Intermittent therapy for melasma in Asian patients with combined topical agents (retinoic acid, hydroquinone and hydrocortisone): clinical and histological studies

Definition of refractory melasma and its treatment: a review

Although patients with refractory melasma have been treated using various methods, there is still no precise definition or summary of the therapies. To define refractory melasma and conduct a review of the treatments, we searched for relevant publications in PubMed, Web of Science, and the Cochrane Library, and a total of 35 references were obtained. Refractory melasma can be roughly defined as an ineffective treatment for melasma, including topical bleaching agents, chemical peels, laser therapy, microdermabrasion for more than six months, or chemical peels treated more than six times. Meanwhile, physicians should be careful when treating patients with darker skin and dermal or mixed types of melasma since these individuals do not respond well to treatment. Lasers combined with other methods, especially different types of lasers or topical agents, are considered more effective than monotherapy. Oral tranexamic acid (TXA) is a prospective cure for refractory melasma. Other methods include a combination of chemical peels, microneedling, or injections with additional therapies. In conclusion, we were able to provide a rough definition of refractory melasma and list the available therapies. According to the literature, the most prevalent treatment is laser combination therapy. However, laser treatment should be considered only after topical agents and chemical peeling have failed. Considering its side effects, efficacy, and safety, oral TXA may be a better option, but more research is needed to make a firm conclusion. Moreover, maintenance therapy is required after treatment.

Best practices in the treatment of melasma with a focus on patients with skin of color

BACKGROUND

Melasma is a chronic hypermelanosis of the skin that affects approximately 1% of the global population, predominantly affects women, and is more prevalent in skin of color. Melasma is a common driver for patients with skin of color to seek out a dermatologist for treatment, and ensuring the right approach for these patients is important because some treatments may be associated with adverse side effects. Because of the chronicity of the disease and established psychosocial and emotional impacts, there is a large need to ensure care follows the best available evidence on the treatment of patients with melasma.

OBJECTIVE

Here, we summarized current available topical treatments for melasma with considerations dermatologists should have for their patients with skin of color.

METHODS

Steering committee consensus on clinical best practices.

RESULTS

We describe a flexible and focused treatment algorithm that reflects both treatment and maintenance periods that is a consensus of our extensive clinical experience.

LIMITATIONS

Use of real-world evidence and potential for individual practice bias.

CONCLUSION

Melasma can be challenging to treat, particularly in patients with skin of color, and our recommendations for best practices for patients in the United States are an important step toward standardizing care.

Disorders of hyperpigmentation. Part II. Review of management and treatment options for hyperpigmentation

Key challenges in the management of pigmentary disorders such as melasma and postinflammatory hyperpigmentation are their resistance to treatment, tendency to recur after treatment, and the risk of exacerbating hyperpigmentation with many treatment modalities. The second article in this 2-part continuing medical education series on pigmentary disorders focuses on the evidence behind medical and procedural treatments of dyschromias, including photoprotection, topical lightening agents, oral agents, chemical peels, and laser therapy.

Natural skin-whitening compounds for the treatment of melanogenesis (Review)

Melanogenesis is the process for the production of melanin, which is the primary cause of human skin pigmentation. Skin-whitening agents are commercially available for those who wish to have a lighter skin complexions. To date, although numerous natural compounds have been proposed to alleviate hyperpigmentation, insufficient attention has been focused on potential natural skin-whitening agents and their mechanism of action from the perspective of compound classification. In the present article, the synthetic process of melanogenesis and associated core signaling pathways are summarized. An overview of the list of natural skin-lightening agents, along with their compound classifications, is also presented, where their efficacy based on their respective mechanisms of action on melanogenesis is discussed.

Depigmentation and Anti-aging Treatment by Natural Molecules

Natural molecules are becoming more accepted choices as cosmetic agents, many products in the market today claim to include natural components. Plants include many substances that could be of a value in the whitening of the skin and working as anti-aging agents. A wide range of articles related to natural skin whitening and anti-aging agents have been reviewed. Many plant-derived and natural molecules have shown to affect melanin synthesis by different mechanisms, examples include Arbutin, Ramulus mori extract, Licorice extract, Glabridin, Liquiritin, Kojic acid, Methyl gentisate, Aloesin, Azelaic acid, Vitamin C, Thioctic acid, Soya bean extracts, Niacinamide, α and β-hydroxy acids, Lactic acid, Chamomile extract, and Ellagic acid. Some of the widely used natural anti-aging products as natural antioxidants, collagen, hyaluronic acid, and coenzyme Q can counteract the effects of reactive oxygen species in skin cells and have anti-aging properties on the skin. It was concluded that many natural products including antioxidants can prevent UV-induced skin damage and have whitening and anti-aging effects. It is very important to develop and stabilize appropriate methods for the evaluation of the whitening and anti-aging capacity of natural products and their exact mechanism of action to ensure real efficacy based on evidence-based studies. The attention should be oriented on the formulations and the development of an appropriate vehicle to ensure suitable absorption of these natural products in addition to evaluating the suitable concentration of these molecules required having the desired effects without causing harmful side effects.

Effectiveness of a new cosmetic treatment for melasma

BACKGROUND

Melasma treatment is difficult due to extended treatment periods, suboptimal adherence, inconsistent results, and frequent relapses. Kojic acid has been shown to be effective in reducing melasma severity and is now increasingly used in cosmetic treatments.

AIMS

The purpose of the present study was to evaluate the effectiveness of a new cosmetic treatment for melasma at 45 and 90 days.

METHODS

Multicenter prospective study across 20 dermatology clinics/ambulatories. One hundred patients with mild-to-moderate melasma were evaluated. The primary endpoints were changes in mean modified melasma area and severity index (mMASI) score and patient-reported satisfaction at 45 and 90 days.

RESULTS

The mean age of patients was 45.19 ± 11.5 years. Most patients were female and Caucasian. Patients presented mixed (65%), epidermal (26%), and dermal (4%) types of melasma. Triggering factors were hormonal contraception (33%), pregnancy (31%), and pharmacological treatment (11%); mean disease duration was 6.7 ± 6.8 years. Overall, a statistically significant decrease in mean mMASI scores was seen at 45 (2.19 ± 0.182 vs 3.29 ± 0.267, P < .0001) and 90 days (1.27 ± 0.128 vs 3.29 ± 0.267, P < .00001). The highest reduction in mMASI scores was observed in patients with dermal melasma. IGA scores showed a statistically significant improvement in pigmentation at 90 days (P < .00001).

CONCLUSION

The novel cosmetic treatment was associated with the improvement of melasma, as assessed by mMASI.

Melasma: an Up-to-Date Comprehensive Review

Melasma is a common acquired condition of symmetric hyperpigmentation, typically occurring on the face, with higher prevalence in females and darker skin types. Multiple etiologies, including light exposure, hormonal influences, and family history, have been implicated in the pathogenesis of this disorder. Overall prevalence ranges widely at 1-50%, since values are typically calculated within a specific ethnic population within a geographic region. Histologically, melasma can display increased epidermal and/or dermal pigmentation, enlarged melanocytes, increased melanosomes, solar elastosis, dermal blood vessels, and, occasionally, perivascular lymphohistiocytic infiltrates. Various topical, oral, and procedural therapies have been successfully used to treat melasma. Traditional topical therapies including hydroquinone, tretinoin, corticosteroids, and triple combination creams; however, other synthetic and natural topical compounds have also shown varying efficacies. Promising oral therapies for melasma include tranexamic acid, Polypodium leucotomos, and glutathione. Procedures, including chemical peels, microneedling, radiofrequency, and lasers, are also often used as primary or adjunctive treatments for melasma. Notably, combination therapies within or across treatment modalities generally result in better efficacies than monotherapies. This review serves as a comprehensive update on the current understanding of the epidemiology, pathogenesis, clinical and histologic features of melasma, as well as treatments for this common, yet therapeutically challenging, condition.

A Retrospective Analysis of the Treatment of Melasma Using a Fractional Long-Pulsed Alexandrite Laser in Korean Patients

BACKGROUND

Long-pulsed, 755-nm, alexandrite lasers have been shown to be effective and safe in the treatment of pigmentary lesions.

OBJECTIVE

Clinical outcomes and side effects in the treatment of melasma using a fractional, long-pulsed, alexandrite laser were assessed.

MATERIALS AND METHODS

Forty-eight patients with melasma received 2 to 4 treatment sessions of fractional, long-pulsed, alexandrite laser at 2 to 3 weeks intervals. The parameter of treatment was 60 to 80 J/cm without dynamic cooling device using 15-mm spot size of fractional hand piece, with a 0.5- to 1-millisecond pulse width.

RESULTS

The mean modified melasma area and severity index score decreased significantly 2 months after the final treatment compared with baseline (16.5 ± 8.2 vs 11.5 ± 7.0; p = .002). The patients with epidermal type melasma were more effective compared to dermal type (p < .001).

CONCLUSION

Long-pulsed alexandrite lasers using a fractional hand piece are moderately effective in the treatment of melasma with low risk of adverse effects, and it is suggested that fractional, long-pulsed, alexandrite laser with combination of other modalities can be an additional therapeutic option in patients with melasma.

Inorganic layered double hydroxides as a 4-hexyl resorcinol delivery system for topical applications

In this study, the hydrophobic even skin tone active, 4-hexylresorcinol is intercalated into a Zn–Al layered double hydroxide by co-precipitation method and used as controlled release ingredient in a skin care formulation.

Evidence-based treatment for melasma: expert opinion and a review

Introduction

Melasma is one of the most common pigmentary disorders seen by dermatologists and often occurs among women with darker complexion (Fitzpatrick skin type IV–VI). Even though melasma is a widely recognized cause of significant cosmetic disfigurement worldwide and in India, there is a lack of systematic and clinically usable treatment algorithms and guidelines for melasma management. The present article outlines the epidemiology of melasma, reviews the various treatment options along with their mode of action, underscores the diagnostic dilemmas and quantification of illness, and weighs the evidence of currently available therapies.

Methods

A panel of eminent dermatologists was created and their expert opinion was sought to address lacunae in information to arrive at a working algorithm for optimizing outcome in Indian patients. A thorough literature search from recognized medical databases preceded the panel discussions. The discussions and consensus from the panel discussions were drafted and refined as evidence-based treatment for melasma. The deployment of this algorithm is expected to act as a basis for guiding and refining therapy in the future.

Results

It is recommended that photoprotection and modified Kligman’s formula can be used as a first-line therapy for up to 12 weeks. In most patients, maintenance therapy will be necessary with non-hydroquinone (HQ) products or fixed triple combination intermittently, twice a week or less often. Concomitant camouflage should be offered to the patient at any stage during therapy. Monthly follow-ups are recommended to assess the compliance, tolerance, and efficacy of therapy.

Conclusion

The key therapy recommended is fluorinated steroid containing 2–4% HQ-based triple combination for first line, with additional selective peels if required in second line. Lasers are a last resort.

Electronic supplementary material

The online version of this article (doi:10.1007/s13555-014-0064-z) contains supplementary material, which is available to authorized users.

Low-power fractional CO₂ laser versus low-fluence Q-switch 1,064 nm Nd:YAG laser for treatment of melasma: a randomized, controlled, split-face study

BACKGROUND

Various laser treatments are currently available for melasma but their use remains challenging because of potential side effects.

