Botulinum A exotoxin in cosmetic dermatology

Unusual herpetic reactivation in a young female following botox injection: a case report study

BACKGROUND

Botox injections are commonly used for cosmetic and therapeutic purposes because they temporarily paralyze muscles, reduce wrinkles, and alleviate certain medical conditions. Although generally considered safe and effective, Botox injections may cause potential complications. While herpes reactivation is more commonly associated with immunosuppressive therapies, such as chemotherapy or corticosteroid use, its association with Botox injection is poorly documented.

CASE PRESENTATION

A 33-year-old woman presented with progressive painful rashes and vesicles on her forehead, scalp, and right upper eyelid, accompanied by fever and malaise following a Botox injection to treat wrinkles. A positive Tzanck smear test result confirmed the diagnosis of herpes infection. The patient was treated with antiviral medication, and her symptoms gradually regressed over several days.

CONCLUSIONS

Although herpes reactivation is more commonly associated with immunosuppressive therapies, few cases of herpes zoster and herpes simplex following Botox injection have been reported. The pathogenesis of herpes reactivation following Botox injection is unclear; however, it has been hypothesized that the Botox protein is a potent antigen that may activate the cellular immune system, making it easier for the virus to reactivate. Healthcare providers should be aware of this potential complication and consider it when evaluating patients who present with painful rashes following Botox injections. In addition, individuals who want to receive Botox injections should be informed of this complication. The diagnosis of herpetic infection should be made promptly, and antiviral therapy should be initiated to minimize the risk of complications. Further research is needed to better understand the pathogenesis and risk factors for herpes following Botox injection and to develop strategies for preventing and managing this complication.

Toxic potential of botulinum toxin type A on senescence in a Drosophila melanogaster model

Botulinum toxin type-A (BoNT/A) application, especially neurological disorders, has been spread nowadays while it may cause side effects. The current study aimed to assess the BoNT/A dose-dependent effect on induction of aging in the Drosophila melanogaster model. The third instar larvae of Drosophila melanogaster were exposed to ¼ LC₅₀, ½ LC₅₀, and LC₅₀ of BoNT/A in the Drosophila diet for 48 h while H₂O₂ 1% was used as a positive control. After the exposure time, some larvae were collected for molecular study, including gene expression analysis, comet assay, oxidative stress markers, and the phenotype changes. BoNT/A induced dose-dependent cytotoxicity, elevated reactive oxygen species (ROS) levels, and superoxide dismutase (SOD) enzyme activity. In addition, it caused DNA damage and activated caspase-3 and -9, and reduced the body size of the fly, especially in high doses. In line with the purpose of the study, aging markers, including β-galactosidase (β-gal), p16, p21, p38, and p53, were up-regulated by BoNT/A low dose. BoNT/A activates the aging pathway in the low dose, and increasing the dose induces toxicity, including oxidative stress, DNA damage, and apoptosis.

A Study of Botulinum Toxin A for Ultraviolet-Induced Hyperpigmentation: A Randomized Controlled Trial

BACKGROUND

Ultraviolet (UV) exposure contributes to skin hyperpigmentation. Recently, botulinum neurotoxin type A (BoNT-A) showed a promising protective effect on UVB-induced hyperpigmentation in both in vitro and animal models.

OBJECTIVE

The study aimed to investigate the preventive effect of BoNT-A against UVB-induced hyperpigmentation in human subjects.

MATERIALS AND METHODS

A prospective, double-blinded, randomized controlled trial was performed in 15 healthy participants. Four separate square areas on the abdomen were randomly injected intradermally with different dilutions of BoNT-A (1:2.5, 1:5, 1:7.5) and normal saline (control). Two weeks after injection, hyperpigmented spots were induced by UVB irradiation at the experimental sites. The lightness index and hyperpigmentation scores from blinded physician and participants were evaluated.

RESULTS

Fifteen participants completed the study. One week after UVB irradiation, all BoNT-A-treated sites had a significantly lower degree of hyperpigmentation than the control site in lightness index and hyperpigmentation scores from blinded physician and participants (p < .05). However, no statistically significant difference was observed between different concentrations of BoNT-A. No side effects were observed throughout the study period.

CONCLUSION

Intradermal BoNT-A injection provided a protective effect from UVB-induced hyperpigmentation. It may be used for other hyperpigmentation disorders that are aggravated by UVB.

Botulinum toxin (Botox) A for reducing the appearance of facial wrinkles: a literature review of clinical use and pharmacological aspect

Background: Botulinum toxin (Botox) consists of 7 types of neurotoxins; however, only toxins A and B are used clinically. Botox A is used for several disorders in the field of medicine, particularly in dermatology, for cosmetic purposes. It is produced by the bacterium Clostridium botulinum and can be used as a treatment to reduce the appearance of wrinkles in the upper areas of the face, elevate the eyebrows and treat problems such as hyperhidrosis, lichen simplex, pompholyx (dyshidrotic eczema) and acne vulgaris.

Objectives: This article provides a literature review regarding the general issue of Botox as a treatment for reducing facial wrinkle.

Discussion: Botox works by blocking the release of acetylcholine, resulting in paralysis of the local muscles, which usually occurs 24 hrs to two weeks following Botox injection. This effect will last three to six months. The optimal dose of cosmetic Botox in dermatology is 20 units. Botox is relatively safe and does not result in any adverse side effects. However, in certain circumstances, the effect of Botox will gradually resolve, resulting in reduced muscle paralysis over time.

Conclusion: Botox is good and safe medicine to reduce the appearance of facial wrinkles.

Botulinum Neurotoxin Diversity from a Gene-Centered View

Botulinum neurotoxins (BoNTs) rank amongst the most potent toxins known. The factors responsible for the emergence of the many known and yet unknown BoNT variants remain elusive. It also remains unclear why anaerobic bacteria that are widely distributed in our environment and normally do not pose a threat to humans, produce such deadly toxins. Even the possibility of accidental toxicity to humans has not been excluded. Here, I review the notion that BoNTs may have specifically evolved to target vertebrates. Considering the extremely complex molecular architecture of the toxins, which enables them to reach the bloodstream, to recognize and enter neurons, and to block neurotransmitter release, it seems highly unlikely that BoNT toxicity to vertebrates is a coincidence. The carcass⁻maggot cycle provides a plausible explanation for a natural role of the toxins: to enable mass reproduction of bacteria, spores, and toxins, using toxin-unaffected invertebrates, such as fly maggots, as the vectors. There is no clear correlation between toxigenicity and a selective advantage of clostridia in their natural habitat. Possibly, non-toxigenic strains profit from carcasses resulting from the action of toxigenic strains. Alternatively, a gene-centered view of toxin evolution would also explain this observation. Toxin-coding mobile genetic elements may have evolved as selfish genes, promoting their own propagation, similar to commensal viruses, using clostridia and other bacteria as the host. Research addressing the role of BoNTs in nature and the origin of toxin variability goes hand in hand with the identification of new toxin variants and the design of improved toxin variants for medical applications. These research directions may also reveal yet unknown natural antidotes against these extremely potent neurotoxins.

Botulinum neurotoxin formulations: overcoming the confusion

Botulinum toxin A is produced by anaerobic spore-forming bacteria and is used for various therapeutic and cosmetic purposes. Botulinum toxin A injections are the most popular nonsurgical procedure worldwide. Despite an increased demand for botulinum toxin A injections, the clinical pharmacology and differences in formulation of commonly available products are poorly understood. The various products available in the market are unique and vary in terms of units, chemical properties, biological activities, and weight, and are therefore not interchangeable. For safe clinical practice and to achieve optimal results, the practitioners need to understand the clinical issues of potency, conversion ratio, and safety issues (toxin spread and immunogenicity). In this paper, the basic clinical pharmacology of botulinum toxin A and differences between onabotulinum toxin A, abobotulinum toxin A, and incobotulinum toxin A are discussed.

Structure of the BoNT/A1--receptor complex

Botulinum neurotoxin A causes botulism but is also used for medical and cosmetic applications. A detailed molecular understanding of BoNT/A--host receptor interactions is therefore fundamental for improving current clinical applications and for developing new medical strategies targeting human disorders. Towards this end, we recently solved an X-ray crystal structure of BoNT/A1 in complex with its neuronal protein receptor SV2C. Based on our findings, we discuss the potential implications for BoNT/A function.

Molecular dynamics simulations of wild type and mutants of botulinum neurotoxin A complexed with synaptic vesicle protein 2C

Using molecular dynamics simulations, we investigate the relationship between the conformational changes of BoNT/A-RBD:SV2C-LD and the interfacial interactions.

Botulinum neurotoxins: new questions arising from structural biology

Botulinum neurotoxins (BoNTs) are the most toxic substances known and cause botulism in vertebrates. They have also emerged as effective and powerful reagents for cosmetic and medical applications. One important prerequisite for understanding BoNT function in disease, and the further development of the toxins for cosmetic and medical applications, is a detailed knowledge of BoNT interactions with non-toxic neurotoxin-associated proteins and cell surface receptors. Based on the substantial recent progress in obtaining high-resolution crystal structures of key BoNT complexes, we summarize the major advances in understanding BoNT interactions and discuss the resulting potential implications, in particular those relating to BoNT serotype A.

Structural basis for recognition of synaptic vesicle protein 2C by botulinum neurotoxin A

Botulinum neurotoxin A (BoNT/A) belongs to the most dangerous class of bioweapons. Despite this, BoNT/A is used to treat a wide range of common medical conditions such as migraines and a variety of ocular motility and movement disorders. BoNT/A is probably best known for its use as an antiwrinkle agent in cosmetic applications (including Botox and Dysport). BoNT/A application causes long-lasting flaccid paralysis of muscles through inhibiting the release of the neurotransmitter acetylcholine by cleaving synaptosomal-associated protein 25 (SNAP-25) within presynaptic nerve terminals. Two types of BoNT/A receptor have been identified, both of which are required for BoNT/A toxicity and are therefore likely to cooperate with each other: gangliosides and members of the synaptic vesicle glycoprotein 2 (SV2) family, which are putative transporter proteins that are predicted to have 12 transmembrane domains, associate with the receptor-binding domain of the toxin. Recently, fibroblast growth factor receptor 3 (FGFR3) has also been reported to be a potential BoNT/A receptor. In SV2 proteins, the BoNT/A-binding site has been mapped to the luminal domain, but the molecular details of the interaction between BoNT/A and SV2 are unknown. Here we determined the high-resolution crystal structure of the BoNT/A receptor-binding domain (BoNT/A-RBD) in complex with the SV2C luminal domain (SV2C-LD). SV2C-LD consists of a right-handed, quadrilateral β-helix that associates with BoNT/A-RBD mainly through backbone-to-backbone interactions at open β-strand edges, in a manner that resembles the inter-strand interactions in amyloid structures. Competition experiments identified a peptide that inhibits the formation of the complex. Our findings provide a strong platform for the development of novel antitoxin agents and for the rational design of BoNT/A variants with improved therapeutic properties.

Gummy smile and botulinum toxin: a new approach based on the gingival exposure area

BACKGROUND

Gummy smile (GS) is an aesthetic disorder for some patients, which can be corrected by injection of botulinum toxin.

OBJECTIVE

We sought to classify GS according to the area of gingival exposure and the respective muscles involved in order to perfect the botulinum toxin injection technique for each patient.

METHODS

Sixteen patients with GS were evaluated before receiving botulinum toxin injections. Based on the area of excessive gum displayed and identification of the muscles involved, 4 different types of GS were identified: anterior, posterior, mixed, and asymmetric. AbobotulinumtoxinA (Dysport, Ipsen Biopharm Limited, Wrexham, UK) was injected using a different injection technique for each type of GS, based on the main muscles involved. With the aid of two computer programs, the area of gum exposed was measured before and after the application of abobotulinumtoxinA, to evaluate the level of improvement.

RESULTS

There was a decrease in the degree of gum display in all patients. The general average improvement achieved was 75.09%. Two patients showed slight adverse effects that were easily corrected with additional doses of abobotulinumtoxinA.

LIMITATIONS

For this study, there was no sample size calculation and no statistical analysis of the cases.

CONCLUSION

The authors conclude that it is important to identify the type of GS and therefore the main muscles involved, so that the correct injection technique can be used. AbobotulinumtoxinA was shown to be effective and safe for use in all types of GS in the present sample.

Cosmetic treatments: an emerging field of interest for interventional radiologists

The current trend in medical care in the 21st century is evolving into a minimally invasive specialty. The interest of Interventional Radiology (IR) in cosmetic is increasing particularly for outsetting patients, in the treatment of soft tissue vascular malformations, us-guided injections of Botox and varicous veins management. Advantages of cosmetic IR treatments are many: treatments takes less than an hour and provides immediate relief of symptoms; no scaring, because the procedure does not require a surgical incision; an immediate return to normal activity with little or no pain; and high success rate and low recurrence rate compared to surgery.

Novel topical BoNTA (CosmeTox, toxin type A) cream used to treat hyperfunctional wrinkles of the face, mouth, and neck

BACKGROUND

This study aimed to compare the effect of the stabilized novel topical botulinum neurotoxin type A (BoNTA) cream (CosmeTox) and a placebo cream on subjects, to compare clinician-reported outcomes, and to assess the safety and utility of the novel topical BoNTA cream for treating the entire upper face, chin, and neck areas.

METHODS

This study randomized 40 female subjects to receive either topical BoNTA (CosmeTox) cream (2 U/ml) or an identical placebo cream (without BoNTA) on the face, chin, and neck areas. The subjects were followed for 12 weeks. The main outcome measures were the Facial Line Outcomes questionnaire scores and results from the Self-Perception of Age instrument, which assesses age of appearance relative to actual age.

RESULTS

The BoNTA topical cream (CosmeTox) treatment produced significant improvements in the Facial Lines Outcome scores, which were maintained throughout the study period and lasted more than 3 months. The BoNTA topical cream treatment also reduced the age of appearance for a majority of subjects. The placebo had no effect on any measure. No serious adverse events occurred during the entire study period.

CONCLUSION

Topical treatment with the stabilized BoNTA cream (CosmeTox) to the entire upper facial lines resulted in significantly improved facial features and age appearance, as measured by the subjects and clinicians. The BoNTA cream (CosmeTox) resulted in a significantly younger, more satisfying, relaxed appearance.

The use of Botox in interventional radiology

Botox (Botulinum toxin A) has wide public recognition as a cosmetic agent. It has also established a firm foothold within the medical community for the treatment of a wide range of myospastic disorders. With imaging guidance, interventional radiologists can deliver this medication to a variety of otherwise difficult to reach targets with high accuracy and with minimal complications. We illustrate the use of Botox in interventional radiology by describing our fluoroscopic technique for the treatment of piriformis syndrome. The key to successful Botox therapy of myospastic disorders is accurate clinical diagnosis. Excellent communication and rapport with the referring clinicians is therefore essential to maximize the likelihood of a successful outcome. The range of services offered by interventional radiologists continues to evolve. With the recent growth of endovenous treatment for varicose veins, some have found it necessary to provide sclerotherapy for spider veins. As patients become accustomed to receiving these cosmetic treatments from interventionalists, they may come to us for advice about other esthetic therapy. The idea of some interventional radiologists adding cosmetic medicine to their practice should, therefore, not seem unreasonable. We illustrate the use of Botox for facial rejuvenation by describing our technique for the treatment of glabelar (frown) lines. Before entering into this type of practice, it is critical to obtain adequate and appropriate training for each cosmetic intervention. If possible, the interventionalist should seek to establish a mentor relationship with someone highly experienced in cosmetic medicine.

[Botulinum toxin and wrinkles: few side effects and effective combining procedures with other treatments]

Chemical denervation, through the biologic effect of botulinum toxin, provides a very effective, low risk, lasting treatment for hyperkinetic wrinkles, mainly of the upper face. Patients with such rhytides, when treated with surgical myotomies or other alternative medical treatments, are at greater risk and with potentially less lasting results. Botulinum toxin has been widely used for the last 20 years in many areas of medicine. It has been used for 13 years in dermatology and plastic surgery, without important complications or sequellae. Any complications appear to be reversible. In these two specialties, with the minute quantities (units) and volume of material injected, complications are infrequent; some of them are now anecdotal. The only main complication from a cosmetic point of view is blepharoptosis, which is more and more rare. Because of a better anatomical knowledge of the affected muscles, and our improved technique, risks are greatly reduced. In our two latest multicenter studies on glabellar wrinkles, between 2002 and 2004, we saw no blepharoptosis. Conversely, in case of dynamic wrinkles associated with muscle, fat, and skin relapse, and/or deep furrows, only surgical procedures and/or other surface treatments are effective. Botulinum toxin injections are not meant to replace upper, mid, or mandibular face and neck lifts; indeed, botulinum toxin injections may optimize results from these surgical procedures. These injections play a fundamental process in producing long lasting results. The current and future evolution, in cosmetic surgery, is toward full achieved, but focused, natural, and minimally invasive surgical procedures in combination with effective and minimal risk techniques such as the botulinum toxin injections. To optimize the effect of the medical procedures, botulinum toxin should be injected three weeks before surgery. In addition botulinum toxin injections may optimize and prolong the effect of the surface procedures, as lasers, peels and fillers. This medicosurgical combination is one of the examples that best describes the evolution of plastic and aesthetic surgery in 2004.

Dysport

Since the commercial launch of Dysport in 1991, after 10 years of clinical studies on its predecessor formulations, this BTX-A product has shown great therapeutic promise with a good safety profile and low incidence of treatment failures. As with all BTX products, Dysport should not be seen as a generic equivalent but as a specific product with individual unit dosing requirements and side effect profiles. Its role as an important BTX-A molecule looks set to expand as new indications for botulinum toxin arise, and as the cosmetic usage of Dysport is approved in countries outside of South America.

Type A botulinum toxin in the upper aspect of the face

The use of botulinum toxin type A (BTX-A) for facial rejuvenation was first systematically developed by Carruthers and Carruthers on the upper aspect of the face. In the early 1990s, the first studies of the cosmetic use of BTX-A were published. BTX-A was only approved in 2002, however, by the U.S. Food and Drug Administration when extensive cosmetic studies were evaluated. The treatment of facial wrinkles with BTX-A has truly changed the concepts held by physicians regarding facial rejuvenation, mainly on the upper aspect of the face. It is one of the most common cosmetic procedures currently performed by physicians.

Botulinum toxin in the lower one third of the face

The use of botulinum toxin (BTX) in the lower one third of the face has rapidly become one of the most popular ways to rejuvenate the face, due to the effectiveness of BTX in this area and the lack of major side effects. It is recommended that physicians planning on treating patients in this area of the face first have extensive experience treating the more traditional areas, such as the forehead, glabella, or crow's feet, because the inferior one third of the face has many co-dependent and interdigitating (interrelated) muscles that are very sensitive and readily affected by minimal amounts of BTX. We prefer to reconstitute a 100-U vial of Botox(R) with 1-2.5 mL of saline solution because some of the muscles in this area of the face are very sensitive to diffusion of the toxin and will be weakened beyond the area originally planned for treatment.

[Skin, wrinkles and botulinum toxin]

OBJECTIVE

To present an up-to-date analysis about the use of botulinum toxin for treating facial lines and wrinkles.Method. - A systematic search of the literature was conducted to select the most recent or relevant publications on this topic, through Medline.

RESULTS

Out of the 583 articles retrieved, 90 were finally selected for the study.

DISCUSSION

Validity of using botulinum toxin for cosmetic use is demonstrated, together with contra-indications and different methods to objectivate the results. The different available types of toxin are presented and compared. Modalities of preparation, conservation, and waste disposal are detailed. Anatomical bases of muscular facial balance are reviewed, with techniques of injection presented for each site, and also with adjunctive procedures. Complications and side effects are described and analysed. Most complications can be prevented through: perfect knowledge of local anatomy;use of small volumes;orientation of the needle bevel towards the muscle body, injection within the muscle body if thick, more superficial if thin;application of ice on the skin pre- and post-injecting. Adding epinephrin or diluting with xylocaïne and epinephrin is not commonly used.

CONCLUSION

Botulinum toxin has found its way as a major component of the therapeutic armamentarium. Its efficacy for facial rejuvenation has made it extremely popular, but its use does follow strict rules, and should be restricted to soundly trained practitioners.

Multicenter, double-blind study of the efficacy of injections with botulinum toxin type A reconstituted up to six consecutive weeks before application

BACKGROUND

It is recommended that botulinum toxin be used immediately or within 2 weeks after its reconstitution because its efficacy might be compromised by prolonged storage.

OBJECTIVES

To evaluate the efficacy of botulinum toxin type A (BTX-A) reconstituted over 6 consecutive weeks for the treatment of glabellar frown lines.

METHODS

Four vials of BTX-A were reconstituted each of 7 days over a period of 6 weeks, totaling 28 vials, corresponding to seven reconstitution dates. During this period, the BTX-A was stored according to the manufacturer's instructions. On the day after the last reconstitution, all of the reconstituted vials were injected in patients from four dermatologic centers taking part in this study. A total of 88 patients were treated on the same day and were followed every 2 weeks for 4 months. All patients were photographed at all stages. A number of professionals assessed the efficacy of reconstituted BTX-A based on the reduction of the maximum frowning capacity of the treated muscles.

RESULTS

Of the 88 patients who were selected, 3 were excluded. Three forms of evaluation were applied, and no statistically significant differences were found in the results presented.

CONCLUSION

BTX-A may be applied up to 6 weeks after reconstitution without losing its effectiveness. Other factors, which are probably individual, may influence the response to BTX-A injections.

Axillary hyperhidrosis: eccrine or apocrine?

We review the literature regarding axillary hyperhidrosis, discuss normal sweat gland function and postulate on the respective roles of the eccrine, apocrine and apo-eccrine glands in the pathophysiology of excessive axillary sweating.

Review of the use of botulinum toxin for hyperhidrosis and cosmetic purposes

This article reviews the current status of dermatological uses for botulinum toxin type A (Botox), recently approved in the United States for treatment of glabellar wrinkles, and type B (Myobloc), approved for cervical dystonia. The respective formulations of Botox and Myobloc are described, and injection techniques and special considerations for administration in the treatment of dermatologic conditions are also discussed. The use of botulinum toxin injections for cosmetic treatment of movement-related facial lines and platysmal bands in the neck is reviewed, including injection procedures, efficacy, and potential complications. Recent developments in the use of botulinum toxins for the treatment of palmar and axillary hyperhidrosis are also described, comparing type A and type B results. Although direct comparisons between botulinum toxins for dermatologic applications are complicated by the lack of functional equivalence of the standard potency assays, appropriate dosing strategies for obtaining satisfactory clinical results using type B are being established, which will add to the experience already gained with type A. The diffusion characteristics of type B appear to show different and potentially advantageous clinical profiles in the treatment of crows' feet and hyperhidrosis compared with type A.

New indications for botulinum toxin type a in cosmetics: mouth and neck

Botulinum toxin type A is frequently used to smooth hyperkinetic lines in the periocular and forehead areas of the upper face, but it has been used less frequently for indications in the lower face and neck. This study was designed to determine whether botulinum toxin treatment of the mouth and neck areas is as clinically successful as the treatment of the upper face. This was a retrospective study of patients who were treated with botulinum toxin type A (Botox) to soften hyperkinetic facial wrinkles. Of 100 patients randomly selected from a single clinical practice, 91 met the inclusion criteria and were divided into two groups for analysis. The 56 patients in group 1 did not receive treatment in the mouth and neck areas, whereas the 35 patients in group 2 were treated at least once in the mouth and neck areas. Patients were surveyed for periods ranging from 7 to 49 months. Most patients in each group had a single botulinum procedure during this period. Both groups of patients had comparable improvement of wrinkles both at the evaluation immediately after the neuromuscular blockade and during follow-up. In comparison with patients whose treatment was confined to the upper face, patients who received global treatment with botulinum toxin type A, including injections in the mouth and neck areas, were injected in more sites per procedure and had more procedures in combination with other therapies. Patient satisfaction with botulinum toxin treatment and outcomes was high in both groups. Botulinum toxin type A is an important tool within the therapeutic spectrum for the treatment of hyperkinetic facial wrinkles, including those in the areas of the mouth and neck.

Severe, intractable headache after injection with botulinum a exotoxin: report of 5 cases

BACKGROUND

Botulinum A exotoxin is a safe agent in common use in dermatology. Occasionally, patients receiving botulinum toxin injections report postprocedure discomfort, including headaches.

OBJECTIVE

Our purpose was to estimate the rate of severe headaches occurring after injection with botulinum toxin for dermatologic indications.

METHODS

We used prospective monitoring of botulinum toxin injection outcomes in a single-site, 3-dermatologist practice. There was in-office and telephone follow-up of patients experiencing severe headaches.

RESULTS

Approximately 1% of patients (4/320) receiving botulinum A exotoxin injections may experience severe, debilitating headaches. These may persist at high intensity for 2 weeks to 1 month before gradually fading.

CONCLUSION

Botulinum A exotoxin injection may be associated with the development of life-altering headaches. Patients should be informed of this possibility.

Treatment of palmar hyperhidrosis with botulinum toxin

Excessive sweating of the palms, axillae, and soles can be managed with intradermal injections of botulinum toxin as an alternative to more aggressive surgical therapies such as sympathectomy and less effective techniques including topical antiperspirants. The dosage and injection techniques can be optimized to provide several months of freedom from this troubling disorder.