Efficacy of hydroquinone-free skin-lightening cream for photoaging

Cosmetovigilance for infrequent allergens in Spain using a national online registry: The example of allergic contact dermatitis caused by phenylethyl resorcinol

BACKGROUND

Monitoring of adverse events induced by cosmetics performed by health authorities, known as cosmetovigilance, has been relied on the collection of case notifications.

OBJECTIVES

We aimed to show how a contact dermatitis registry can contribute to the cosmetovigilance of emerging allergens. We used the example of phenylethyl resorcinol, an infrequent allergen with only 6 previous cases reported in Europe and Japan since 2013.

METHODS

A systematic search in the Spanish Registry of Contact Dermatitis and Cutaneous Allergy (REIDAC) database was performed to identify patients with positive patch test to phenylethyl resorcinol or cosmetics that contains it between June 2018 and January 2023. We collected the main clinical features of these patients and compared them with those of patients recorded in the registry with similar epidemiological features.

RESULTS

Thirteen patients with positive patch test to phenylethyl resorcinol were identified. All the patients were women with a mean age of 42 years (range 32-59) and their lesions were mainly in the face.

CONCLUSION

Assessing the importance of infrequent allergens based solely on a case series is difficult. Multicentre registries facilitate the collection of cases and provide appropriate background information for new allergens.

Skin dark spot mapping and evaluation of brightening product efficacy using Line-field Confocal Optical Coherence Tomography (LC-OCT)

BACKGROUND

Facial dark spots remain a significant challenge for the cosmetic industry, in terms of providing effective treatment. Using Line-field Confocal Optical Coherence Tomography (LC-OCT), we investigated the internal structural features of photo-aging spot areas and evaluated the efficacy of a skin-brightening cosmetic product.

MATERIALS AND METHODS

Twenty-six Asian female volunteers, aged between 29 and 65 years, applied a cosmetic product on their entire face twice a day for 2 months. LC-OCT was used to evaluate the dermal-epidermal junction (DEJ) undulation and the volume density of melanin in the epidermis at D0 and D56. Skin brightening and redness were also assessed by photography (SkinCam).

RESULTS

Using LC-OCT technology, various microscopic dark spot morphologies, spanning from minimally deformed DEJ to complex DEJ patterns, were identified. Dark spots characterized by slight deformities in the DEJ were predominantly observed in the youngest age group, while older volunteers displayed a wavier pattern. Furthermore, a total of 44 spots were monitored to evaluate the brightening product efficacy. A statistically significant reduction in melanin volumetric density of 7.3% in the spots and 12.3% in their surrounding area was observed after 56 days of product application. In line with these results, an analysis of color parameters using SkinCam reveals a significant increase in brightening and decrease in redness in both pigmented spots and the surrounding skin following application.

CONCLUSIONS

LC-OCT proves to be a valuable tool for in-depth dark spots characterization and assessment of skin brightening products, enabling various applications in the field of dermatological sciences.

Blue light and skin: what is the intriguing link?

Blue light has garnered attention because of its ability to penetrate more deeply into the skin layers, and induce cellular dysfunction and DNA damage. Photoageing, hyperpigmentation and melasma are some of the cutaneous changes that develop on exposure to blue light. To date, the therapeutic roles of blue light have been evaluated in dermatological conditions like psoriasis, eczema, acne vulgaris, actinic keratosis and cutaneous malignancies, among others. In this review, we have attempted to present an evidence-based compilation of the effects of blue light on the skin.

TFOS Lifestyle: Impact of cosmetics on the ocular surface

In this report the use of eye cosmetic products and procedures and how this represents a lifestyle challenge that may exacerbate or promote the development of ocular surface and adnexal disease is discussed. Multiple aspects of eye cosmetics are addressed, including their history and market value, psychological and social impacts, possible problems associated with cosmetic ingredients, products, and procedures, and regulations for eye cosmetic use. In addition, a systematic review that critically appraises randomized controlled trial evidence concerning the ocular effects of eyelash growth products is included. The findings of this systematic review highlight the evidence gaps and indicate future directions for research to focus on ocular surface outcomes associated with eyelash growth products.

Skin Pigmentation Types, Causes and Treatment-A Review

Human skin pigmentation and melanin synthesis are incredibly variable, and are impacted by genetics, UV exposure, and some drugs. Patients' physical appearance, psychological health, and social functioning are all impacted by a sizable number of skin conditions that cause pigmentary abnormalities. Hyperpigmentation, where pigment appears to overflow, and hypopigmentation, where pigment is reduced, are the two major classifications of skin pigmentation. Albinism, melasma, vitiligo, Addison's disease, and post-inflammatory hyperpigmentation, which can be brought on by eczema, acne vulgaris, and drug interactions, are the most common skin pigmentation disorders in clinical practice. Anti-inflammatory medications, antioxidants, and medications that inhibit tyrosinase, which prevents the production of melanin, are all possible treatments for pigmentation problems. Skin pigmentation can be treated orally and topically with medications, herbal remedies, and cosmetic products, but a doctor should always be consulted before beginning any new medicine or treatment plan. This review article explores the numerous types of pigmentation problems, their causes, and treatments, as well as the 25 plants, 4 marine species, and 17 topical and oral medications now on the market that have been clinically tested to treat skin diseases.

Pigmentation effects of blue light irradiation on skin and how to protect against them

Background

Visible light, in particular blue light, has been identified as an additional contributor to cutaneous photoageing. However, clinical studies demonstrating the clear effect of blue light on photoageing are still scarce, and so far, most studies have focused on broad‐spectrum visible light. Although there is evidence for increased skin pigmentation, the underlying mechanisms of photoageing in vivo are still unclear. Furthermore, there is still a need for active ingredients to significantly protect against blue light‐induced hyperpigmentation in vivo.

Our study had two aims: to detect visible changes in skin pigmentation following repeated irradiation of the skin with LED‐based blue light and to reduce pigmentation using suitable active ingredients.

Method

We conducted a randomized, double‐blind and placebo‐controlled clinical study on 33 female volunteers with skin phototypes III and IV. We used a repetitive blue light (4 × 60 J cm⁻², 450 nm) irradiation protocol on the volunteers’ inner forearms. Using hyperspectral imaging, we assessed chromophore status. In addition, we took chromameter measurements and photographs to assess visible hyperpigmentation.

Results

We measured significant changes in chromophore status (P < 0.001 vs baseline), that is of melanin, haemoglobin and oxygen saturation, immediately after blue light irradiation. In addition, we found visible skin colour changes which were expressed by a significant decrease in ITA° values (delta ITA° = −16.89, P < 0.001 vs baseline for the placebo group) and an increase in a* (delta a* = +3.37, P < 0.001 vs baseline for the placebo group) 24 h post‐irradiation. Hyperpigmentation and skin reddening were mitigated by both a formulation containing 3% of a microalgal product and a formulation containing 3% niacinamide.

Conclusion

Our study sets out an efficient and robust protocol for investigating both blue light‐induced cutaneous alterations, such as changes in skin chromophores, and signs of photoageing, such as hyperpigmentation. Moreover, we have shown evidence that both an extract of the microalga Scenedesmus rubescens and niacinamide (vitamin B3) have the potential to protect against blue light‐induced hyperpigmentation.

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.

Characterization and topical delivery of phenylethyl resorcinol

OBJECTIVE

Phenylethyl resorcinol (PR) has been used widely in the personal care industry as a novel skin lightening ingredient. Surprisingly, there is only limited information describing the physicochemical properties of this active. Therefore, the primary objective of this study was to perform a comprehensive characterization of PR. A secondary objective was to investigate the delivery of this molecule to mammalian skin.

