Injectable and topical neurotoxins in dermatology: Basic science, anatomy, and therapeutic agents

Botulinum Toxin A for Hair Loss Treatment: A Systematic Review of Efficacy, Safety, and Future Directions

Background

Hair loss is a common condition with significant impact globally, yet its treatment efficacy and safety remain debated. Botulinum toxin A (BoNT-A) has emerged as a potential therapeutic option, but a comprehensive review on this topic is lacking.

Objective

This review critically evaluates the current evidence on BoNT-A for hair loss treatment, highlighting the gaps in previous reviews and providing a comprehensive analysis of its efficacy, safety, and future prospects.

Methods

A systematic search of electronic databases identified relevant studies published up to September 2022.

Results

Prior reviews primarily focused on androgenetic alopecia and lacked the evaluation of other alopecia types and underlying mechanisms. Our review addresses this gap, incorporating a broader spectrum of hair loss conditions. Mechanisms of BoNT-A in hair growth modulation, potential side effects, and future research directions are discussed.

Conclusion

This review adds to the existing body of knowledge by providing a comprehensive evaluation of BoNT-A in hair loss treatment. The findings will serve as a foundation for further research and guide clinicians in making informed decisions, ultimately improving the outcomes and quality of life for individuals suffering from hair loss.

Assessment and Treatment Strategies for the Aesthetic Improvement of the Lower Face and Neck

Background

Interest in aesthetic rejuvenation of the lower face and neck is growing, but published expert guidance is limited.

Objective

Review aesthetic concerns of the lower face and neck and provide expert guidance on evaluation and treatment.

Methods

Twelve international experts participated in an advisory board on lower face and neck aesthetic treatment. They completed a premeeting survey and met twice, reviewing responses and discussing patient evaluation and treatment strategies. They developed decision tree algorithms on patient assessment and treatment planning and sequencing, using clinical cases as a reference.

Results

Treatment concerns include neck and lower face skin laxity, structural bone deficiency, insufficient or excess volume, submental fat, jowls, platysma bands, and masseter muscle prominence. Advisors agreed that the lower face and neck may be the most challenging areas to assess and treat; treatment goals include lower facial contour and overall facial harmony/balance. Advisors recommended first ruling out a surgical approach, then determining whether midface treatment is needed to support the lower face, and lastly evaluating the lower face for significant submental fat, excess or insufficient volume, and structural bone deficiency. To treat the lower face and neck, an anatomical layer approach, moving from deep to superficial layers, beginning with structural support, was recommended. Assessment and treatment decision trees were based on this approach.

Conclusion

The lower face and neck are important but underrecognized areas of aesthetic concern. This article provides expert guidance and a suggested algorithm for assessment and treatment aimed at achieving satisfying and harmonious facial aesthetic results.

The Air Toxin Technique: Introduction and Analysis of Effect using a Photo Imaging System

BACKGROUND

As an alternative to other approaches to facial rejuvenation, the air toxin technique (dermal injection of air with micro-doses of botulinum toxin) is a promising method. We aimed to describe this novel technique and assess the overall safety and efficacy of the air toxin technique in facial rejuvenation.

MATERIALS AND METHODS

A retrospective chart review was performed on cases treated with the air toxin technique. A total of 47 Korean patients underwent a single treatment session. Treatment efficacy was assessed objectively with serial VISIA® (Canfield Scientific, NJ, USA) skin analysis data and subjectively based on the patients' assessment scores at week 12.

RESULTS

A significant improvement in Wrinkle (p < 0.001), UV spot (p < 0.001), and Porphyrin (p = 0.005) were objectively seen at 12-weeks follow-up. Patients noted improvement in the categories Wrinkle (p < 0.01), Redness (p = 0.029), Texture (p < 0.001), Dilated pore (p < 0.001), and Lifting (p < 0.001) at week 12 compared to baseline. No major adverse event was reported.

CONCLUSIONS

Our data show that the Air toxin technique is efficacious in facial rejuvenation as shown by improved skin analysis parameters and patient assessment scores. Notably, there was some discrepancy between the objective and subjective parameters of improvement.

Forehead Movement Discrepancies After Botulinum Toxin Injections: A Review of Etiology, Correction, and Prevention

BACKGROUND

Forehead rhytides are a popular target for botulinum toxin injections, but neuromodulation of the frontalis can be fraught with complications because of its anatomic complexity and integral role in brow position and expressivity.

OBJECTIVE

This article explores common forehead movement discrepancies that can occur after neuromodulation of the frontalis, as well as how to correct and prevent them.

METHODS

A review of the literature was conducted and combined with clinical experience to examine underlying forehead anatomy, etiology and correction of forehead movement discrepancies, and important factors to consider before injecting the frontalis with botulinum toxin.

RESULTS AND CONCLUSION

Variable anatomy from person to person necessitates an individualized treatment approach to achieve the best cosmetic results and prevent the occurrence of forehead movement discrepancies.

Skin Quality - A Holistic 360° View: Consensus Results

Introduction

Skin quality is an important component of human attractiveness. To date, there are no standardized criteria for good skin quality. To establish a consensus for good skin quality parameters and measurement and treatment options, a virtual skin quality advisory board consisting of a global panel of highly experienced aesthetic dermatologists/aesthetic physicians was convened.

Methods

A total of 10 dermatologists/aesthetic physicians served on the advisory board. A modified version of the Delphi method was used to arrive at consensus. Members accessed an online platform to review statements on skin quality criteria from their peers, including treatment and measurement options, and voted to indicate whether they agreed or disagreed. Statements that did not have agreement were modified and the members voted again. Consensus was defined as: strong consensus = greater than 95% agreement; consensus = 75% to 95% agreement; majority consent = 50% to 75% agreement; no consensus = less than 50% agreement.

Results

There was strong consensus that good skin quality is defined as healthy, youthful in appearance (appearing younger than a person's chronological age), undamaged skin and that skin quality can be described across all ethnicities by four emergent perceptual categories (EPCs): skin tone evenness, skin surface evenness, skin firmness, and skin glow. The EPCs can be affected by multiple tissue layers (ie, skin surface quality can stem from and be impacted by deep structures or tissues). This means that topical approaches may not be sufficient. Instead, improving skin quality EPCs can require a multilayer treatment strategy.

Conclusion

This global advisory board established strong consensus that skin quality can be described by four EPCs, which can help clinicians determine the appropriate treatment option(s) and the tissue or skin layer(s) to address. Skin quality is important to human health and wellbeing and patients' perception for the need for aesthetic treatment.

Management of Urgency and Mixed Urinary Incontinence

Urinary incontinence (UI) is a prevalent disorder that significantly affects quality of life. This article reviews management of urgency and mixed UI by breaking the management algorithm down into observation, lifestyle and behavioral changes, pharmacologic therapy, and procedural management. Stress UI is best managed with mid-urethral slings and is covered in other chapters. Behavioral and pharmacologic management are equally efficacious for urgency UI, but procedural therapy is superior. Mixed UI is conventionally treated by first managing whichever UI subtype is most bothersome. The management of overflow UI is directed at its underlying etiology: detrusor underactivity or bladder outlet obstruction.

Botulinum Toxin A: A Review of Potential Uses in Treatment of Female Urogenital and Pelvic Floor Disorders

Background: Botulinum toxin is an injectable neuromodulator that inhibits transmission between peripheral nerve endings and muscle fibers, resulting in muscle paralysis. Botulinum toxin type A is the most common form of botulinum toxin used in clinical practice.

Methods: In this review, we examine the mechanism of action, formulations, common clinical use in the genital-urinary tract, and potential clinical use in pelvic floor disorders of botulinum toxin type A.

Results: Several aspects of botulinum toxin A make it a favorable therapeutic tool, including its accessibility, its longevity, and its impermanence and reversibility of resultant chemodenervation in a relatively short and safe manner. Although botulinum toxin A has well-established efficacy in treating refractory overactive bladder and neurogenic detrusor overactivity, its use in pelvic floor disorders is still in its infancy.

Conclusion: The efficacy of botulinum toxin A for treating pelvic pain, voiding dysfunction, muscle pain and dysfunction, and certain colorectal-related pain issues shows promise but requires additional rigorous evaluation.

A Nurse-Led Clinic Model for the Treatment of Cervical Dystonia Using Botulinum Toxin

Dystonia is a neurological movement disorder characterised by sustained or intermittent muscle contractions, producing abnormal and often repetitive movements, abnormal posture or both. It is often accompanied by chronic pain, depression and anxiety. The treatment of dystonia is primarily symptomatic, designed to improve posture and function and to relieve associated pain. This can include oral medications, botulinum toxin (BoNT) injection, and deep brain stimulation (DBS). This article will focus on BoNT treatment, which is just one facet in the treatment of cervical dystonia. The involvement of clinical nurse specialists and the use of a nurse-led clinic can increase efficiency and effectiveness (namely, increased clinic efficiency and capacity, reduced appointment waiting times, and improved continuity of care for the patients), as well as patient access, education, psychosocial support, monitoring and, ultimately, empowerment. This article will discuss the key elements, considerations and benefits of setting up a nurse-led clinic for patients with dystonia.

Botulinum toxin: Pharmacology and injectable administration for the treatment of primary hyperhidrosis

Hyperhidrosis is a dermatological condition defined by excessive sweating beyond thermoregulatory needs with significant effects on patients' quality of life. Hyperhidrosis is categorized as primary or secondary: primary hyperhidrosis is mostly focal and idiopathic, whereas secondary hyperhidrosis is commonly generalized and caused by an underlying medical condition or use of medications. Various surgical and nonsurgical therapies exist for primary hyperhidrosis. Although botulinum toxin is one of the deadliest toxins known, when used in small doses, it is one of the most effective therapies for primary hyperhidrosis. Botulinum toxin injections are widely used as a second-line primary hyperhidrosis treatment option once topical treatment strategies have failed. This article provides an overview of the commercially available botulinum toxin formulations and their applications in the treatment of primary hyperhidrosis.

Botulinum toxin therapy of bipolar depression: A case series

We and others have recently found that botulinum toxin injected into the brow muscles has significant antidepressant properties as compared to placebo in randomized controlled trials in patients with major depressive disorder. However, data for the treatment of bipolar depression with botulinum toxin is lacking. We report here six patients with bipolar disorder experiencing moderate to severe depressive episodes who were treated on a compassionate basis with botulinum toxin given their persistent depressive symptoms and adverse side effects from medications. Four of six patients with bipolar depression experienced a remission following treatment with botulinum toxin, and the other two patients experienced a reduction of depressive symptoms. When the effect of botulinum toxin on the frown muscles began to wear off, depressive symptoms returned and retreatment with botulinum toxin provided successful relief of depressive symptoms again.