The role of topical retinoids in the treatment of pigmentary disorders: an evidence-based review

Melasma: A Step-by-Step Approach Towards a Multimodal Combination Therapy

Melasma is a common challenge in the field of pigmentary skin disorders, exerting a significant emotional and psychosocial burden on patients. The persistent and recurring nature of melasma complicates its management in routine clinical practice. This comprehensive review outlines a stepwise, practical approach encompassing diagnostic, preventive and therapeutic strategies for the management of melasma. A thorough exploration of aggravating and exacerbating factors, including sun exposure, hormonal imbalances, photosensitizing medication and cosmetics, is essential for a holistic assessment of the disease. With an emphasis on consistent and effective photoprotection, initial topical treatment modalities target the melanin production and/or the transfer of melanosomes to keratinocytes. Topical tyrosine inhibitors emerge as the first choice for reducing and preventing hyperpigmentation, with compounds such as thiamidol or tranexamic acid (TXA) being preferred for their safety profile over hydroquinone (HQ), kojic acid and arbutin. Combination with chemical peels can further enhance the therapeutic efficacy, even in cases with resistant melasma. In more severe cases, laser- and light-based interventions may be considered, but with the caveat of the likelihood of recurrence within 3-6 months. Assisted TXA delivery, via either fractional non-ablative laser or microneedling techniques, can further improve clinical outcomes. In conclusion, an optimal melasma management strategy is a multimodal approach, which includes effective photoprotection and a mix of different topical treatments targeting melanin synthesis, the anti-inflammatory environment, senescence and vascularity. Complementary procedures, such as chemical peels, and laser, light-based or microneedling procedures, with or without TXA, can further expedite melanin clearance in more severely affected instances. Individual discussions with patients regarding treatment expectations, recurrence likelihood and potential side effects are paramount to a comprehensive and successful therapeutic journey.

Understanding Melasma-How Can Pharmacology and Cosmetology Procedures and Prevention Help to Achieve Optimal Treatment Results? A Narrative Review

Melasma is a chronic skin condition that involves the overproduction of melanin in areas exposed to ultraviolet radiation. Melasma treatment is long-term and complicated with recurrence and resistance to treatment. The pathogenesis of melasma is highly complex with multiple pathologies occurring outside of the skin pigment cells. It includes photoaging, excessive melanogenesis, an increased number of mast cells, increased vascularization, and basement membrane damage. In addition, skin lesions related to melasma and their surrounding skin have nearly 300 genes differentially expressed from healthy skin. Traditionally, melasma was treated with topical agents, including hydroquinone, tretinoin, glucocorticosteroids and various formulations; however, the current approach includes the topical application of a variety of substances, chemical peels, laser and light treatments, mesotherapy, microneedling and/or the use of systemic therapy. The treatment plan for patients with melasma begins with the elimination of risk factors, strict protection against ultraviolet radiation, and the topical use of lightening agents. Hyperpigmentation treatment alone can be ineffective unless combined with regenerative methods and photoprotection. In this review, we show that in-depth knowledge associated with proper communication and the establishment of a relationship with the patient help to achieve good adherence and compliance in this long-term, time-consuming and difficult procedure.

Implications of Oxidative Stress in the Pathogenesis and Treatment of Hyperpigmentation Disorders

Oxidative stress represents an imbalance between the generation of reactive oxygen and nitrogen species and the ability of antioxidant systems to decompose those products. Oxidative stress is implicated in the pathogenesis of hyperpigmentation, hypopigmentation, melanoma, and other skin diseases. Regulatory networks involving oxidative stress and related pathways are widely represented in hypopigmentation diseases, particularly vitiligo. However, there is no complete review into the role of oxidative stress in the pathogenesis of hyperpigmentation disorders, especially regarding associations involving oxidative stress and cellular signaling pathways. Here, we review oxidative and antioxidant systems, oxidative stress-induced signal transduction mechanisms, and effects of antioxidant drugs used in preclinical and clinical settings in hyperpigmentation disorders.

