Melasma: The need for tailored photoprotection to improve clinical outcomes.

BACKGROUND/PURPOSE: Melasma is a frequent photoexacerbated hyperpigmentary disorder, which can significantly impact on the quality of life. We sought to review the pathogenesis of melasma, and the role of photoprotection in the prevention and treatment of this disorder. METHODS: We conducted a narrative review of the literature. We performed literature searches with PubMed from January 1990 to December 2021 using the keywords "melasma," "pathogenesis," "ultraviolet radiation," "visible light," "photoprotection," and "sunscreens." RESULTS: The physiopathology of melasma includes a complex interaction between genetics, sex hormones, and sun exposure. Visible light, in particular high-energy visible light (HEVL), and long-wave UVA (UVA1) play a key role in melasma pathophysiology, and recent research suggests that melasma shares many features with photoaging disorders. Melasma disproportionately affects dark-skinned individuals. Some 30% to 50% of South Americans and Asians, among other ethnicities, can present with melasma. Dark-skinned patients take fewer photoprotective measures. Also, the majority of melasma patients do not adequately follow photoprotection recommendations, including the application of sunscreen. Intensive use of a broad-spectrum sunscreen can prevent melasma in high-risk individuals, can lessen melasma severity (associated or not with depigmenting agents), and can reduce relapses. CONCLUSIONS: Due to the physiopathology of melasma, sunscreens should be broad-spectrum with high sun protection factor, and provide high protection against UVA1 and VL. Sunscreens should be cosmetically acceptable and leave no white residue. Tinted sunscreens are an excellent choice, as pigments can protect from HEVL and UVA1, and may provide camouflage, but they must offer colors that match the skin tone of each patient.

Disease characteristics, determinants, and perception of use of sunscreen and sun-protective behaviors among patients of color with melasma: A cross-sectional study.

BACKGROUND: Melasma is an acquired state of hyperpigmentation that most commonly affects the face. The use of sunscreen is essential in melasma treatment. We sought to investigate patients' perspectives and behaviors toward sunscreen usage. METHODS: A cross-sectional hospital-based study targeted 418 melasma patients from May 2019 to May 2021. Data regarding socio-demographic characteristics and the knowledge, attitude, and behavior toward sunscreen and sun exposure were collected and analyzed. Furthermore, a complete clinical assessment was done. RESULTS: The mean age of the patients was 35.4 ± 8.6 years. Melasma distribution was mostly centro-facial (49.8%). The mean duration of the disease was 22.3 ± 11.6 months, with a mean Melasma Area and Severity Index (MASI) score of 18.6 ± 8.9. Only 170 patients believed that sun exposure played a role in their disease. Skin darkening was the most recognized effect of sun exposure by 92.9% of participants. 58.6% reported using sunscreen with a higher female predominance (p < .001), while males reported more broad-spectrum sunscreen usage (p < .001). The reason that was reported the most behind not using sunscreen was the high cost (94%). CONCLUSIONS: Our study showed a sound level of knowledge regarding the effects of sun exposure, and sunscreen advantages and disadvantages, with relatively inadequate translation into their attitudes and practices regarding sun-protective behaviors. The use of sunscreen among the patients was average in numbers with a higher female predominance.

Skin protective effect of guava leaves against UV-induced melanogenesis via inhibition of ORAI1 channel and tyrosinase activity.

Ultraviolet (UV) irradiation is a major environmental factor affecting photoageing, which is characterized by skin wrinkle formation and hyperpigmentation. Although many factors are involved in the photoageing process, UV irradiation is thought to play a major role in melanogenesis. Tyrosinase is the key enzyme in melanin synthesis; therefore, many whitening agents target tyrosinase through various mechanisms, such as direct interference of tyrosinase catalytic activity or inhibition of tyrosinase mRNA expression. Furthermore, the highly selective calcium channel ORAI1 has been shown to be associated with UV-induced melanogenesis. Thus, ORAI1 antagonists may have applications in the prevention of melanogenesis. Here, we aimed to identify the antimelanogenesis agents from methanolic extract of guava leaves (Psidium guajava) that can inhibit tyrosinase and ORAI1 channel. The n-butanol (47.47%±7.503% inhibition at 10 µg/mL) and hexane (57.88%±7.09% inhibition at 10 µg/mL) fractions were found to inhibit ORAI1 channel activity. In addition, both fractions showed effective tyrosinase inhibitory activity (68.3%±0.50% and 56.9%±1.53% inhibition, respectively). We also confirmed that the hexane fraction decreased the melanin content induced by UVB irradiation and the ET-1-induced melanogenesis in murine B16F10 melanoma cells. These results suggest that the leaves of P. guajava can be used to protect against direct and indirect UV-induced melanogenesis.

