmission at local and distant sites

BACKGROUND

We tested the hypothesis that a single injection of botulinum toxin not only has local, but also distant effects on muscle function, biochemistry, and pharmacodynamics of atracurium.

METHODS

Botulinum toxin (2.5 U) was injected into the tibialis muscle of anesthetized rats (n = 26). The contralateral side with no injection served to study distant effects. Control animals (n = 25) received a saline injection. Neuromuscular function, pharmacology, and expression of acetylcholine receptors (nAChRs) were evaluated in the tibialis at 0, 4, and 16 days after injection and in comparison with saline- injected controls.

RESULTS

On day 4, botulinum toxin caused complete paralysis of the tibialis, while its contralateral side showed a decrease in absolute twitch tension (1.8 N [1.6; 1.9] vs 3.0 N [2.8; 3.1], Newton, P < 0.05). On day 16, muscle weakness was only present on the toxin-injected side where absolute twitch tension was decreased (0.6 N [0.6, 0.7] vs 3.4 N [3.1, 3.7], P < 0.05). Tibialis mass was decreased on the toxin-injected side at day 4 (1.46 mg/g [1.43, 1.48] vs 1.74 mg/g [1.72; 1.75], P < 0.05) and on day 16 (0.78 mg/g [0.76, 0.79] vs 1.73 mg/g [1.69; 1.77], P < 0.05). Effects distant from the site of injection were seen on day 16, when muscle atrophy was also present in the adjacent gastrocnemius and soleus muscles. Normalized to tibialis mass, specific twitch tension (tension/g muscle) was reduced on the contralateral side at day 4 and on the toxin-injected side at day 16 in relation to saline controls. At day 16, an increased sensitivity to atracurium was seen on the toxin-injected side, evidenced as a decreased ED(50) (0.23 mg/kg [0.13, 0.33] vs 0.72 mg/kg [0.63, 0.82], P < 0.05) and a lower infusion rate (38 μL/kg/min [32, 43] vs135 μL/kg/min [126, 144], P < 0.05), together with a reduced plasma concentration requirement of atracurium (0.5 μg/mL [0.4, 0.7] vs 4.5 μg/mL [3.8, 5.2], P < 0.05) to achieve a steady state 50% reduction in baseline (absolute) twitch tension. ED(50) of atracurium was also decreased on the contralateral side at day 16 in relation to saline controls. The nAChRs in the tibialis were increased on the toxin-injected side to 123 fmol/mg [115, 131] vs 28 fmol/mg [25, 29] (P < 0.05) in time-matched saline-injected controls at day 4 and to 378 [341, 413] vs 27 fmol/mg [25, 29] (P < 0.05) at day 16.

CONCLUSIONS

Botulinum toxin has local and distant effects on muscle. The decrease in specific twitch tension indicates that the muscle atrophy alone cannot explain the functional changes; neuromuscular transmission is also impaired. An increased sensitivity to atracurium on the toxin-injected side, despite up-regulation of nAChRs, seems unique to botulinum toxin.

[Hyperhidrosis of childhood and adolescence: clinical aspects and therapeutic options]

Hyperhidrosis is characterized by localized or general excessive sweating which is severe enough to be perceived as pathological. Since excessive sweating often starts in childhood and adolescence, usually in children between 6 and 16 years of age, hyperhidrosis is an important disorder for children and juveniles. This condition causes considerable disruption of both social life and educational career, leading to severe deterioration in the patient's quality of life. In addition, therapy is often challenging since many treatment modalities are not approved for children. Nonetheless, there are still effective therapeutic options for children with hyperhidrosis.