OBJECTIVE

The aim of this randomized controlled study was to compare the efficacy and safety of low-fluence Q-switch 1,064 nm Nd:YAG and low-power fractional CO2 laser using a split-face design.

MATERIALS AND METHODS

A total of 40 female patients with symmetric melasma were enrolled to the study and each side of their face was randomly allocated to either low-fluence Q-switch 1,064 nm Nd:YAG or low-power fractional CO2 laser. They were treated every 3 weeks for five consecutive sessions and followed for 2 months after the last treatment session. Response to treatment was assessed using the Melanin Index (MI) score, modified Melasma Area and Severity Index (mMASI) score, and a subjective self-assessment method.

RESULTS

At the 2-month follow-up visit, both sides of the face had statistically significant reductions in the MI and mMASI scores compared with the first visit (p < 0.001). The differences between the mean MI and mMASI scores at baseline and at 2-month follow-up were compared between the two treatments and results showed that the reduction of MI and mMASI score in the fractional CO2 laser-treated side was significantly more than on the Q-switch 1,064 nm Nd:YAG laser-treated side (p < 0.001). There were no significant adverse effects with either of the laser treatments.

CONCLUSION

The present study shows that low-power fractional CO2 laser is safe and effective and can be considered as a valuable approach in the treatment of melasma.

A clinical study of melasma and a comparison of the therapeutic effect of certain currently available topical modalities for its treatment

BACKGROUND

Melasma is a common acquired facial hypermelanosis. Conventional treatment of melasma includes a sunscreen and hypopigmenting agents. The treatment of this recalcitrant disorder is often difficult and unsatisfactory.

AIMS

The objective is to carry out a detailed clinical study of melasma and to assess the therapeutic effect and side effects of certain currently available topical modalities for the treatment of melasma.

MATERIALS AND METHODS

160 patients of all age groups and both sexes were treated sequentially with five different combination regimes for 3 months. Assessment of the response was done subjectively as well as by melasma area and severity index (MASI).

RESULTS

Out of the five modalities studied, the modified Kligman's formula was the most effective. However, it had comparatively higher incidence of side effects.

CONCLUSIONS

Among the currently available topical modalities for the treatment of melasma, the most effective combination is the modified Kligman's formula. However, in view of the side effects it causes, it must be used with caution and proper counseling.

Intense Pulsed Light and Low-Fluence Q-Switched Nd:YAG Laser Treatment in Melasma Patients

Background

Recently, low fluence collimated Q-switched (QS) Nd:YAG laser has drawn attention for the treatment of melasma. However, it needs a lot of treatment sessions for the substantial results and repetitive laser exposures may end up with unwanted depigmentation.

Objective

We evaluated the clinical effects and safety of the combinational treatment, using intense pulsed light (IPL) and low fluence QS Nd:YAG laser.

Methods

Retrospective case series of 20 female patients, with mixed type melasma, were analyzed using medical records. They were treated with IPL one time, and 4 times of weekly successive low fluence Nd:YAG laser treatments. At each visit, digital photographs were taken under the same condition. Melanin index (MI) and erythema index (EI) were measured on the highest point on the cheekbones. Modified melasma area and severity index (MASI) scores were calculated by two investigators using digital photographs.

Results

The mean values of MI and EI decreased significantly after treatments. The modified MASI score has decreased by 59.35%, on average. Sixty percents of the participants did not require any more treatments, and no clinical aggravations were observed during the follow-up period (mean 5.9 months).

Conclusion

IPL and low fluence laser may elicit a clinical resolution in the mixed type melasma with long term benefits.

Melasma in Latin America: options for therapy and treatment algorithm

OBJECTIVE/AIM

To examine approaches to therapy for melasma in Latin Americans and to propose treatment algorithms for patients with mild, moderate and severe melasma.

BACKGROUND

Melasma is prevalent in up to 10% of the Latin American population. It is found in all racial groups and is more common in subjects with darker skin phototypes. A number of topical treatments and procedures have been used for melasma. Topical treatments containing hydroquinone are the most popular. Care must be taken when treating melasma to avoid inducing post-inflammatory hyperpigmentation and ochronosis. Determination of the severity of melasma (using the Melasma Area Severity Index and/or Physician's Global Assessment) and choice of the most effective and suitable treatment and/or procedure for individual patients is therefore essential. Sun protection is mandatory for all melasma patients.

METHODS

Thirty-one clinical studies of topical treatments, chemical peels and laser and other therapies used for treating melasma were assessed for the level and quality of clinical evidence, by the Latin American Pigmentary Disorders Academy. The results of this analysis were combined with differential diagnosis guidelines and methods for assessing treatment success to establish algorithms for treating mild and moderate-to-severe melasma.

RESULTS

The most appropriate first-line treatment for mild melasma is hydroquinone 4%, triple combination cream containing hydroquinone 4%, tretinoin 0.05% and fluocinolone acetate 0.01%, double combination (e.g. 4% hydroquinone and 0.1% tretinoin) or non-phenolic therapy where there is an allergy to compounds. In moderate-to-severe melasma, triple combination cream is the recommended first-line treatment. Second-line treatment is double combination or hydroquinone 4% where triple therapy is not available or if allergic to compounds. Sun avoidance measures and broad spectrum sunscreens with high SPF are fundamental for the successful management of the disease.