Efficacy of topical cysteamine hydrochloride in treating melasma: a systematic review

INTRODUCTION

Melasma remains a recurrent, chronic, therapeutically challenging, and psychologically burdening condition. Several different modalities and approaches have been utilized, and some with notable success to experimentally manage the condition. Cysteamines, with their depigmentation properties, have only recently been intensely studied. One such formulation is the topical 5% cysteamine hydrochloride, the structure of which is notably more stable and with a less foul odor than its prior counterparts. We, therefore, aimed to assess the efficacy of the mentioned formulation in the treatment of melasma.

METHODS

The PubMed, SCOPUS, ISI Web of Science, and Embase, Cochrane, and Proquest databases were thoroughly searched for English studies evaluating the effects of the topical agent mentioned.

RESULTS

Eight studies (five RCTs, two case reports, and one case series) were included after three rounds of screening, most of which were carried out in Iran. Statistical significance was noted when assessing decreased melanin content and satisfaction rates.

CONCLUSIONS

It appears that the cysteamine cream could be comparably efficient in treating melasma while accompanied only by minor and transient adverse events. However, current evidence is limited by insufficient sample size, long-term follow-up, and only to epidermal melasma, highlighting the need for appropriately designed randomized controlled clinical trials to draw a conclusive image of the cysteamine's role in treating this recalcitrant condition.

Periorbital Discolouration Diagnosis and Treatment: Evidence-Based Review

Infraorbital dark circles are a significant esthetic concern with few publications however offering evidence-based recommendations for their classification and consequent management. A literature review has been undertaken to classify dark circles based on etiology: shadowing, vascular, idiopathic hyperpigmentation, post-inflammatory hyperpigmentation, constitutional and offer an analysis of current treatment modalities and their effectiveness in managing specific types of infraorbital circles. This review aims to provide a detailed account of dark circle etiology, assessment and management.

Formulation approaches for improved retinoids delivery in the treatment of several pathologies

Retinoid acid (RA) and other retinoids are extensively used as therapeutic agents in the treatment of several types of cancer and skin disorders. However, the efficiency of these medical agents is compromised due to the unsatisfactory concentration of retinoids in the target cells/tissues. Furthermore, severe side-effects are related to retinoids administration. Incorporation of retinoids into carrier-based delivery systems using encapsulation technology has been proposed in order to overcome the limitations of using free retinoids in the treatment of several pathologies. The present work starts exploring the competences and the difficulties of using retinoids in health care. The metabolism and the main considerations about the mechanism of action of retinoids are also discussed. The final sections are focused on the most recent studies about RA controlled delivery systems to be used in the medical field.

Evaluation of the safety and efficacy of a triple combination cream (hydroquinone, tretinoin, and fluocinolone) for treatment of melasma in Middle Eastern skin

Background: Melasma is the most common pigmentary skin disorder, especially in females and those with darker complexion. The current study evaluated the safety and efficacy of a triple combination cream containing hydroquinone 4%+tretinoin 0.05%+fluocinolone acetonide 0.01% (Januluma^® cream produced by Janus Pharmaceutical Co, Tehran, Iran) in the treatment of melasma.

Patients and methods: Twenty-two female volunteers (mean±standard deviation of age: 39.20±4.16 years) who fulfilled the eligibility criteria participated in this study after signing the informed consent. They were requested to apply the Januluma^®cream every night for 8 weeks. Modified melasma area and severity index (mMASI), skin lightness (L value), and severity of pigmentation (E value) by Visio Face, and skin biophysical parameters including pH, melanin index, erythema index, sebum, hydration, trans epidermal water loss, thickness and density of epidermis, and dermis (using 22 MHz ultrasonography) were measured before and 4 and 8 weeks after treatment. Also patients’ satisfaction was assessed 4 and 8 weeks after treatment using visual analog score.

Results: mMASI decreased significantly from 3.37 to 2.60 at week 4, and to 2.40 at week 8 (P-values=0.00 and 0.01, respectively). Also, E and L values improved significantly after 8 weeks of treatment (P=0.01 and 0.00, respectively). Skin melanin index decreased from 237.49 AU to 196.30 AU at week 8 (P=0.01). Also echo density of dermis increased significantly after 8 weeks of treatment (P=0.029). Almost all participants experienced some degrees of pruritus, scaling, and erythema, esspecially during the first month of application, which were generally mild and tolerable. The mean satisfaction of patients with the treatment was 6.77.