Undesirable Enzymatic Browning in Crustaceans: Causative Effects and Its Inhibition by Phenolic Compounds.

Undesirable enzymatic browning mediated by polyphenol oxidase (E.C. 1.14.18.1) on the surface of seafood from crustaceans have been a great concern to food processors, causing quality losses of seafood products. Seafoods especially from crustaceans are worldwide consumed due to their delicacy and nutritional value. However, black spot formation (melanosis) is the major problem occurring in crustaceans during postmortem handling and refrigerated storage induce deleterious changes in organoleptic properties and, therefore, decreases commercial value. Polyphenoloxidase (PPO), the copper-containing metalloprotein involved in oxidation of phenol to quinone is the major biochemical reaction of melanosis formation. This enzymatic mechanism causes unappealing blackening in postharvest crustaceans. To alleviate the melanosis formation in crustaceans, use of phenolic compounds from plant extract can serve as antimelanotics and appears to be a good alternative to the conventional sulfites which are associated with health-related disorders. In this review, we focuses on the unique features about the structure, distribution, and properties of PPO as well as mechanism of melanosis formation and provide a comprehensive deeper insight on the factors affecting melanosis formation and its inhibition by various antimelanotics including newly discovered plant phenolic compounds.

Near-visible light and UV photoprotection in the treatment of melasma: a double-blind randomized trial.

BACKGROUND: Melasma is an acquired hyperpigmentation on sun-exposed areas. Multiple approaches are used to treat it, but all include broad ultraviolet (UV)-spectrum sunscreens. Visible light (VL) can induce pigmentary changes similar to those caused by UV radiation on darker-skinned patients. OBJECTIVE: To assess the efficacy of sunscreen with broad-spectrum UV protection that contains iron oxide as a VL-absorbing pigment (UV-VL) compared with a regular UV-only broad-spectrum sunscreen for melasma patients exposed to intense solar conditions. METHODS: Sixty-eight patients with melasma were randomized in two groups to receive either UV-VL sunscreen or UV-only sunscreen, both with sun protection factor ≥ 50, over 8 weeks. All patients received 4% hydroquinone as a depigmenting treatment. At onset and at conclusion of the study, they were assessed by the Melasma Activity and Severity Index (MASI; a subjective scale), colorimetry (L*) and histological analysis of melanin. RESULTS: Sixty-one patients concluded the study. At 8 weeks, the UV-VL group showed 15%, 28% and 4% greater improvements than the UV-only group in MASI scores, colorimetric values and melanin assessments, respectively. CONCLUSIONS: UV-VL sunscreen enhances the depigmenting efficacy of hydroquinone compared with UV-only sunscreen in treatment of melasma. These findings suggest a role for VL in melasma pathogenesis.

Preparation of paeoniflorin-glycyrrhizic acid complex transethosome gel and its preventive and therapeutic effects on melasma.

Paeoniflorin (PF) and glycyrrhizic acid (GL) have skin beautifying effects of anti-inflammation, anti-oxidation, inhibition of melanin formation, and reduction of skin pigmentation. To improve the transdermal permeability of PF and GL in transdermal drug delivery system (TDDS) and enhance their anti-melasma efficacy, PF-GL transethosome (PF-GL-TE) was prepared by ethanol injection method, and finally gelled with carbomer-940 to form PF-GL-TE gel. Consequently, the obtained PF-GL-TE is small and uniform, with an average particle size and a PDI value of about 167.9 nm and 0.102. PF-GL-TE gel showed sustained release behavior and high transdermal permeability in vitro release and transdermal tests. Meanwhile, PF-GL-TE gel played significant preventive effects on melasma induced by progesterone injection and ultraviolet radiation B (UVB) irradiation. According to the results of H&E staining and Masson staining of rat skin, PF-GL-TE gel can alleviate the skin inflammation of and reduce the loss of collagen fibers of back skin in the melasma model rats. Compared with the PF-GL mixture gel, PF-GL-TE gel significantly attenuated the oxidative damage of liver and skin by increasing the activity of SOD and reducing the content of MDA. The results of Western blot showed that PF-GL-TE gel might down-regulate melanin-related proteins expressions of MITF/TYR/TRP1 and TRP2 to prevent and treat melasma. These findings indicate that PF-GL-TE gel is an effective TDDS for delivering PF and GL into the skin, providing a promising preparation for effective prevention and treatment of melasma.