Therapeutic effectiveness of botulinum toxin type A based on severity of palmar hyperhidrosis

A dose of 60 units (U) of botulinum toxin type A (BT-A) has been confirmed to have efficacy for patients with palmoplantar hyperhidrosis. However, the effectiveness of this dose is limited in severe cases defined as sweat production of 2 mg/cm(2) per min or more (measured by the ventilated capsule method) and a Hyperhidrosis Disease Severity Scale (HDSS) grade of 3 or 4. An increased dose of 90 U of BT-A was found to reduce sweating for approximately 7 months. In a comparison of patients with sweat production of more than 2.5 mg/cm(2) per min and an HDSS grade of 4 and patients with sweat production of 2.5 mg/cm(2) per min or less and an HDSS grade of 3, there was no difference in the reduction of sweat production at 5 months, but the duration of the reduced sweating was shorter for the former group. This suggests that there are limits to the efficacy of BT-A for severe forms of the disease with sweat production of more than 2.5 mg/cm(2) per mL.

Botulinum neurotoxin-A does not spread to distant muscles after intragastric injection: A double-blind single-fiber electromyography study

The purpose of this study was to perform a careful neurophysiological examination to identify subclinical signs of botulinum toxin spread distant to the injection site following intragastric injection for obesity treatment. Single-fiber electromyography of extensor digitorum communis and repetitive stimulation of abductor digiti minimi were performed before and 8 days after multiple intragastric injections of botulinum toxin A (Botox, 200 U per patient) or placebo. The study was performed in a randomized double-blind fashion. No patient in either group displayed results indicative of neuromuscular dysfunction either before or after the treatment. No significant change in muscle jitter was observed when comparing baseline with the after-treatment evaluation in either group, and no significant differences between groups were observed. After intragastric botulinum toxin injection no subclinical sign of distant spread was observed.

Botulinum toxin for hyperhidrosis: a review

Primary focal hyperhidrosis is a disorder of idiopathic excessive sweating that typically affects the axillae, palms, soles, and face. The disorder, which affects up to 2.8% of the US population, is associated with considerable physical, psychosocial, and occupational impairments. Current therapeutic strategies include topical aluminum salts, tap-water iontophoresis, oral anticholinergic agents, local surgical approaches, and sympathectomies. These treatments, however, have been limited by a relatively high incidence of adverse effects and complications. Non-surgical treatment complications are typically transient, whereas those of surgical therapies may be permanent and significant. Recently, considerable evidence suggests that botulinum toxin type A (BTX-A) injections into hyperhidrotic areas can considerably reduce focal sweating in multiple areas without major adverse effects. BTX-A has therefore shown promise as a potential replacement for more invasive treatments after topical aluminum salts have failed. This article reviews the epidemiology, diagnosis, and management of primary focal hyperhidrosis, with an emphasis on recent research evidence supporting the use of BTX-A injections for this indication.

Botulinum toxin type A reduces histamine-induced itch and vasomotor responses in human skin

BACKGROUND

Clinical evidence has revealed the antipruritic effect of botulinum toxin type A (BoNT/A). BoNT/A is believed to be effective against itch as it inhibits the release of acetylcholine as well as some other substances that may be involved in itch.

OBJECTIVES

To investigate the effect of subcutaneous administration of BoNT/A on experimentally histamine-induced itch in human skin.

METHODS

In this double-blind, placebo-controlled study, 14 healthy men (mean +/- SD age 26.3 +/- 2.6 years) received BoNT/A (Botox; Allergan, Irvine, CA, U.S.A.; 5 U) and isotonic saline on the volar surface of either forearm. Histamine prick tests were performed four times at the treatment sites (before treatment, and days 1, 3 and 7 after treatment). The itch intensity (as rated on a 0-10 visual analogue scale), itch area, neurogenic inflammation (visible flare area), blood flow (laser Doppler) and cutaneous temperature (thermographic images) were measured over the course of the trials.

RESULTS

BoNT/A reduced the histamine-induced itch intensity (F(1,39) = 30.2, P < 0.001) and itch area (F(1,39) = 8.8, P = 0.011) compared with saline at all time points after treatment. The duration of itch was also shorter for BoNT/A-treated areas (F(1,39) = 19.4, P < 0.001), with a peak effect at day 7. The flare area was smaller in the BoNT/A-treated arm compared with the saline-treated arm at all time points after treatment (F(1,39) = 15.4, P = 0.002). Findings from blood flow (F(1,26) = 177.3, P < 0.001) and temperature measurements (F(1,26) = 27.6, P < 0.001) clearly showed the suppressive effect of BoNT/A on vasomotor reactions, with the maximal effect on days 3 and 7.

CONCLUSIONS

BoNT/A reduced the itch intensity, blood flow and neurogenic inflammation in response to the histamine prick test in human skin. The findings could be applicable in the treatment of some pruritic conditions that can be difficult to treat with conventional treatments.

NeuroBloc/Myobloc: unique features and findings

This review outlines factors that differentiate botulinum toxin serotypes and focuses on the unique features of the commercially available form of BoNT-B (i.e., Myobloc/NeuroBloc). A series of preclinical studies in Cynomolgus monkeys are reviewed. Each of these studies used electrophysiologic measures of changes in the compound muscle action potential (CMAP) following supramaximal nerve stimulation to evaluate the direct effects of the toxin in the injected muscle, as well as the spread of the effects to non-injected muscles. The results of 14 studies were summarized, including several that compared the effects of equivalent doses of BoNT-A and BoNT-B injected into muscles on the opposite side of the same monkey. There is clear evidence that when equivalent doses of BoNT-A and BoNT-B are assessed, there is greater spread to both nearby and remote non-injected muscles associated with BoNT-A. Similar studies in the mouse model demonstrated that high, but non-lethal, doses of BoNT-A unilaterally injected into the foot resulted in spread of the effects across the midline to the opposite non-treated foot, while there was no evidence of bilateral effects with equivalent unilateral injections of BoNT-B. Finally, this review summarizes a series of studies in the trapezius and gastrocnemius muscles of monkeys demonstrating that when doses producing equivalent initial effects of BoNT-A and BoNT-B are compared, the duration of effects and the time course of recovery are almost identical across toxins.

Subcutaneous Botulinum toxin type A reduces capsaicin-induced trigeminal pain and vasomotor reactions in human skin

The present human study aimed at investigating the effect of subcutaneous administration of Botulinum toxin type A (BoNT/A) on capsaicin-induced trigeminal pain, neurogenic inflammation and experimentally induced cutaneous pain modalities. Fourteen healthy males (26.3+/-2.6 years) were included in this double-blind and placebo-controlled trial. The subjects received subcutaneous BoNT/A (22.5U) and isotonic saline in the mirror sides of their forehead. Pain and neurogenic inflammation was induced by four intradermal injections of capsaicin (100mug/muL) (before, and days 1, 3 and 7 after treatments). The capsaicin-induced pain intensity, pain area, the area of secondary hyperalgesia, the area of visible flare and vasomotor reactions were recorded together with cutaneous heat, electrical and pressure pain thresholds. BoNT/A reduced the capsaicin-induced trigeminal pain intensity compared to saline (F=37.9, P<0.001). The perceived pain area was smaller for the BoNT/A-treated side compared to saline (F=7.8, P<0.05). BoNT/A reduced the capsaicin-induced secondary hyperalgesia (F=5.3, P<0.05) and flare area (F=10.3, P<0.01) compared to saline. BoNT/A reduced blood flow (F(1,26)=109.5, P<0.001) and skin temperature (F(1,26)=63.1, P<0.001) at the capsaicin injection sites compared to saline and its suppressive effect was maximal at days 3 and 7 (P<0.05, post hoc test). BoNT/A elevated cutaneous heat pain thresholds (F=17.1, P<0.001) compared to saline; however, no alteration was recorded for electrical or pressure pain thresholds (P>0.05). Findings from the present study suggest that BoNT/A appears to preferentially target Cfibers and probably TRPV1-receptors, block neurotransmitter release and subsequently reduce pain, neurogenic inflammation and cutaneous heat pain threshold.