Conclusion: The triple combination formula was reasonably safe and effective for treatment of melasma in Middle Eastern patients.

Comparison of the efficacy and safety of 0.1% adapalene gel and 0.025% tretinoin cream in the treatment of childhood acanthosis nigricans

BACKGROUND

There have been few published randomized controlled trials for the treatment of childhood acanthosis nigricans (AN) to date.

OBJECTIVE

To assess the efficacy of topical 0.1% adapalene gel compared to 0.025% tretinoin cream in the treatment of childhood AN.

METHODS

An 8-week, randomized, split-neck, comparative study between topical 0.1% adapalene gel and 0.025% tretinoin cream for the treatment of neck hyperpigmentation associated with AN was performed. M index measured by a narrowband reflectance spectrophotometer and both investigator's global evaluation (IGE) and parent's global evaluation (PGE) scales were used to evaluate efficacy.

RESULTS

There was no statistically significant difference between 0.1% adapalene gel and 0.025% tretinoin cream in the treatment of AN-associated hyperpigmentation (P = 0.56). Mean differences in M indices between week 0 and week 8 of 0.1% adapalene and 0.025% tretinoin treatment were 24.2 ± 7.9% and 23.8 ± 8.3% improvement, respectively. Regarding treatment efficacy, 90.0% and 85.0% of participants had more than 75% improvement in IGE in 0.1% adapalene and 0.025% tretinoin treatment sides, respectively. In addition, 75.0% and 65.0% of participants had more than 75.0% improvement in PGE in 0.1% adapalene and 0.025% tretinoin treatment sides, respectively.

LIMITATIONS

Lack of histopathological evaluations.

CONCLUSIONS

We found no significant difference between topical 0.1% adapalene gel and 0.025% tretinoin in the treatment of AN.

Melasma: Updates and perspectives

Management of melasma is highly challenging due to inconsistent treatment results and frequent relapses. However, recent studies revealed that melasma may not only be a disease of melanocytes, but also a photoaging skin disorder. Herein, we attempt to validate that melasma is indeed a photoaging disorder by presenting the histopathologic findings of melasma: solar elastosis, altered basement membrane, increased vascularization and increased mast cell count. We also provide some therapeutic implications based on these findings and a discussion on the latest updates and perspectives regarding treatment.

Postinflammatory Hyperpigmentation: Epidemiology, Clinical Presentation, Pathogenesis and Treatment

Postinflammatory hyperpigmentation (PIH) is a reactive hypermelanosis that develops following cutaneous inflammation. Common causes of PIH include intrinsic skin conditions (e.g., acne and eczema) as well as external insults to the skin, such as burn injuries and dermatologic procedures. PIH more commonly occurs in individuals with darker skin, for whom it is often a source of significant psychological distress. Several therapeutic modalities are available for the treatment of PIH, including topical agents, chemical peels, and energy-based devices. We review the epidemiology, clinical presentation, pathogenesis, and treatment of PIH.

Heterogeneous Pathology of Melasma and Its Clinical Implications

Melasma is a commonly acquired hypermelanosis that affects sun-exposed areas of the skin, with frequent facial involvement. Its histologic manifestations are evident in the epidermis, extracellular matrix, and dermis. In addition to epidermal pigmentation, pathologic findings of melasma include extracellular matrix abnormality, especially solar elastosis. The disrupted basement membrane has been described in melasma with variable incidences. In the dermis, an increase in vascularity and an increase in the number of mast cells were observed, indicating that dermal factors have critical roles in the pathogenesis of melasma, despite the fact that melasma is characterized by epidermal hyperpigmentation. This review discusses such histologic characteristics of melasma, with consideration to their implications for melasma treatment.

Acquired hyperpigmentations

Cutaneous hyperpigmentations are frequent complaints, motivating around 8.5% of all dermatological consultations in our country. They can be congenital, with different patterns of inheritance, or acquired in consequence of skin problems, systemic diseases or secondary to environmental factors. The vast majority of them are linked to alterations on the pigment melanin, induced by different mechanisms. This review will focus on the major acquired hyperpigmentations associated with increased melanin, reviewing their mechanisms of action and possible preventive measures. Particularly prominent aspects of diagnosis and therapy will be emphasized, with focus on melasma, post-inflammatory hyperpigmentation, periorbital pigmentation, dermatosis papulosa nigra, phytophotodermatoses, flagellate dermatosis, erythema dyschromicum perstans, cervical poikiloderma (Poikiloderma of Civatte), acanthosis nigricans, cutaneous amyloidosis and reticulated confluent dermatitis

Treatment of facial post-burn hyperpigmentation using micro-plasma radiofrequency technology

Management of facial post-burn hyperpigmentation is a common and challenging problem for dermatologists and plastic surgeons. The recent development of micro-plasma radiofrequency technology, which allows precise and rapid treatment with controlled thermal injury, can be an effective treatment of post-burn hyperpigmentation. This study aimed to evaluate the effectiveness and complications of micro-plasma radiofrequency treatment of post-burn hyperpigmentation. The study included 35 patients with Fitzpatrick skin type III or IV and facial post-burn hyperpigmentation. Patients received three to five treatments at 8-week intervals. A roller tip was used with the power setting at 60-90 W, and 3-4 passes were made in different directions. The degree of improvement and complications were recorded. Improvement of hyperpigmentation was evaluated by patient self-assessment and by plastic surgeons who compared digital photographs taken before treatment and 2 months after the last treatment. The results showed that post-burn hyperpigmentation responded favorably to micro-plasma radiofrequency treatment with very few complications. The average pain score using a visual analog scale from 0 to 10 was 6.7 ± 0.7. After a series of treatments, 32 of the 35 patients had achieved a >51% improvement of their hyperpigmentation, and 3 patients had achieved a fair improvement. The mean score for improvement of hyperpigmentation was 4.28. Patient self-evaluations indicated good satisfaction with the cosmetic outcomes, and some softening of the scars. Micro-plasma radiofrequency technology is appropriate, effective, and safe for the treatment of facial post-burn hyperpigmentation, and provides a promising noninvasive treatment for superficial facial injuries.

Treatment of refractory melasma with combination of topical 5% magnesium ascorbyl phosphate and fluorescent pulsed light in Asian patients

BACKGROUND

Melasma is an acquired disorder of hypermelanosis of great psychosocial concern. The treatments with various conventional therapies are often unsatisfactory. Lasers and light sources have been used to treat pigmented lesions, but in Asian skin with higher melanin content, such treatments may be challenging.

OBJECTIVES

To determine the effectiveness of treating melasma with a combination of topical 5% magnesium ascorbyl phosphate (MAP) and fluorescent pulsed light (FPL).

MATERIALS AND METHODS

Patients of skin types III-V with refractory melasma were treated for 12 weeks with topical application of 5% MAP and three sessions of FPL (570-950 nm) at 3, 6, and 9 weeks (fluence 12-14 J/cm(2) , pulse width 15 ms, and spot size 3 cm(2) ). They were followed up for another 12 weeks to assess the persistence of treatment benefit. Digital photographs of the patients were taken at each visit. Treatment efficacy was determined by calculating mean melasma area and severity index (MASI) at the beginning and then at weeks 6, 12, and 24. The subjective assessment was done by comparing pre-treatment and post-treatment photographs by an independent observer and self-assessment by patients using four-point scoring scale (1, poor, 2, fair, 3, good, and 4, excellent).

RESULTS

Sixty-five patients completed the study. The baseline mean MASI score of 14.80 decreased to 4.53 at the 12th week (end of treatment) and 6.35 at the 24th week (end of follow-up). The overall regression of mean MASI at these end-points was 69.3% and 57% (P < 0.01). The pre- and post-treatment photographic evaluation by independent observer and patients' self-assessment at the 12th week showed good to excellent response (scores 3 and 4) in 52.3% and 44.6% cases, respectively. No significant adverse effects of treatment were noted.