Use of fractional laser in mixed-race patients.

The use of fractional lasers in mixed race patients has always been a challenge. Post-inflammatory hyperpigmentation or worsening of existing melasma is a risk and its presence can be unpredictable. The authors present their experience in patients with Fitzpatrick skin types IV to VI using fractional lasers. Pre- and post-laser regimens to avoid complications are presented and results are evaluated.

The treatment of melasma by silymarin cream.

BACKGROUND: Melasma is an acquired increased pigmentation of the skin characterized by symmetrical and confluent grey-brown patches usually on the areas of the face exposed to the sun. Silymarin strongly prevents photocarcinogenesis, and significantly prevented melanin production. The objectives of this study were the assessment of safety and efficacy of topical Silymain (SM) cream in a double-blind placebo controlled study for treatment of melasma patients. METHODS: Experimentally on 24 Albino rabbits were randomly divided into 4 equal groups. [A] No treatment, [B] received placebo, [C] treated with SM cream (0.1), & [D] treated by SM (0.2), were applied topically before UV sun light exposure for 30 days, assessed clinically & tissue pathology. Clinically on 96 adults diagnosed with melasma randomized to three equal groups to receive one of the tested drugs applied twice daily for 4 weeks, evaluated by the response; lesion size, melasma area and severity index score, Physician global assessment, and subjective assessment. RESULTS: The Clinical and histopathology observations were reduced significantly in SM groups. Clinically; all patients showed significant excellent pigment improvement & lesion size reduction with SM treatments from the 1st week. All patients were fully satisfied 100%. No side effects were observed. CONCLUSIONS: Silymarin showed tremendous improvement of melasma in a dose-dependent manner, and was effective in prevention of skin damage caused by U.V. sunlight. It is a safe new candidate effective treatment for melasma. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry - ACTRN12612000602820.

Preventing melasma recurrence: prescribing a maintenance regimen with an effective triple combination cream based on long-standing clinical severity.

BACKGROUND: The relapsing nature of melasma emphasizes the need to maintain efficacy achieved after acute treatment. OBJECTIVE: To compare clinical efficacy and safety of two 6-month Triple Combination (TC; containing fluocinolone acetonide, hydroquinone and tretinoin) maintenance regimens in subjects with moderate to severe melasma, after daily treatment up to 8 weeks. METHODS: This randomized, investigator-blinded, controlled study had a maintenance phase of 6 months. Sixteen centres in Brazil and Mexico enrolled 242 subjects 18 years or older attaining no or mild melasma after 8 weeks of daily TC applications. Subjects were randomized to receive TC in a twice weekly or tapering regimen [3/week (1st month), 2/week (2nd month), 1/week (4th month)]. Efficacy and safety measurements included median time to relapse and relapse-free rate, Global Severity Score, Melasma Area and Severity Index score (MASI), subject's assessment, quality of life questionnaire (MelasQol), and adverse events. RESULTS: The majority (78.8%) had no or mild melasma (GSS ≤ 1) at week 8 and entered maintenance phase. After 6 months, 53% of patients remained relapse-free with improved quality of life, and time to relapse was similar between groups (about 190 days). Melasma severity at study entry, not maintenance baseline, influenced relapse rate. The twice weekly regimen tended to show better effectiveness in postponing relapse in severe melasma. Both regimens were safe. CONCLUSIONS: After resolution of melasma with TC, maintenance therapy over 6 months was successful in preventing relapse in over half of the patients who entered maintenance phase. Prescribing medicines should be adapted to patients based on melasma severity.

Chloasma--the mask of pregnancy.