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

Topical retinoids have been used in the treatment of pigmentary disorders such as melasma, actinic lentigines, and postinflammatory hyperpigmentation. This article evaluates the clinical efficacy and tolerability of retinoid treatment for pigmentary disorders through an evidence-based approach. We searched the MEDLINE and The Cochrane Library databases using the keywords 'retinoid' combined with 'melasma,' 'lentigines,' or 'postinflammatory hyperpigmentation.' For each study, the methodology and outcomes were assessed according to specific criteria. There is fair evidence to support the use of topical tretinoin as a monotherapy in the treatment of melasma as well as in the treatment of lentigines (grade B). Adverse effects of topical retinoids are quite frequent, and include local skin irritation, erythema, and peeling, and their severity is mild to moderate. There is evidence to support the use of topical tretinoin in a fixed, triple-combination therapy (hydroquinone 4%/tretinoin 0.05%/fluocinolone acetonide 0.01%) for the treatment of melasma (grade B). There is poor evidence (grade C) to support the use of combination formulations for the treatment of lentigines, and large, randomized, double-blind, controlled trials are needed to further evaluate their use for this indication. In conclusion, there is evidence to support the use of topical retinoids as monotherapy or in combination with other topical agents in the treatment of pigmentary disorders.

A randomized controlled trial of the efficacy and safety of a fixed triple combination (fluocinolone acetonide 0.01%, hydroquinone 4%, tretinoin 0.05%) compared with hydroquinone 4% cream in Asian patients with moderate to severe melasma

BACKGROUND

Melasma is an acquired, chronic hypermelanosis for which therapy remains a challenge.

OBJECTIVES

To compare the efficacy and safety of a triple combination [TC: fluocinolone acetonide 0.01%, hydroquinone (HQ) 4%, tretinoin 0.05%] vs. HQ 4% after 8 weeks of treatment of moderate to severe facial melasma in Asian patients.

METHODS

This was a multicentre, randomized, controlled, investigator-blinded, parallel comparison study. East and South-East Asian patients aged 18 years or older, with a clinical diagnosis of moderate to severe melasma, were enrolled in this study. Patients were enrolled at baseline and treated daily for 8 weeks with TC cream (one application at bedtime) or HQ cream (twice daily). There were four study visits: at baseline and weeks 2, 4 and 8. The primary efficacy variable was the melasma global severity score (GSS). Other outcome measures included Melasma Area and Severity Index, global improvement and patient satisfaction. Safety was assessed through the reporting of adverse events.

RESULTS

TC had superior efficacy to HQ for the primary variable: 77/120 patients (64.2%) on TC had GSS 'none' or 'mild' at week 8 vs. 48/122 patients (39.4%) on HQ (P < 0.001). The secondary efficacy variables confirmed these results. Patient satisfaction was in favour of TC (90/127, 70.8%, vs. 64/129, 49.6%; P = 0.005). More patients had related adverse events on TC (63/129, 48.8%) than on HQ (18/131, 13.7%) but most were mild and none was severe.

CONCLUSIONS

Efficacy in Asians and patient satisfaction were superior with the fixed TC than with HQ 4%.

Peroxisome proliferator-activated receptors (PPARs) and the human skin: importance of PPARs in skin physiology and dermatologic diseases

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear receptor superfamily that regulate lipid, glucose, and amino acid metabolism. More recently, PPARs and corresponding ligands have been shown in skin and other organs to regulate important cellular functions, including cell proliferation and differentiation, as well as inflammatory responses. These new functions identify PPARs and corresponding ligands as potential targets for the treatment of various skin diseases and other disorders. It has been shown that in inflammatory skin disorders, including hyperproliferative psoriatic epidermis and the skin of patients with atopic dermatitis, the expression of both PPARalpha and PPARgamma is decreased. This observation suggests the possibility that PPARalpha and PPARgamma activators, or compounds that positively regulate PPAR gene expression, may represent novel NSAIDs for the topical or systemic treatment of common inflammatory skin diseases such as atopic dermatitis, psoriasis, and allergic contact dermatitis. Moreover, recent findings indicate that PPAR-signaling pathways may act as a promising therapeutic target for the treatment of hyperproliferative skin diseases including skin malignancies. Studies in non-diabetic patients suggest that oral thiazolidinediones, which are synthetic ligands of PPARgamma, not only exert an antidiabetic effect but also may be beneficial for moderate chronic plaque psoriasis by suppressing proliferation and inducing differentiation of keratinocytes; furthermore, they may even induce cell growth arrest, apoptosis, and terminal differentiation in various human malignant tumors. It has been reported that PPARalpha immunoreactivity is reduced in human keratinocytes of squamous cell carcinoma (SCC) and actinic keratosis (AK), while PPARdelta appears to be upregulated. Additionally, the microvessel density is significantly higher in AK and SCC that express high levels of PPARdelta. PPARdelta has been demonstrated to have an anti-apoptotic role and to maintain survival and differentiation of epithelial cells, whereas PPARalpha and PPARgamma activators induce differentiation and inhibit proliferation and regulate apoptosis. In melanoma, the growth inhibitory effect of PPARgamma activation is independent of apoptosis and seems to occur primarily through induction of cell cycle arrest in the G1 phase of the cell cycle or induction of re-differentiation. PPARalpha activation causes inhibition of migration of melanoma cells and anchorage-independent growth, whereas primary tumor growth remains unaltered. In clinical trials of gemfibrozil, a PPARalpha ligand, significantly fewer patients treated with this lipid-lowering drug were diagnosed with melanoma as compared to those in the control group. In conclusion, an increasing body of evidence indicates that PPAR signaling pathways may represent interesting therapeutic targets for a broad variety of skin disorders, including inflammatory skin diseases such as psoriasis and atopic dermatitis, and skin malignancies.

The safety of hydroquinone: A dermatologist's response to the 2006 Federal Register

Recently, the US Food and Drug Administration proposed a ban on over-the-counter hydroquinone mainly on the basis of high absorption, reports of exogenous ochronosis in humans, and murine hepatic adenomas, renal adenomas, and leukemia with large doses over extended time periods. Systemic exposure to hydroquinone from routine topical application is no greater than that from quantities present in common foods. While murine hepatic adenomas increased, murine hepatocellular carcinomas decreased, suggesting a protective effect. Renal tumors are sex, species, and age specific and therefore do not appear relevant to humans after decades of widespread use. Murine leukemia has not been reproducible and would not be expected from small topical doses. Finally, a literature review of exogenous ochronosis and clinical studies employing hydroquinone (involving over 10,000 exposures under careful clinical supervision) reveal an incidence of exogenous ochronosis in the United States of 22 cases in more than 50 years. Therefore, the proposed ban appears to be unnecessarily extreme.

Therapeutical Approaches in Melasma

Melasma (cloasma) is a typical hypermelanosis and a common dermatologic skin disease that involves sun-exposed areas of the skin. It mostly affects women of reproductive age. Solar and ultraviolet exposure are the most crucial etiologic factors. Pregnancy, certain endocrine disorders and hormonal treatments, cosmetics, phototoxic drugs, and antiseizure medications are well-known inducing and exacerbating factors. A classification of melasma is based on Wood's light examination, classifying it in four major clinical types and patterns: epidermal, dermal, mixed, and indeterminate. Different treatment options are currently available for melasma. The choice of proper treatment should take into account the type of melasma to be treated, the skin complexion of the patient, possible previous treatments, the expectations and compliance of the patient, and the season in which the treatment is started.

A comparison of triple combination cream and hydroquinone 4% cream for the treatment of moderate to severe facial melasma

The aim of this study was to compare the efficacy and safety of a triple combination (TC) cream and monotherapy with hydroquinone (HQ) cream in the treatment of moderate to severe facial melasma. A total of 120 patients applied TC cream once daily or HQ cream twice daily for 8 weeks. Evaluations included static global severity assessment of melasma, improvement of melasma over time, local tolerability, and adverse events. TC cream was significantly more effective than HQ cream from week 4 onwards: lesions were approximately equivalent to the surrounding skin in 35% of all TC-treated patients, compared to 5% of those who used HQ cream (P = 0.0001). Improvement of more than 75% was achieved by 73% of TC cream patients and 49% of HQ cream patients (P = 0.007). The incidence of adverse events (erythema, burning sensation, and desquamation) was similar in both groups. No patient dropped out of the study because of drug-related adverse events. TC cream was more effective than the HQ cream for the treatment of moderate to severe facial melasma. Both products had similar safety profiles.

Retinoid therapy of pigmentary disorders

Topical retinoids such as all-trans-retinoic acid (RA), 13-cis-retinoic acid (isotretinoin), retinol, retinaldehyde, tazarotene, and adapalene have been shown to improve dyspigmentation of photodamaged skin including mottling and actinic lentigines. RA monotherapy has also been demonstrated to improve melasma and postinflammatory hypermelanosis. Furthermore, RA in combination with hydroquinone or 4-hydroxyanisole, or azelaic acid increases the potency of depigmenting agents for the treatment of melasma, actinic lentigines, and postinflammatory hypermelanosis. The basic mechanisms underlying these effects are not completely identified. Topical retinoids stimulate the cell turn-over of epidermal keratinocytes and promote a decrease in melanosome transfer and a rapid loss of melanins via epidermopoiesis. Topical retinoids are also involved in the control of cell differentiation. Retinoid-induced changes in the stratum corneum and the permeability barrier may also facilitate the penetration of depigmenting agents in the epidermis and increase their bioavailability, leading to increased depigmentation. In addition, several in vitro studies demonstrate that cis and trans-retinoic acid inhibit UV-B stimulated melanogenesis in term of tyrosinase activity and melanin synthesis. It is likely that topical retinoids modulate epidermal melanin count via a direct action on melanocytes and epidermal keratinocytes.

Treatment of melasma

Treatment of melasma involves the use of a range of topical depigmenting agents and physical therapies. Varying degrees of success have been achieved with these therapies. The Pigmentary Disorders Academy (PDA) undertook to evaluate the clinical efficacy of the different treatments of melasma in order to generate a consensus statement on its management. Clinical papers published during the past 20 years were identified through MEDLINE searches and methodology and outcome assessed according to guidelines adapted from the US Preventive Services Task Force (USPSTF). The consensus of the group was that first-line therapy for melasma should consist of effective topical therapies, mainly fixed triple combinations. Where patients have either sensitivity to the ingredients or a triple combination therapy is unavailable, other compounds with dual ingredients (hydroquinone plus glycolic acid) or single agents (4% hydroquinone, 0.1% retinoic acid, or 20% azelaic acid) may be considered as an alternative. In patients who failed to respond to therapy, options for second-line therapy include peels either alone or in combination with topical therapy. Some patients will require therapy to maintain remission status and a combination of topical therapies should be considered. Lasers should rarely be used in the treatment of melasma and, if applied, skin type should be taken into account.

A comprehensive review of the long-term and short-term treatment of melasma with a triple combination cream

Melasma is a common disorder of hyperpigmentation and generally involves areas of the face and neck. Hyperpigmentation is especially prevalent in darker complected patients and is often difficult to treat. Hydroquinone, tretinoin, and topical corticosteroids are well established monotherapeutic agents for treating melasma and hyperpigmentation; however, a stable, once-daily formulation triple combination cream containing 0.05% tretinoin, 4.0% hydroquinone, and 0.01% fluocinolone acetonide (Tri-Luma) represents the only commercially available combination of all three agents. This product is approved by the US FDA for the treatment of facial melasma. A number of publications have described the safety and efficacy of triple combination cream in over 2000 patients with melasma, some of whom were treated for >12 months. In the initial 8-week study, 29% of patients experienced complete clearing of melasma by week 8, and 77% were clear or almost clear by week 8. Similarly, good results were seen in the two long-term studies, with the clear/mild rate ranging from 78% to 84% of patients at month 6 and from 81% to 94% of patients at month 12. Adverse events were almost always mild in severity and typically occurred only at the application site. The primary concern for most physicians using corticosteroid-containing products on the face is skin atrophy. However, only two cases of skin atrophy were reported across the three published studies. Overall, the results of these extensive studies indicate that triple combination cream is efficacious in treating melasma and exhibits a safe profile with low potential for adverse events.

Functions of peroxisome proliferator-activated receptors (PPAR) in skin homeostasis

The peroxisome proliferator-activated receptors (PPAR) are ligand-activated transcription factors that belong to the nuclear hormone receptor family. Three isotypes (PPAR alpha, PPAR beta or delta, and PPAR gamma) with distinct tissue distributions and cellular functions have been found in vertebrates. All three PPAR isotypes are expressed in rodent and human skin. They were initially investigated for a possible function in the establishment of the permeability barrier in skin because of their known function in lipid metabolism in other cell types. In vitro studies using specific PPAR agonists and in vivo gene disruption approaches in mice indeed suggest an important contribution of PPAR alpha in the formation of the epidermal barrier and in sebocyte differentiation. The PPAR gamma isotype plays a role in stimulating sebocyte development and lipogenesis, but does not appear to contribute to epidermal tissue differentiation. The third isotype, PPAR beta, regulates the late stages of sebaceous cell differentiation, and is the most effective isotype in stimulating lipid production in these cells, both in rodents and in humans. In addition, PPAR beta activation has pro-differentiating effects in keratinocytes under normal and inflammatory conditions. Finally, preliminary studies also point to a potential role of PPAR in hair follicle growth and in melanocyte differentiation. By their diverse biological effects on cell proliferation and differentiation in the skin, PPAR agonists or antagonists may offer interesting opportunities for the treatment of various skin disorders characterized by inflammation, cell hyperproliferation, and aberrant differentiation.

Peroxisome Proliferator-Activated Receptors and their Ligands

Glucocorticoids have remained one of the most frequently used classes of drugs for the treatment of skin diseases since their introduction more than 50 years ago. As a result of the discovery of new members of the nuclear hormone receptor (NR) superfamily, alternative therapeutic interventions that target retinoid and vitamin D receptors have been developed. Peroxisome proliferator-activated receptors (PPARs) comprise another important NR subfamily, consisting of three different isotypes: PPARalpha, PPARdelta (PPARbeta) and PPARgamma. These NRs are activated by a variety of natural and synthetic ligands such as fatty acids, eicosanoids, and antidiabetic and antihyperlipidaemic agents. While these receptors are established as regulators of gene expression in lipid and glucose homeostasis, evidence is now accumulating that PPARs also play a crucial role in cutaneous biology. Results from in vitro and in vivo studies have indicated the involvement of PPARs in epidermal maturation, proliferation and differentiation, as well as in immune and inflammatory responses, carcinogenesis, hyperpigmentation and skin wound healing. Furthermore, treatment of psoriatic patients with PPARgamma activators (thiazolidinediones) has been shown to induce beneficial effects. However, the effects of PPAR ligands should be carefully evaluated to determine whether they are in fact mediated via PPAR-dependent mechanisms. Nonetheless, PPARs seem to have significant potential as therapeutic targets in skin inflammatory disorders.

Expression and function of peroxisome proliferator-activated receptors in human melanocytes

BACKGROUND

Peroxisome proliferator-activated receptors (PPARs) belong to the superfamily of nuclear receptors that heterodimerize with the retinoic X receptor. Agonists of PPAR have been known to play an important role in cellular responses including proliferation and differentiation. The expression and function of PPARs have not been investigated in human melanocytes, although they have been widely demonstrated in keratinocytes of the skin.

OBJECTIVES

To investigate the expression of PPARs in human melanocytes and the effects of PPAR activators on melanocyte growth and melanogenesis.

METHODS

We used immunocytochemistry and Western blot analysis to determine whether PPARs are expressed in melanocytes. To investigate further expression of PPAR subtypes, reverse transcriptase-polymerase chain reaction analysis was performed using PPAR subtype-specific oligonucleotides. The cell proliferation was measured using the Coulter counter. The effects on pigmentation were investigated with measurement of melanin contents, tyrosinase activity and its expression.

RESULTS

The mRNA of all three PPAR subtypes, PPAR-alpha, PPAR-beta/delta and PPAR-gamma, were expressed in melanocytes. Activators for PPAR-alpha (WY-14643) and PPAR-gamma (ciglitazone) inhibited proliferation of melanocytes in a dose-dependent manner, whereas bezafibrate, a preferential activator for PPAR-beta/delta, had no effect. This growth inhibition was accompanied by the morphological change of the melanocytes to an activated form with an increased number of dendrites and enlarged cell area compared with the control. The WY-14643 and ciglitazone also appeared to stimulate the melanin synthesis of melanocytes. This increase in pigmentation was due to stimulation of the tyrosinase activity without an increase in the expression of tyrosinase.

CONCLUSIONS

PPARs are expressed in human melanocytes and PPAR-alpha and PPAR-gamma activators inhibit melanocyte growth and stimulate melanogenesis.

Optimal management of recalcitrant disorders of hyperpigmentation in dark-skinned patients

Alterations in skin pigmentation may often have a dramatic expression in individuals with a dark skin complexion and can be a source of significant emotional distress in these individuals. Hyperpigmented disorders such as melanosis (melasma), post-inflammatory hyperpigmentation, drug-induced hyperpigmentation, and erythema dyschromicum perstans tend to have a prolonged course and, in many cases, are refractory to treatment, further contributing to the psychological impairment of the affected patients. Melanosis, is a common form of facial pigmentation attributable to sunlight and hormonal factors. A range of treatment modalities, such as depigmenting agents, topical retinoids, and chemical peels in conjunction with rigorous sun protection, can improve the melanosis but the condition usually recurs. Combination regimens, including frequent applications of superficial- and medium-depth chemical peels, appear to be particularly effective and well tolerated in dark-skinned patients with melanosis. Post-inflammatory hyperpigmentation is the result of excess pigment deposition following an inflammatory skin disorder. Topical tretinoin, hydroquinone, azelaic acid, kojic acid, and glycolic acid peels have been employed with variable degrees of success. Drug-induced pigmentation is a frequent cause of acquired hypermelanosis, its clinical expression depending on the triggering molecule and the underlying pathogenetic mechanism. Identifying and discontinuing the offending agent is the main approach in this condition, although, recent reports have demonstrated the efficacy of Q-switched lasers in accelerating the pigment removal. Erythema dischromicum perstans is a characteristic dermal pigmentation occurring mainly in dark-skinned individuals. Immunomodulating agents, such as clofazimine and dapsone have been shown to lighten this disorder, although, the exact mode of action is not clear.

Cutaneous diseases in Asians

Atopic dermatitis, nummular dermatitis, dyshidrosis, and melasma seem to be more common in Asians, whereas psoriasis and skin cancer are less common. In addition, there are less common skin conditions that are usually seen in Asians, including Mongolian spot, nevus of Ota, nevus of Ito, Kawasaki disease, primary cutaneous amyloidosis, Kikuchi-Fujimoto disease, and LCAI. Awareness of these less common cutaneous disorders can be helpful, especially for clinicians who work in areas with a large Asian population.

Chemical and instrumental approaches to treat hyperpigmentation

Many modalities of treatment for acquired skin hyperpigmentation are available including chemical agents or physical therapies, but none are completely satisfactory. Depigmenting compounds should act selectively on hyperactivated melanocytes, without short- or long-term side-effects, and induce a permanent removal of undesired pigment. Since 1961 hydroquinone, a tyrosinase inhibitor, has been introduced and its therapeutic efficacy demonstrated, and other whitening agents specifically acting on tyrosinase by different mechanisms have been proposed. Compounds with depigmenting activity are now numerous and the classification of molecules, based on their mechanism of action, has become difficult. Systematic studies to assess both the efficacy and the safety of such molecules are necessary. Moreover, the evidence that bleaching compounds are fairly ineffective on dermal accumulation of melanin has prompted investigations on the effectiveness of physical therapies, such as lasers. This review which describes the different approaches to obtain depigmentation, suggests a classification of whitening molecules on the basis of the mechanism by which they interfere with melanogenesis, and confirms the necessity to apply standardized protocols to evaluate depigmenting treatments.

Combined ultrapulse CO2 laser and Q-switched alexandrite laser compared with Q-switched alexandrite laser alone for refractory melasma: split-face design

BACKGROUND

: Melasma is common and can cause major psychological impact. To date, the mainstay of treatment, including various hypopigmenting agents and chemical peels, is ineffective and can cause adverse effects. Laser is a new approach and is yet to be explored for its efficacy and safety.

OBJECTIVE

: To compare combined Ultrapulse CO2 laser and Q-switched alexandrite laser (QSAL) with QSAL alone in the treatment of refractory melasma.

METHODS

: Six Thai females were treated with combined Ultrapulse CO2 laser and QSAL on one side of the face and QSAL alone on the other side. The outcome was evaluated periodically for up to 6 months using the modified Melasma Area and Severity Index score and the modified Melasma Area and Melanin Index score.

RESULTS

: The side with combination treatment had a statistically significant reduction of both scores. On the QSAL side, the score reduction was not significant. Two cases developed severe postinflammatory hyperpigmentation and were effectively treated with bleaching agents. Transient hypopigmentation and contact dermatitis were observed with the combination treatment side.

CONCLUSIONS

: Combined Ultrapulse CO2 laser and QSAL showed a better result than QSAL alone but was associated with more frequent adverse effects. Long-term follow-up and a larger number of cases are required to determine its efficacy and safety for refractory melasma.

The Combination of Glycolic Acid Peels With a Topical Regimen in the Treatment of Melasma in Dark-Skinned Patients: A Comparative Study

BACKGROUND

Melasma continues to be a difficult condition to treat, especially in dark-skinned patients, although various topical modalities including hydroquinone, tretinoin, and/or topical steroids have been used singly or in combination with variable results.

OBJECTIVE

To determine if serial glycolic acid peels provide additional improvement when combined with a time-tested topical regimen, a modification of Kligman's formula (hydroquinone 5%, tretinoin 0.05%, hydrocortisone acetate 1% in a cream base). All cases had epidermal melasma as detected by Wood's light examination.

METHODS

Forty Indian melasma patients were divided into two groups of 20 each. One group received serial glycolic acid peel combined with a topical regimen, modified Kligman's formula. The other, a control group, received only modified Kligman's formula. The results were evaluated by a clinical investigator both subjectively and with photographs taken at baseline, 12 (before the fourth peel), and 21 (3 weeks after the sixth peel) weeks. For clinical evaluation, the Melasma Area and Severity Index (MASI) was used.

RESULTS

A significant decrease in the MASI score from baseline to 21 weeks was observed in both groups (P <.001). The group receiving the glycolic acid peels showed a trend toward more rapid and greater improvement, with statistically significant results (P <.001). Only a few side effects were observed in the peel group.

CONCLUSION

This study demonstrates that serial glycolic acid peels provide an additional effect to a topical regimen which is a modification of the time-tested Kligman's regimen for treating melasma in dark-complexioned individuals if used judiciously and under supervision. It demonstrates that superficial chemical peels are beneficial in the treatment of melasma.

A comparison of adapalene gel 0.1% vs. tretinoin gel 0.025% in the treatment of acne vulgaris in China

AIM

To compare the efficacy, safety and tolerability of adapalene gel 0.1% vs. tretinoingel 0.025% in a Chinese patient population.

