Acne treatment challenges - Recommendations of Latin American expert consensus

BACKGROUND

Acne is a chronic inflammatory disorder of the pilosebaceous unit that is associated with a negative impact on quality of life, causing anxiety, depression, and poor self-esteem. The treatment of acne is not simple and presents some new challenges. This article addresses important issues faced by dermatologists on their daily, some of them specific for Latin America.

OBJECTIVE

To discuss daily practice recommendations when managing acne patients.

METHODS

A literature review was conducted by a group of eight experts with extensive experience in the field of acne. The results of the data review were presented at an initial kick-off meeting to align the consensus topics. Two e-surveys using the Delphi methodology and an interim group webinar meeting were held.

RESULTS

The expert panel reached a consensus on all proposed key statements, providing scientific support to help dermatologists and healthcare providers make acne management decisions on topics that can be challenging in the everyday practice of dermatology, such as the characteristics of Generation Z or the importance of the maintenance phase of adult acne treatment.

CONCLUSION

This article provides current recommendations for managing acne patients. The high level of agreement achieved based on the latest evidence supports the best acne therapeutic choices in both established topics and new important issues that have emerged in recent years, such as the impact of social media, Generation Z characteristics, and transgender male patient specifics.

Design and synthesis of 4-amino-2',4'-dihydroxyindanone derivatives as potent inhibitors of tyrosinase and melanin biosynthesis in human melanoma cells

Melanogenesis inhibition constitutes a privileged therapeutic solution to treat skin hyperpigmentation, a major dermatological concern associated with the overproduction of melanin by human tyrosinase (hsTYR). Despite the existence of many well-known TYR (tyrosinase) inhibitors commercialized in skin formulations, their hsTYR-inhibition efficacy remains poor since most of them were investigated over mushroom tyrosinase (abTYR), a model with low homology relative to hsTYR. Considering the need for new potent hsTYR inhibitors, we designed and synthesized a series of indanones starting from 4-hydroxy compound 1a, one of the two most active derivatives reported to date against the human enzyme, together with marketed thiamidol. We observed that analogues featuring 4-amino and 4-amido-2',4'-dihydroxyindanone motifs showed two-to ten-fold increase in activity over human melanoma MNT-1 cell lysates, and a ten-fold improvement in a 4-days whole-cell experiment, compared to parent analogue 1a. Molecular docking investigation was performed for the most promising 4-amido derivatives and suggested a plausible interaction pattern with the second coordination sphere of hsTYR, notably through hydrogen bonding with Glu203, confirming their impact in the binding mode with hsTYR active site.

Thiamidol containing treatment regimens in facial hyperpigmentation: An international multi-centre approach consisting of a double-blind, controlled, split-face study and of an open-label, real-world study

Objective

Tyrosinase is the rate‐limiting enzyme in melanogenesis. Thiamidol is the most potent inhibitor of human tyrosinase out of 50 000 tested compounds. In clinical studies, it was shown to improve facial hyperpigmentation, post‐inflammatory hyperpigmentation and age spots significantly. To identify the optimal number of daily Thiamidol applications, we conducted a split‐face study comparing the efficacy and tolerability of four‐times with two‐times daily application. Subsequently, we evaluated the efficacy and tolerability of a typical face care regimen containing Thiamidol in a real‐world study.

Methods

The split‐face study was double‐blind, randomized, controlled, including two Thiamidol containing products (serum and day care SPF 30). The serum was applied twice daily on one half of the face and the day care SPF30 twice‐daily on the whole face. The real‐world study was open‐label, observational, including three Thiamidol containing products (day care SPF 30 in the morning, serum and night care in the evening). In both studies, subjects with mild‐to‐moderate facial hyperpigmentation applied the products over 12 weeks. Assessments included clinical and subjective grading of hyperpigmentation, skin condition, hemi‐/modified MASI, chromameter and clinical photography.

Results

In the split‐face study (n = 34), hyperpigmentation, skin roughness and hMASI improved all significantly (P < 0.001) versus baseline, with first visible results after two weeks of twice‐daily application. The four‐times daily application led to significant improvement versus the two‐times daily application. In the real‐world study (n = 83), all evaluated parameters, including skin condition and chromametry (n = 30), improved significantly (P < 0.001) in comparison with baseline and the corresponding preceding visits. The subjects judged the cosmetic properties of the products positively. In both studies, the products were well tolerated.

Conclusion

Four‐times daily Thiamidol improves facial hyperpigmentation significantly more than two‐times daily and is well tolerated by the subjects. The real‐world study with a typical face care regimen containing Thiamidol shows improvement of facial hyperpigmentation and confirms tolerability. Furthermore, the data provide evidence for the suitability of this three‐product Thiamidol regimen for day‐to‐day life.

Effective reduction of post-inflammatory hyperpigmentation with the tyrosinase inhibitor isobutylamido-thiazolyl-resorcinol (Thiamidol)

Objective

Post‐inflammatory hyperpigmentation (PIH) is a major cosmetic concern especially in individuals with darker skin complexion. Unfortunately, treatment with anti‐inflammatory ingredients alone does not prevent the development of hyperpigmented spots. Recently, isobutylamido‐thiazolyl‐resorcinol (Thiamidol) was described as a very potent inhibitor of human tyrosinase. The objective of this research was to investigate the potential of this compound to prevent PIH induced by epidermal wounding (suction blister) and related to acne.

Methods

Suction blister‐induced PIH was treated with a formulation containing Thiamidol or a vehicle for 3 months, and the changes in hyperpigmentation were monitored by spectroscopic measurements. The effect of skin care formulations containing Thiamidol on acne‐related PIH was investigated in two studies, a vehicle‐controlled, double‐blinded, randomized clinical study and a clinical observational study. Both studies had a duration of 3 months and included assessments such as clinical photography, clinical grading and melanin index measurements.

Results

Already after 2 weeks of treatment, suction blister sites treated with Thiamidol were significantly lighter than control sites and improved throughout the treatment period. Subjects´ self‐grading demonstrated that Thiamidol significantly improved the visibility of acne‐induced hyperpigmentation compared to the vehicle treatment. A skin care regimen with Thiamidol significantly improved acne‐related PIH over 12 weeks shown by Mexameter measurements, expert grading, self‐grading and clinical photography.

Conclusion

Thiamidol represents a safe and effective ingredient for cosmetic products against post‐inflammatory hyperpigmentation.