Chloasma is a required hypermelanosis of sun-exposed areas occurred during pregnancy and it can affect 50-70% of pregnant women. It presents as symmetric hyperpigmented macules, which can confluent or punctuate. The most common locations are the cheeks, the upper lip, the chin and the forehead. The exact mechanism by which pregnancy affects the process of melanogenesis is unknown. Estrogen, progesterone, and melanocyte-stimulating hormone (MSH) levels are normally increased during the third trimester of pregnancy. However, nulliparous patients with chloasma have no increased levels of estrogen or MSH. In addition, the occurrence of melasma with estrogen- and progesterone-containing oral contraceptive pills has been reported. The observation that postmenopausal woman who are given progesterone develop melasma, while those who are given only estrogen do not, implicates progesterone as playing a critical role in the development of melasma. UV-B, UV-A, and visible light are all capable of stimulating melanogenesis. The condition is self-limited; however spontaneous resolution is time-consuming and may take months to resolve normal pigmentation. Therefore, it is worthwhile to prevent the onset of chloasma, by strict photoprotection. Prudent measures to avoid sun exposure include hats and other forms of shade combined with the application of a broad-spectrum sunscreen at least daily. Sunscreens containing physical blockers, such as titanium dioxide and zinc oxide, are preferred over chemical blockers because of their broader protection. Chloasma can be difficult to treat. Quick fixes with destructive modalities (eg, cryotherapy, medium-depth chemical peels, lasers) yield unpredictable results and are associated with a number of potential adverse effects. The mainstay of treatment remains topical depigmenting agents. Hydroquinone (HQ) is most commonly used.

Melasma, a photoaging disorder.

Melasma is a common hyperpigmentary disorder. The impact on the quality of life of affected individuals is well demonstrated, demanding new therapeutic strategies. However, the treatment of melasma remains highly challenging. Melasma is often considered as the main consequence of female hormone stimulation on a predisposed genetic background. Although these two factors do contribute to this acquired pigmentary disorder, the last decade has revealed several other key players and brought new pieces to the complex puzzle of the pathophysiology of melasma. Here, we summarize the latest evidence on the pathophysiology of melasma, and we suggest that melasma might be a photoaging skin disorder affecting genetically predisposed individuals. Such data must be taken into consideration by clinicians as they could have a profound impact on the treatment and the prevention of melasma.

The treatment of melasma: a review of clinical trials.

Melasma is an irregular brown or grayish-brown facial hypermelanosis, often affecting women, especially those living in areas of intense UV radiation. The precise cause of melasma remains unknown; however, there are many possible contributing factors. Because of its dermal component and tendency to relapse, melasma is often difficult to treat. The use of broad-spectrum (UVA + UVB) sunscreen is important, as is topical hydroquinone, the most common treatment for melasma. Other lightening agents include retinoic acid (tretinoin) and azelaic acid. Combination therapies such as hydroquinone, tretinoin, and corticosteroids have been used in the treatment of melasma, and are thought to increase efficacy as compared with monotherapy. Kojic acid, isopropylcatechol, N-acetyl-4-cysteaminylphenol, and flavonoid extracts are other compounds that have been investigated for their ability to produce hypopigmentation, but their efficacy, safety, or trial design indicates that the interventions would need further study before they could be recommended. Chemical peels, laser treatments, and intense pulsed light therapy are additional therapeutic modalities that have been used to treat melasma.

Sun protection strength of a hydroquinone 4%/retinol 0.3% preparation containing sunscreens.

BACKGROUND: Dyschromias are common and significantly impact patients' quality of life. Formulas containing hydroquinone 4% are effective in these conditions. Since exposure to ultraviolet radiation (UVR) can worsen disease and complicate treatment, the incorporation of sunscreens can avert this problem. METHODS: We tested the sun protection factor of a hydroquinone formulation (Lustra-Ultra, TaroPharma, Hawthorne, NY) containing avobenzone 3%, and octinoxate 7.5% according to the FDA Sunscreen Monograph on 20 volunteer subjects. We also determined the UVR absorbance spectrum of the preparation. RESULTS: The mean sun protection factor (SPF) of 21.7 satisfied labeling requirements for SPF 20. The formulation exhibited strongest photoprotection near the wavelengths of peak sun burning effectiveness in the UVB region and maintains significant UVR absorbance through the entire UVA region. CONCLUSIONS: Avobenzone 3% and octinoxate 7.5% provide broad spectrum UV protection. