Postmenopausal craniofacial hyperhidrosis treated with botulinum toxin type B

From Toxin to Treatment: A Narrative Review on the Use of Botulinum Toxin for Autonomic Dysfunction

Since its regulatory approval over a half-century ago, botulinum toxin has evolved from one of the most potent neurotoxins known to becoming routinely adopted in clinical practice. Botulinum toxin, a highly potent neurotoxin produced by Clostridium botulinum, can cause botulism illness, characterized by widespread muscle weakness due to inhibition of acetylcholine transmission at neuromuscular junctions. The observation of botulinum toxin's anticholinergic properties led to the investigation of its potential benefits for conditions with an underlying etiology of cholinergic transmission, including autonomic nervous system dysfunction. These conditions range from disorders of the integument to gastrointestinal and urinary systems. Several formulations of botulinum toxin have been developed and tested over time, significantly increasing the availability of this treatment for appropriate clinical use. Despite the accelerated and expanded use of botulinum toxin, there lacks an updated comprehensive review on its therapeutic use, particularly to treat autonomic dysfunction. This narrative review provides an overview of the effect of botulinum toxin in the treatment of autonomic dysfunction and summarizes the different formulations and dosages most widely studied, while highlighting reported outcomes and the occurrence of any adverse events.

Efficacy and Safety of Botulinum Toxin B in Focal Hyperhidrosis: A Narrative Review

Botulinum toxin type B (BoNT-B), known as Myobloc® in the United States and as Neurobloc® in Europe, is a new therapeutically available serotype among the botulinum toxin family. During the last years several data have been reported in literature investigating its efficacy and safety, as well as defining the dosing and application regiments of BoNT-B in the treatment of hyperhidrosis. Moreover, recent studies have been examining its safety profile, which may be different from those known about BoNT-A. The aim of this review is to provide information about what is currently known about BoNT-B in regards to the treatment of focal hyperhidrosis.

Treatment of Hyperhidrosis: An Update

Hyperhidrosis is a dermatosis presenting as pathologically excessive focal or generalized sweating. The stigmatizing nature of hyperhidrosis may cause patients to feel embarrassment and apprehension about their symptoms and experience a significant decrease in well-being. Severe cases of hyperhidrosis can also increase the risk of developing psychiatric and somatic comorbidities. Conventional non-surgical treatments of hyperhidrosis include aluminum salts, iontophoresis, botulinum toxin injections, and oral glycopyrronium. In recent years, new topical anticholinergic medications and devices have emerged that may improve the patients' symptoms and even prevent the development of comorbidities. The treatment of hyperhidrosis can be a complex matter and may require the combination of several therapies. The purpose of this paper was to firstly review the literature on existing non-surgical treatment options for hyperhidrosis, and secondly provide a stepwise approach to investigating and treating patients with hyperhidrosis.

Utilities of Botulinum Toxins in Dermatology and Cosmetology

Botulinum toxin (BoNT) is a neurotoxin produced by the Clostridium botulinum bacterium with a well-known efficacy and safety profile in the focal idiopathic hyperhidrosis treatment. BoNT comprises seven different neurotoxins; however, only toxins A and B are clinically employed. BoNT is lately practiced in off-label therapies for a variety of skin diseases. Scar prevention, hyperhidrosis, rhytides, eccrine nevus, alopecia, psoriasis, Darier disease, bullous skin disease, pompholyx and Raynaud's phenomenon are some of the novel indications for BoNT in cosmetic and notably non-cosmetic aspects of dermatology. To employ BoNT correctly in clinical practice, we must have a thorough understanding of the functional anatomy of the mimetic muscles. An intensive literature search was conducted to update all dermatology-oriented experiments and clinical trials on the described element of BoNT for this general overview of BoNT use in dermatology. This review aims to analyse the role of BoNT in dermatology and cosmetology.

Botulinum Toxin Versus Placebo: A Meta-Analysis of Treatment and Quality-of-life Outcomes for Hyperhidrosis

AIMS

This study aims at assessing the treatment effect, disease severity and quality-of-life outcomes of botulinum toxin (BTX) injections for focal hyperhidrosis.

METHODS

We included randomized controlled trials of BTX injections compared with placebo for patients with primary or secondary focal hyperhidrosis. PubMed, Embase and the Cochrane Library were searched to August 2020. Gravimetric sweat rate reduction, disease severity measured by Hyperhidrosis Disease Severity Scale and quality-of-life assessment measured by Dermatology Life Quality Index were the outcomes of interest. Cochrane risk-of-bias tools were employed for quality assessment of given randomized controlled trials.

RESULTS

Eight studies met our inclusion criteria (n=937). Overall, risk bias was mixed and mostly moderate. BTX injections showed reduced risk in comparison with placebo for the gravimetric quantitative sweat reduction of > 50 % from baseline (risk difference: 0.63, 95% CI 0.51 to 0.74). Additionally, improvements were seen for disease severity and quality-of-life assessments evaluated by Hyperhidrosis Disease Severity Score reduction of ≥ 2 points (risk difference: 0.56, 95% CI 0.42 to 0.69) and mean change in Dermatology Life Quality Index (mean difference: - 5.55, 95% CI - 7.11 to - 3.98). The acquired data were insufficient to assess for long-term outcomes and limited to an eight-week follow-up period.

CONCLUSIONS

In focal axillary hyperhidrosis, BTX significantly reduces sweat production and yields superior outcomes in assessments of disease severity and quality-of-life. However, the quality-of-evidence is overall moderate and included studies account for short-term trial periods only. Further studies assessing BTX in comparison with first-line treatments for hyperhidrosis are warranted.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Current treatment options for craniofacial hyperhidrosis

Hyperhidrosis (HH) is characterized by sweating exceeding the amount necessary to meet the thermal regulation and physiological needs of the body. Approximately 9.41% of individuals with HH have craniofacial hyperhidrosis (FH). The present study aims to review the most current data in the literature regarding craniofacial hyperhidrosis, including pathophysiology, diagnosis and clinical presentation, treatment options (clinical and surgical), and outcomes. VATS (videothoracoscopy sympathectomy) is considered the gold standard for definitive treatment of axillary or palmar hyperhidrosis. Recently, several studies have shown the usefulness of clinical treatment with oxybutynin hydrochloride, leading to clinical improvement of HH in more than 70% of users. Both clinical and surgical treatment of craniofacial hyperhidrosis have good results. However, surgical treatment of FH is associated with more complications. Clinical treatment with oxybutynin hydrochloride yields good results and can be the first therapeutic option. When the patient is not satisfied with this treatment and has good clinical conditions, surgical treatment can be used safely.