METHODS

Phenylethyl resorcinol was characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and nuclear magnetic resonance (NMR). A new high-performance liquid chromatographic (HPLC) method for analysis of PR was developed and validated. The log P (octanol water partition coefficient), value, solubility and short-term stability of PR in a series of vehicles were also determined using HPLC. The evaporation of the selected vehicles was examined using dynamic vapour sorption (DVS). The permeation profiles of PR were investigated under finite dose conditions in porcine and human skin.

RESULTS

The melting point of PR was determined to be 79.13 °C and the measured log P (octanol water partition coefficient) at 21 °C was 3.35 ± 0.03. The linearity of the HPLC analytical method was confirmed with an r² value of 0.99. Accuracy of the method was evaluated by average recovery rates at three tested concentrations, and the values ranged from 99 to 106%. The limit of detection (LOD) and limit of quantification (LOQ) were 0.19 and 0.57 μg mL^-1 , respectively. The solubility of PR in PG, DMI, glycerol was within the range of 367 to 877 mg mL^-1 . The stability of PR in tested solvents was also confirmed by the 72 h stability studies. From the DVS studies, 70-125% of applied formulations were recovered at 24 h. The permeation through porcine skin at 24 h ranged from 4 to 13 μg cm^-2 , while the corresponding amounts of PR delivered through human skin were 2 to 10 μg cm^-2 .

CONCLUSION

The physicochemical properties of PR confirm it is suitable for dermal delivery. In this study, propylene glycol was the most promising vehicle for PR delivery to human skin. Future work will expand the range of vehicles studied and explore the percutaneous absorption from more complex formulations.

Efficacy of D-pigment dermocosmetic lightening product for solar lentigo lesions of the hand: A randomized controlled trial

Solar lentigo, benign lesions which mostly appear on chronically, sun-exposed surfaces, are associated with ageing. Patients are increasingly requesting a more uniform skin texture, especially for hands. Treatment options include dermoabrasion, intense pulsed light, cryotherapy, peelings, and laser therapy. Topical compounds can be employed, in alternative or associated with dermatologic procedures. The current study was designed to evaluate solar lentigo hyperpigmentation, skin architecture and clinician and patient assessments comparing a dermocosmetic lightening product (active) with a moisturizing product (control) according to clinical, digital and subjective analyses in 72 lesions over 12-month follow up period. Statistically significant differences were observed between the lesions treated with the active compared to the control in terms of papillary brightness (p = 0.03) and contrast (p = 0.03), and in the limitation of dermal-epidermal junction destructuring (p = 0.03) according to dermal-epidermal junction destructuring score at Reflectance Confocal Microscopy. Luminance (p = 0.04) and redness (p = 0.03) were improved at color analysis, and physician and patient evaluations favored the active in efficacy and patient satisfaction investigations. The dermocosmetic lightening product utilized in the current study proved to be more effective, according to clinical, digital and subjective analyses in reducing lesion hyperpigmentation, stabilizing the lesion skin architecture and increasing patient satisfaction compared to the control in a cohort of 36 subjects, over a 12-month period. Beside demonstrating the efficacy of this topical lightening product, we propose a “destructuring score”, which improves the robustness of solar lentigo’s evaluation, and can be used in future studies to standardize the quantitative comparisons of different treatment options.

Phytochemical screening and antityrosinase activity of carvacrol, thymoquinone, and four essential oils of Lebanese plants

OBJECTIVE

In our study, we aim to explore the ability of four essential oils (EO) of Lebanese plants to inhibit the tyrosinase activity and to correlate their efficiency level to their phytochemical compositions.

METHODS

The EO have been extracted by hydrodistillation using a Clevenger apparatus and have been studied by GC-MS analysis. Active compounds of Origanum species were identified and antityrosinase activities of EO and active molecules (carvacrol and thymoquinone) have been tested in tubo.

RESULTS

Antityrosinase activities were obtained as follows: EO of Origanum syriacum (80.41% ± 2.00%), EO of Origanum ehrenbergii (45.33% ± 2.20%), EO of Salvia fruticosa (14.62% ± 2.30%), EO of Calamintha origanifolia (16.51% ± 5.80%), Carvacrol (56.55% ± 3.10%), and Thymoquinone (19.49% ± 1.50%).

CONCLUSION

Origanum essential oils resulted in the highest antityrosinase activity due to their high content in carvacrol. However, when present together with carvacrol, thymoquinone decreases the efficiency of carvacrol, which is the case of O. ehrenbergii essential oil. Thus, for improved antityrosinase activity, O. syriacum and O. ehrenbergii should be harvested during flowering stage where carvacrol is present at its highest dosage and thymoquinone at its lowest.

Consensus Recommendations for Combined Aesthetic Interventions Using Botulinum Toxin, Fillers, and Microfocused Ultrasound in the Neck, Décolletage, Hands, and Other Areas of the Body

BACKGROUND

The popularity of aesthetic procedures in the face has led to greater disparity between treated areas and those that still show evidence of true age. Although many areas of the body often require multiple treatment procedures for optimal rejuvenation, combination therapy for specific areas is not yet well defined.

OBJECTIVE

To develop recommendations for the optimal combination and ideal sequence of botulinum toxin (BoNT), hyaluronic acid, calcium hydroxylapatite (CaHA), and microfocused ultrasound with visualization in nonfacial areas across all skin phototypes.

METHODS

Fifteen specialists convened under the guidance of a certified moderator. Consensus was defined as approval from 75% to 94% of all participants, whereas agreement of ≥95% denoted a strong consensus.

RESULTS

Recommendations have been provided for the neck, décolletage, and hands and include the timing and sequence of specific procedures when used concurrently or over several treatment sessions. Position statements are offered in lieu of consensus for the upper arms, abdomen, buttocks, and knees.

CONCLUSION

Nonfacial rejuvenation often requires multiple procedures for optimal results in individuals with significant age-related changes. Further clinical studies are recommended to raise awareness of non-facial indications and provide clinicians with the best evidence for best treatment practices.

Efficacy and Safety of Topical Pidobenzone 4% as Adjuvant Treatment for Solar Lentigines: Result of a Randomized, Controlled, Clinical Trial

BACKGROUND/OBJECTIVE

This study aims at the evaluation of the efficacy and safety of a combination therapy based on pidobenzone 4% and fractional CO2 laser or cryotherapy in the treatment of solar lentigines and the prevention of eventual posttreatment hyperchromia.

METHODS

Efficacy was clinically evaluated by grading the pigmentation level with the Skin Tone Color Scale (STCS), and by grading patients' impression through a Visual Analog Scale (VAS).

RESULTS

Our study shows that the associated treatment was safe and that it improves the therapeutic results on solar lentigines and prevents postiatrogenic hyperpigmentation compared with physical therapy alone.

CONCLUSION

The combination of cryotherapy and pidobenzone 4% has been found to be the most useful treatment.

Characterizing facial skin ageing in humans: disentangling extrinsic from intrinsic biological phenomena

Facial skin ageing is caused by intrinsic and extrinsic mechanisms. Intrinsic ageing is highly related to chronological age. Age related skin changes can be measured using clinical and biophysical methods. The aim of this study was to evaluate whether and how clinical characteristics and biophysical parameters are associated with each other with and without adjustment for chronological age. Twenty-four female subjects of three age groups were enrolled. Clinical assessments (global facial skin ageing, wrinkling, and sagging), and biophysical measurements (roughness, colour, skin elasticity, and barrier function) were conducted at both upper cheeks. Pearson's correlations and linear regression models adjusted for age were calculated. Most of the measured parameters were correlated with chronological age (e.g., association with wrinkle score, r = 0.901) and with each other (e.g., residual skin deformation and wrinkle score, r = 0.606). After statistical adjustment for age, only few associations remained (e.g., mean roughness (R z ) and luminance (L (*)),  β = -0.507, R (2) = 0.377). Chronological age as surrogate marker for intrinsic ageing has the most important influence on most facial skin ageing signs. Changes in skin elasticity, wrinkling, sagging, and yellowness seem to be caused by additional extrinsic ageing.