BACKGROUND

Although acne vulgaris is a common problem among Asians and Asian-Americans, little has been published on the specific manifestations, sequelae, and treatment-responsiveness of this disorder in Asian skin types. Since Asian skin types tend to be more highly pigmented than those of white people of European descent, many Asians share the predisposition toward postinflammatory hyperpigmentation seen in Africans, African-Americans and other dark-skinned peoples. It is generally assumed that the efficacy and safety of topical retinoids is the same in Asians as in white people. Tretinoin has been available in China for decades; adapalene became available in 1998.

METHODS

A total of 150 patients with grade II-III acne vulgaris seen at three dermatology clinics were randomized to 8 weeks of daily treatment with either adapalene gel 0.1% or tretinoin gel 0.025%. Counts of total lesions, inflammatory lesions and non-inflammatory lesions were made at baseline and again at treatment weeks 2, 4, 6 and 8. Global assessment ratings, based on percent lesion reduction from baseline were also made. Erythema, burning, pruritus, scaling and dryness were rated on a 0-3 severity scale.

RESULTS

A total of 139 patients completed the efficacy evaluation, and 144 patients completed the safety evaluation. Both adapalene and tretinoin produce dramatic reductions in total, inflammatory and non-inflammatory lesion counts, in the range of 69-74% on average. More than 70% of patients in both groups had complete clearance or marked improvement. In general, irritation was mild, but was both more common and more severe in the tretinoin group vs. the adapalene group. No systemic side effects were seen.

CONCLUSIONS

Adapalene offers comparable efficacy to tretinoin, but is less irritating. It represents a good alternative for the treatment of mild to moderate acne vulgaris in Chinese patients.

Pharmaceutical and clinical assessment of hydroquinone ointment prepared by extemporaneous nonsterile compounding

Ointments of the skin depigmentation agent hydroquinone (HQ) have been prepared by extemporaneous nonsterile compounding in Japan by imitating skin lightening creams commercially available in the U.S.A. and European Union. In our hospital, HQ ointments consisting of 5 or 10% HQ, 1.6% L(+)-ascorbic acid (AsA), 0.5% (w/w) Na2SO3, 10% (v/w) glycerin and hydrophilic ointment have been prepared. However, various problems have been observed including chromatic aberration of HQ ointments, relatively large variability of efficacy, and undesirable side effects although they were mild. Herein, the pharmaceutical and clinical properties of the HQ ointments were evaluated. HQ ointments were highly effective for treatment of various types of skin pigmentation. Chromatic aberration occurred during 3 months of storage, but this could be suppressed by storage at 4 degrees C. Chromatic aberration was independent of prescribed HQ content, and was not explained by alterations of HQ or p-benzoquinone (p-BQ) contents. Unexpectedly, removal of both antioxidants resulted in suppression of chromatic aberration, but an increase in p-BQ content. Acidification by removal of Na2SO3 only was further effective for the suppression of chromatic aberration, but with a decrease of p-BQ content except in the initial period. Chromatic aberration was due to water soluble material and insoluble material both formed by co-existence of HQ and p-BQ at a molecular ratio of 5:3 to 1:1. 1H-NMR analysis elucidated that the water soluble material was not HQ or p-BQ, and the insoluble material was a complex of HQ and p-BQ with non-covalent binding.

Application of computerized image analysis in pigmentary skin diseases

BACKGROUND

Melanocyte number and the amount of melanin pigment are related to diagnosis and treatment of pigmentary skin diseases. Various histologic methods are used, such as Fontana-Masson stain for melanin pigment or immunohistochemical stain for melanocytes. Recently, computerized image analysis has been applied to many fields to avoid interobserver bias. In this study, we applied a computerized image analysis to assess the melanin content and melanocyte density of human epidermis.

METHODS

We evaluated the skin biopsy specimens (paraffin blocks) from normal human skin (33 +/- 6.6, n = 11) and diseased skins; vitiligo (32 +/- 10.0, n = 8), melasma (35 +/- 8.6, n = 11), and lentigo senilis (40 +/- 7.2, n = 11) (mean age +/- SD). Each specimen was stained with Fontana-Masson for melanin pigments and immunohistochemical method for melanocytes. Quantitative analysis of melanin pigment and melanocyte number (density) were investigated through two methods: (1) two dermatologists measured the visual scales; and (2) computerized image analysis was used to measure melanin content indices (MCI). The data were evaluated using one-way ANOVA.

RESULTS

The visual scale of the Fontana-Masson stain was the highest for lentigo senilis (3.8 +/- 0.40), followed by melasma (2.6 +/- 0.67), normal skin (1.8 +/- 0.60) and vitiligo (0) (P < 0.05). These findings were consistent with objective measurements made by computerized image analysis. MCI values were 120.3 +/- 20.74 for lentigo senilis, 81.1 +/- 19.27 for melasma, 45.5 +/- 16.92 for normal skin, and 0.3 +/- 0.30 for vitiligo in decreasing order (P < 0.05). MC/1E (melanocyte number per 1 mm epidermis) was about two fold larger in lentigo senilis (18.1 +/- 8.92) than melasma (9.7 +/- 2.40) or normal skin (9.3 +/- 2.67) (P < 0.05). MC/1B (melanocyte number per 1 mm basal layer) was about 1.5 fold higher in lentigo senilis (13.5 +/- 4.17), compared to normal skin (9.0 +/- 3.55) (P < 0.05). Melasma showed increased melanocyte numbers compared to normal skin, but it was not statistically significant (P > 0.05).

CONCLUSION

We believe this computerized image analysis could be useful tool for diagnosis and comparison of interval changes in pigmentary diseases like melasma or lentigo senilis by quantifying melanin pigments or melanocytes in skin biopsy specimens.