A comprehensive approach to the recognition, diagnosis, and severity-based treatment of focal hyperhidrosis: recommendations of the Canadian Hyperhidrosis Advisory Committee

BACKGROUND

Hyperhidrosis can have profound effects on a patient's quality of life. Current treatment guidelines ignore disease severity.

OBJECTIVE

The objective was to establish clinical guidelines for the recognition, diagnosis, and treatment of primary focal hyperhidrosis.

METHODS AND MATERIALS

A working group of eight nationally recognized experts was convened to develop the consensus statement using an evidence-based approach.

RECOMMENDATIONS

An algorithm was designed to consider both disease severity and location. The Hyperhidrosis Disease Severity Scale (HDSS) provides a qualitative measure that allows tailoring of treatment. Mild axillary, palmar, and plantar hyperhidrosis (HDSS score of 2) should initially be treated with topical aluminum chloride (AC). If the patient fails to respond to AC therapy, botulinum toxin A (BTX-A; axillae, palms, soles) and iontophoresis (palms, soles) should be the second-line therapy. In severe cases of axillary, palmar, and plantar hyperhidrosis (HDSS score of 3 or 4), both BTX-A and topical AC are first-line therapy. Iontophoresis is also first-line therapy for palmar and plantar hyperhidrosis. Craniofacial hyperhidrosis should be treated with oral medications, BTX-A, or topical AC as first-line therapy. Local surgery (axillary) and endoscopic thoracic sympathectomy (palms and soles) should only be considered after failure of all other treatment options.

CONCLUSIONS

These guidelines offer a rapid method to assess disease severity and to treat primary focal hyperhidrosis according to severity.

Treatment of focal hyperhidrosis

BACKGROUND

Focal hyperhidrosis is not rare, affecting over 2.5% of the population. This condition is often socially and professionally debilitating, leading to significant quality of life impairment. It most commonly involves the axillae, palms, soles, and face.

OBJECTIVE

To review hyperhidrosis and discuss and compare the treatment options currently available.

CONCLUSIONS

Topical or systemic therapies may be helpful for patients with mild disease. Invasive surgical options, although often effective, are limited by complications. More recently, botulinum toxin injection has proven to be a safe and successful treatment for hyperhidrosis and results in high patient satisfaction. Botulinum toxin A (Botox, Allergan Inc., Irvine, CA) is currently approved in the United States, Canada, the United Kingdom, and many other countries for the treatment of axillary hyperhidrosis and is routinely used off-label for other anatomic sites.

Complications With the Use of Botulinum Toxin Type A for Cosmetic Applications and Hyperhidrosis

In dermatology, botulinum toxin is now most often used to reduce dynamic facial creases and treat primary focal hyperhidrosis. The exemplary safety record of this medication is such that after nearly 2 decades, it is not known to have any long-term adverse events. Transient adverse events, such as mild injection pain, are typically minor and spontaneously remitting. Headache, nausea and flu-like symptoms, lid and brow ptosis after upper face injection, lower face asymmetry after perioral injection, and fine motor impairment after palmar injection are uncommon to rare. Understanding of anatomic landmarks and site-specific precautions can further mitigate the incidence of unwanted effects. Patients who do experience uncommon, transient effects can be reassured that these are not dangerous and will resolve completely without intervention.

Diagnosis, Impact, and Management of Focal Hyperhidrosis: Treatment Review Including Botulinum Toxin Therapy

Idiopathic localized hyperhidrosis, called for hyperhidrosis, affects almost 3% of the US population. The most frequent anatomic sites of involvement include the axillae, palms, soles, and face. For those affected, this condition can be extremely socially debilitating and interfere with work activities. Until recently, frequently ineffective topical regimens or problematic surgical procedures have been the treatments of choice. Since 1996, intracutaneous injections of botulinum toxin have been used as a minimally invasive treatment for this condition with numerous studies documenting safety, efficacy, and extremely high levels of patient satisfaction. Botulinum toxin type A (Botox) was approved by the US Food and Drug Administration in 2004 for the treatment of axillary hyperhidrosis.