CONCLUSION

Combination of 5% MAP with FPL is effective, well tolerated, and safe in treating refractory melasma in Asian patients but for persistent improvement, maintenance treatments would be required.

Topical hypopigmenting agents for pigmentary disorders and their mechanisms of action

Melanin is produced in melanocytes and stored in melanosomes. In spite of its beneficial sun-protective effect, abnormal accumulation of melanin results in esthetic problems. Hydroquinone, competing with tyrosine, is a major ingredient in topical pharmacological agents. However, frequent adverse reactions are amongst its major limitation. To solve this problem, several alternatives such as arbutin, kojic acid, aloesin, and 4-n-butyl resorcinol have been developed. Herein, we classify hypopigmenting agents according to their mechanism of action; a) regulation of enzyme, which is subdivided into three categories, i) regulation of transcription and maturation of tyrosinase, ii) inhibition of tyrosinase activity, and iii) post-transcriptional control of tyrosinase; b) inhibition of melanosome transfer, and c) additional mechanisms such as regulation of the melanocyte environment and antioxidant agents.

What should be considered in treatment of melasma

Melasma is a common acquired hyperpigmentary skin disorder characterized by light to dark brown macules and patches occurring in the sun-exposed areas of the face. Melasma lesional skin is characterized by epidermal hyperpigmentation through increased melanogenesis in epidermal melanocytes. Some patients have dermal melanin but its amount is not significant and its distribution is very heterogeneous in the whole melasma lesional skin. Melasma is not homogeneous disease and there are personal characteristics of patients with melasma. The pathogenesis of melasma is not fully understood, but several hypotheses have been suggested. Increased vascularity in melasma lesions has suggested the role of increased number of enlarged vessels in the development of melasma. Endogeneous and exogeneous stimuli such as sex hormones and ultraviolet irradiation respectively may stimulate the microenvironment leading to the release of various mediators that cause activation of melanocytes and/or these stimuli may directly activate the melanocytes. Melasma patients may have specialized melanocytes with an intrinsic sensitivity to these stimuli.

Anti-pigmentary activity of fucoxanthin and its influence on skin mRNA expression of melanogenic molecules

OBJECTIVES

Carotenoids and retinoic acid derivatives are topically applied for sun-protective and whitening purposes. Fucoxanthin is a carotenoid derived from edible sea algae, but its effect on melanogenesis has not been established. Therefore, we examined the effect of fucoxanthin on melanogenesis.

METHODS

Inhibitory effects on tyrosinase activity, melanin formation in B16 melanoma and skin pigmentation in UVB-irradiated guinea-pigs were evaluated. To elucidate the action of fucoxanthin on melanogenesis, its effect on skin melanogenic mRNA expression was evaluated in UVB-irradiated mice. Fucoxanthin was given topically or orally to mice once a day and UVB irradiation was applied for 14 days. The effect of fucoxanthin on skin melanogenic mRNA expression was evaluated by real time reverse transcription polymerase chain reaction.

KEY FINDINGS

Fucoxanthin inhibited tyrosinase activity, melanogenesis in melanoma and UVB-induced skin pigmentation. Topical application of fucoxanthin (1%) significantly suppressed mRNA expression of cyclooxygenase (COX)-2, endothelin receptor A, p75 neurotrophin receptor (NTR), prostaglandin E receptor 1 (EP1), melanocortin 1 receptor (MC1R) and tyrosinase-related protein 1. The suppression of p75NTR, EP1 and MC1R expressions was observed at 0.01% application. Also, oral application of fucoxanthin (10 mg/kg) significantly suppressed expression of COX-2, p75NTR, EP1 and MC1R.

CONCLUSIONS

These results suggest that fucoxanthin exhibits anti-pigmentary activity by topical or oral application in UVB-induced melanogenesis. This effect of fucoxanthin may be due to suppression of prostaglandin (PG) E(2) synthesis and melanogenic stimulant receptors (neurotrophin, PGE(2) and melanocyte stimulating hormone expression).