Is there a therapeutic effect of botulinum toxin on scalp alopecia? Physiopathology and reported cases: A systematic review of the literature

Intradermal Injection in Balding Region Versus Intramuscular Injection in Surrounding Muscles: A Split-Scalp, Randomized Trial on BoNT for Androgenetic Alopecia

INTRODUCTION

Recent advancements in androgenetic alopecia (AGA) treatment have highlighted the efficacy of botulinum toxin (BoNT). However, inconsistencies in injection sites and depths warrant attention. It remains unclear which injection strategy is most beneficial for patients.

METHODS

This split-scalp randomized controlled trial divided each enrolled participant's scalp along the midline: one side was randomized to receive intramuscular BoNT injections in the surrounding muscles, while the other side received intradermal BoNT injections directly into the balding areas. This study evaluated the impact of treatment on hair density and diameter through trichoscopic examinations conducted at baseline and 12 weeks post treatment. Additionally, assessments of pain and overall safety were integrated into the study protocol.

RESULTS

Twenty-nine patients completed the study, with significant improvements in hair density observed in the intramuscular injection group compared to the intradermal group (p < 0.001). Both groups exhibited increases in hair diameter, but no significant difference was found between the two methods (p = 0.433). Pain evaluation revealed that intradermal injections in balding areas were more painful than intramuscular injections (p = 0.036), with no severe adverse reactions reported except for a single case of alopecia areata following injection.

CONCLUSION

Our research revealed that both BoNT injection strategies enhanced hair diameter 12 weeks post-treatment, with intramuscular injections significantly improving hair density more effectively. Despite the promising outcomes, the variability in patient responses underscores the necessity for personalized approaches and further research to refine injection protocols for optimized efficacy and safety.

TRIAL REGISTRATION NUMBER

ChiCTR2400080190.

Systematic review of mesotherapy: a novel avenue for the treatment of hair loss

Mesotherapy is a technique by which lower doses of therapeutic agents and bioactive substances are administered by intradermal injections to the skin. Through intradermal injections, mesotherapy can increase the residence time of therapeutic agents in the affected area, thus allowing for the use of lower doses and longer intervals between sessions which may in turn improve the treatment outcome and patient compliance. This systematic review aims to summarize the current literature that evaluates the efficacy of this technique for the treatment of hair loss and provides an overview of the results observed. Of the 416 records identified, 27 articles met the inclusion criteria. To date, mesotherapy using 6 classes of agents and their combinations have been studied; this includes dutasteride, minoxidil, growth factors or autologous suspension, botulinum toxin A, stem cells, and mesh solutions/multivitamins. While several studies report statistically significant improvements in hair growth after treatment, there is currently a lack of standardized regimens. The emergence of adverse effects after mesotherapy has been reported. Further large-scale and controlled clinical trials are warranted to evaluate the utility of mesotherapy for hair loss disorders.

Treatment of Androgenetic Alopecia: Current Guidance and Unmet Needs

Androgenetic alopecia (AGA) is the most common cause of hair loss in men and women. Traditionally, topical minoxidil and oral finasteride have been the standard of care yielding mixed results. New treatments such as Low-Level Laser Therapy (LLLT), microneedling, platelet-rich plasma (PRP), and others have been extensively studied in the literature, and the purpose of this review is to provide a comprehensive discussion of the latest treatment methods and their efficacy in treating AGA. Novel therapies such as oral minoxidil, topical finasteride, topical spironolactone, botulinum toxin, and stem cell therapy offer interesting alternatives to standard of care therapies for patients. In this review, we present data from recent studies on the clinical efficacy of these treatments. Furthermore, as new treatments have emerged, clinicians have tested combination therapies to assess whether there may be a synergistic relationship between multiple modalities. While there has been a great increase in the treatments available for AGA, the quality of evidence varies greatly and there is still a great need for randomized double blinded clinical trials to adequately assess the clinical efficacy of some treatments. While PRP and LLLT have demonstrated encouraging results, standardized treatment protocols are needed to adequately inform clinicians on how to use such therapies. Given the abundance of new therapeutic options, clinicians and patients must weigh the benefits and risks of each treatment option for AGA.

Alopecia After Cosmetic Injection Procedures: A Review

BACKGROUND

Cosmetic procedures for antiaging carry inherent risks of adverse events. One that has not yet been well characterized is transitory or permanent alopecia. This is attributable to numerous mechanisms including pressure, ischemia, inflammation, and necrosis. Cases of postcosmetic procedure alopecia have been reported after mesotherapy as well as hyaluronic acid filler, deoxycholic acid, and botulinum toxin injections.