Evaluation of objective methods to diagnose palmar hyperhidrosis and monitor effects of botulinum toxin treatment

OBJECTIVE

To evaluate (1) if laboratory tests may be a useful complement in diagnosing palmar hyperhidrosis and (2) if such tests can be used in the follow up examination of treatment effects.

METHODS

Repeated measurements of evaporation and conductance were made in glabrous skin on hands and compared with subjective estimates of the degree of sweating in 20 control subjects and 20 patients with a history of palmar hyperhidrosis. In addition, 17 patients were monitored for up to 6 months after treatment of the hands with botulinum toxin A.

RESULTS

Before treatment, evaporation in the palms was higher in the patients than in the control subjects but skin conductance did not differ between the groups. After treatment both evaporation and skin conductance decreased markedly in the patients and then slowly returned towards pretreatment values.

CONCLUSIONS

Measurements of evaporation, but not skin conductance, may be a useful objective adjunct when diagnosing palmar hyperhidrosis. Both methods can, however, be used to monitor intraindividual changes of sweating over time.

Current Therapeutic Options for Treating Primary Hyperhidrosis

Severe hyperhidrosis can cause extreme embarrassment that may lead to social and professional isolation. Therapeutic strategies to hyperhidrosis should employ the least invasive treatment that provides effective symptom control. The treatment options available for control of hyperhidrosis, non-surgical or surgical, differ in their invasiveness and efficacy. Mechanisms of action of antiperspirants, iontophoresis, cholinergic inhibitor drugs, botulinum toxin, and surgical sympathectomy are reviewed. There is little published evidence in the form of comparative randomised trials to support the use of one treatment over another. However, authors have tended to recommend those therapies that are available to their speciality. Specific therapies should be tailored to the patient's symptoms to gain maximum symptomatic improvement with minimum invasiveness and side-effects. To achieve this, the full range of treatment options should be available to, or accessible by the consulting doctor in order for the patient to have a meaningful choice.

Management of primary hyperhidrosis: a summary of the different treatment modalities

Hyperhidrosis is a common and distressing condition involving increased production of sweat. A variety of treatment modalities are used to try to control or reduce sweating. Sweat is secreted by eccrine glands innervated by cholinergic fibers from the sympathetic nervous system. Primary hyperhidrosis most commonly affects palms, axillae and soles. Secondary hyperhidrosis is caused by an underlying condition, and treatment involves the removal or control of this condition. The treatment options for primary hyperhidrosis involve a range of topical or systemic medications, psychotherapy and surgical or non-surgical invasive techniques. Topical antiperspirants are quick and easy to apply but they can cause skin irritation and have a short half life. Systemic medications, in particular anticholinergics, reduce sweating but the dose required to control sweating can cause significant adverse effects, thus, limiting the medications' effectiveness. Iontophoresis is a simple and well tolerated method for the treatment of hyperhidrosis without long-term adverse effects; however, long-term maintenance treatments are required to keep patients symptom free. Botulinum toxin A has emerged as a treatment for hyperhidrosis over the past 5-6 years with studies showing good results. Unfortunately, botulinum toxin A is not a permanent solution, and patients require repeat injections every 6-8 months to maintain benefits. Psychotherapy has been beneficial in a small number of cases. Percutaneous computed tomography-guided phenol sympathicolysis achieved good results but has a high long-term failure rate. Surgery has also been shown to successfully reduce hyperhidrosis but, like other therapies, has several complications and patients need to be informed of these prior to undergoing surgery. The excision of axillary sweat glands can cause unsightly scarring and transthoracic sympathectomy (either open or endoscopic) can be associated with complications of compensatory and gustatory hyperhidrosis, Horner syndrome and neuralgia, some of which patients may find worse than the condition itself.

