Different Glabellar Contraction Patterns in Chinese and Efficacy of Botulinum Toxin Type A for Treating Glabellar Lines: A Pilot Study

Neuromodulators in Skin of Color: An International Review

BACKGROUND

As the racial/ethnic diversity of the US population grows, it is imperative for dermatologists to recognize the nuances in the aesthetic treatment of diverse populations.

OBJECTIVE

This comprehensive review explores the safety and efficacy of botulinum toxin A (BTX-A) in skin of color (SOC) populations and highlights variations in aging patterns, skin properties, and aesthetic concerns in SOC populations.

MATERIALS AND METHODS

A review of PubMed/MEDLINE databases from 2004 to 2024 was performed using combinations of the terms botulinum toxin, SOC, Fitzpatrick, race/ethnicity, and Asian, Latin American, Caribbean, Middle Eastern, African, and Pacific countries.

RESULTS

Twenty-three articles examining the use of BTX-A in SOC populations were identified. Twelve studies were from East Asia, 5 from the United States and/or Canada, 3 from South Asia/Southeast Asia, 2 from South America, and 1 from the Middle East. Available data suggest that BTX-A is efficacious and well tolerated in SOC populations.

CONCLUSION

Increased SOC representation in clinical trials may guide the development of tailored treatment approaches to optimize aesthetic outcomes for patients with SOC. A comprehensive knowledge of the variations in aging patterns, skin properties, and aesthetic concerns across SOC populations is essential for providing culturally sensitive cosmetic dermatologic care for diverse populations.

The Effect of Climate on the Dose Requirements of Botulinum Toxin A in Cosmetic Interventions

BACKGROUND

Botulinum toxin A to the glabella is a popular cosmetic intervention. Functional musculature differences may arise from chronic behavioral adjustment to high sun exposure levels, requiring greater doses. This could affect clinical practice globally. This study investigated the effect of climate on real-world doses.

METHODS

The authors conducted a comparative cohort study using data from a registry from a single provider practicing across two centers: the United Kingdom and Malta. They classified one center as low sun exposure (United Kingdom winter month treatment) and the other as high sun exposure (Malta summer months). Patients were followed up once every 3 weeks and received top-up doses until full clinical paralysis was achieved. To standardize the comparison, the study included only women aged 35 to 60 years undergoing glabellar botulinum toxin treatment by experienced clinicians following standard procedures from 2012 to 2019. Smokers, those not seeking maximal paralysis, those documented as not compliant with posttreatment advice, those with colds or fevers, and those with broken cold supply chains were excluded. Univariable and multivariable analyses were undertaken.

RESULTS

A total of 523 patients were included: 292 "high-sun" patients and 231 "low-sun" patients. Mean total doses were significantly higher in the high-sun group (29.2 units versus 27.3 units; P = 0.0031). When correcting for age in multivariable analysis, the low-sun group still had lower total dose requirements ( P = 0.00574).

CONCLUSION

Patients injected with glabellar botulinum toxin in high-sun climates may have significantly increased dose requirements to achieve maximal paralysis.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Cosmetic injectables in skin of color: A review of uses, safety, and effectiveness of neuromodulators and dermal fillers

BACKGROUND

Skin of color (SOC) individuals represent a growing market for cosmetic injectables and can have different aesthetic goals and responses to treatment.

OBJECTIVE

A review of the uses, safety, and effectiveness of injectable neuromodulators and dermal fillers in SOC individuals.

METHODS AND MATERIALS

A search of the PubMed/MEDLINE database was conducted from August 1960 to December 2020. Studies that were included either had a focus on SOC (>20% SOC study participants) or dedicated article content commenting on the safety and/or efficacy of injectables in SOC participants.

RESULTS

Of the 503 publications identified, a total of 88 articles were selected for this review. Differences in aging and cultural factors can influence aesthetic goals amongst SOC populations. Available data suggests that botulinum toxin (BTX) and dermal fillers are safe and effective in SOC populations, with the largest amount of data existing for Asian populations. There remains a paucity of research on Black and Latinx populations.

CONCLUSION

BTX and dermal fillers are generally effective and well tolerated in SOC populations, particularly Asian populations for which the greatest amount of data exists. More high quality, randomized controlled trials in Black and Latinx populations are warranted.

Cosmetic Considerations in Dark-Skinned Patients

For dermatologists, diversities of human races result in an opportunity to encounter patients with various skin types. Cosmetic procedures have gained more popularity and become more accessible over the past decades. Thus, the selection of appropriate treatment protocol for each patient becomes inevitable. This review will focus on basic knowledge and key points in performing safe cosmetic-related procedures in patients with dark-complexioned skin. In terms of structure and function of the skin, people of color have equal epidermal thickness, corneocyte size and melanocyte number. However, they have more stratum corneum compaction, melanosome dispersion and melanocyte activity than fair skin individuals. Data regarding drug penetration and cutaneous irritation showed conflicting results. Superficial chemical peels and microdermabrasion can be done safely in dark-skinned patients. Medium-depth peel should be used with extreme caution. While deep-depth peel should be avoided at all times due to pigmentary and textural complications. Prolonged treatment interval, use of priming agents and sun protection are recommended. Injectable materials including botulinum toxin and soft tissue augmentation by hyaluronic acid filler can be done harmlessly in dark-skinned patients. Lasers and energy-based devices should be done with caution. Higher melanin dispersion and melanocyte activity acts as competitive chromophore. Pigmentary or textural changes can occur after aggressive treatment protocol. High energy setting, pulse stacking, short wavelength lasers and short treatment interval should be avoided in dark-skinned patients.

An update on cosmetic procedures in people of color. Part 2: Neuromodulators, soft tissue augmentation, chemexfoliating agents, and laser hair reduction

Recent years have brought forth the undeniable practice gap in dermatology concerning knowledge and experience of cosmetic procedures in people of color (POC). A paucity in the literature regarding evidence-based recommendations for the management of POC undergoing cosmetic procedures and the rise of cosmetic procedures in dermatology serves as a call to action to provide education regarding differences in skin of color that may impact the cosmetic outcomes. To mitigate the current practice gap on the safety, use, and benefits of cosmetic procedures in POC, part 2 will discuss the authors' recommendations and clinical pearls, as well as evidence-based management for neuromodulators, soft tissue augmentation, chemexfoliating agents, and laser hair reduction in POC undergoing cosmetic procedures.

Ultrasonographic and Three-Dimensional Analyses at the Glabella and Radix of the Nose for Botulinum Neurotoxin Injection Procedures into the Procerus Muscle

Botulinum neurotoxin (BoNT) injections are widely used for facial rejuvenation procedures, and the procerus muscle is a major target in cases of glabellar transverse lines or rhytids. Although there have been many cadaveric studies of the procerus, its depth and thickness have not been investigated thoroughly. The aim of this study was to measure the depth and thickness of the procerus and identify the location of the intercanthal vein using ultrasonographic (US) imaging and the three-dimensional scanning method, which is needed to know to avoid side effects during BoNT injections. The morphology of the procerus was classified into two types based on the US images obtained at the glabella. The procerus was located deeper below the skin surface at the glabella than the sellion (3.8 ± 0.7 mm versus 2.7 ± 0.6 mm). The width of the procerus in US images increased from the sellion (10.9 ± 0.2 mm) to the glabella (14.5 ± 4.6 mm), whereas its thickness decreased (from 1.6 ± 0.6 mm to 1.1 ± 0.5 mm). The intercanthal vein was located 5.1 ± 4.0 mm superior to the sellion and 3.0 ± 0.6 mm below the skin’s surface. The present findings provide anatomical knowledge as well as the reference location information for use when injecting BoNT into the procerus.