OBJECTIVE

This review serves to describe the currently known causes of postcosmetic procedure alopecia and the mechanisms by which alopecia is attained. Furthermore, this review highlights the risk of unregulated mesotherapy injections for cosmetic enhancement and to bring attention to the increasing number reports of alopecia after these procedures.

METHODS

A systematic review of the literature from 2000 to 2022 was conducted looking for keywords such as "alopecia," "cosmetic procedures," "mesotherapy," and "hyaluronic acid" in Google Scholar and PubMed.

RESULTS

Ten articles met the criteria set forth in the authors' literature review. Many of the procedures resulted in partial or complete resolution of alopecia.

CONCLUSION

Alopecia after cosmetic injection procedures is an underreported adverse effect. More research is needed to further characterize the risk of alopecia after mesotherapy and other injection procedures.

Off-Label Use of Botulinum Toxin in Dermatology—Current State of the Art

Botulinum toxin (BoNT) is a neurotoxin produced by the Clostridium botulinum bacteria. Among seven different isoforms, only BoNT-A and BoNT-B are commercially used. Currently, botulinum toxin has been indicated by the U.S. Food and Drug Administration in several disorders, among others: chronic migraine, hyperhidrosis, urinary incontinence from detrusor overactivity, or cosmetics. However, there are numerous promising reports based on off-label BTX usage, indicating its potential effectiveness in other diseases, which remains unknown to many. Among them, dermatological conditions, such as rosacea, annal fissure, Raynaud phenomenon, hypertrophic scars and keloids, and also hidradenitis suppurativa, are currently being investigated. This article aims to provide a comprehensive update on the off-label use of botulinum toxin in dermatology, based on an analysis and summary of the published literature.

Complementary Strategies to Promote Hair Regrowth in Post-COVID-19 Telogen Effluvium

Post-COVID-19 telogen effluvium has been largely reported as a sequela in the post-acute phase of COVID-19, causing major emotional distress among the affected patients. The affected individuals are further exposed to a vast amount of misinformation from the internet and social media and it is important for physicians to be familiar with the phenomenon and provide appropriate counselling to their patients regarding this condition. This article aims to review the evidence-based complementary strategies that can help enhance hair regrowth after post-COVID-19 hair loss, from psychological support and patient education to the importance of optimal nutrition and potential indications and benefits of oral nutritional supplementation, as well as the role of both topical and injectable hair growth stimulators.

Current use of botulinum neurotoxin in esthetic practice-Clinical guide and review

BACKGROUND

Botulinum neurotoxin is one of the most versatile and widely used medical products in the world.

AIMS

The review's focus is the plastic and dermatologic uses of botulinum neurotoxin currently supported by published data.

METHODS

Relevant clinical articles regarding botulinum neurotoxin use in plastic surgery, dermatology, and general esthetic literature were searched and reviewed.

RESULTS

The search yielded 258 studies. Two hundred articles were excluded following title and abstract review. Twenty-one studies were excluded following full-text screening. A total of 37 studies remained and were discussed in this review.

CONCLUSIONS

Botulinum neurotoxin is widely used for numerous off-label indications from head to toe. Some uses are well documented, and their safety has been demonstrated in controlled trials, yet most remain poorly researched.

Therapeutic Use of Botulinum Neurotoxins in Dermatology: Systematic Review

Botulinum toxin is a superfamily of neurotoxins produced by the bacterium Clostridium Botulinum with well-established efficacy and safety profile in focal idiopathic hyperhidrosis. Recently, botulinum toxins have also been used in many other skin diseases, in off label regimen. The objective of this manuscript is to review and analyze the main therapeutic applications of botulinum toxins in skin diseases. A systematic review of the published data was conducted, following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Botulinum toxins present several label and off-label indications of interest for dermatologists. The best-reported evidence concerns focal idiopathic hyperhidrosis, Raynaud phenomenon, suppurative hidradenitis, Hailey–Hailey disease, epidermolysis bullosa simplex Weber–Cockayne type, Darier’s disease, pachyonychia congenita, aquagenic keratoderma, alopecia, psoriasis, notalgia paresthetica, facial erythema and flushing, and oily skin. Further clinical trials are still needed to better understand the real efficacy and safety of these applications and to standardize injection and doses protocols for off label applications.