Physiological effects of botulinum toxin in spasticity

There is considerable evidence that injection of botulinum toxin (BTX) into muscles with spastic overactivity reduces resistance to passive movement in joints supplied by the injected muscles. The demonstration of improvement in active performance of the paretic limbs has been only anecdotal to date, and represents the most difficult challenge in research on BTX therapy in spastic paralysis. Data are reviewed that indicate several neurophysiological actions of BTX, other than the blocking of acetylcholine release at the neuromuscular ending: effects on the central nervous system, including retrograde axonal transport, reduced motoneuronal excitability, action on central synapses such as decreased Renshaw inhibition and increased presynaptic inhibition; action on gamma motoneuronal endings; action on most active terminals; spread of BTX to neighboring muscles; spread of BTX effects to remote muscles. Several of these neurophysiological actions are likely to contribute to improvement in active movements, as they may antagonize the primary mechanisms of functional impairment in patients with spastic paralysis: weakness, spastic cocontraction, spastic dystonia, and muscle shortening. We review the evidence for reduction of spastic cocontraction in both the injected muscle and its antagonist, and for improvement of antagonist weakness after BTX injection. The capacity of intramuscular BTX to reduce spastic dystonia and lengthen shortened muscles is also discussed based on prior literature. When injected into the more overactive of a pair of spastic antagonists around a joint, BTX should affect all the main mechanisms impairing active function around the joint.

Treatment of hyperhidrosis and drooling with botulinum exotoxin

The treatment of focal hyperhidrosis and drooling with neurolysis of the neuroglandular junction is a relatively new and useful technique for managing such obvious conditions and improving the patient's quality of life. The treatment is safe, minimally invasive, and an effective alternative to other treatment modalities.

Treatment of hyperhidrosis with botulinum toxin

Focal hyperhidrosis is a common problem that affects up to 2.8% of the population with significant psychosocial implications. Traditional therapies have not proven effective for most of these patients, which further adds to patient anxiety. Botulinum toxin is emerging as a novel treatment for focal hyperhidrosis and is proving to be safe and effective. A therapeutic protocol for focal hyperhidrosis includes an individualized treatment plan for each site of involvement. For those who are affected in the palms and soles, the most common treatments include topical treatment with aluminum chloride, iontophoresis, botulinum toxin,systemic medications, and sympathectomy. For those who have axillary focal hyperhidrosis, iontophoresis is often difficult and botulinum toxin becomes the second line therapy. As of June 2003, BTX A has been approved for the treatment of hyperhidrosis in 13 countries: England, Canada, New Zealand, Australia, Taiwan, Netherlands, Switzerland, Brazil, Argentina, Columbia, El Salvador, Guatemala, and Mexico. With the currently available literature and ongoing studies, it should only be a short time before the U.S. Food and Drug Administration approves botulinum toxin therapy for focal hyperhidrosis in the United States.

Treatment of dyshidrotic hand dermatitis with intradermal botulinum toxin

BACKGROUND

Botulinum toxin (Btx A) has recently been used in the treatment of focal hyperhidrosis. Hyperhidrosis is also an aggravating factor in nearly 40% of patients with dyshidrotic hand eczema.

OBJECTIVE

The objective of this study was to evaluate the effect of intradermal injections of Btx A on dermatitis in patients with vesicular hand dermatitis.

METHODS

Ten patients with vesicular dermatitis were treated on one hand with intradermal Btx A (mean, 162 U BOTOX, Allergan Pharmaceuticals, Irvine, Calif) with the untreated side as a control.

RESULTS

Self-assessment at follow-up 5 to 6 weeks after injection on a 5-point scale (none, slight, moderate, good, or very good effect) showed that 7 of 10 patients experienced good or very good effect. A decrease in itching was shown with a visual linear analogue scale (VAS) for itching, with mean 39% on the treated side compared with an increase by 52% on the untreated side. These findings were supported by the evaluation of clinical signs. Six of 7 patients who experienced good or very good effect also had aggravating hand sweating or worsening during the summer.

CONCLUSION

Btx A can be a valuable alternative for patients with treatment-refractory hand eczema of the vesicular type, especially with hyperhidrosis or worsening during the summer.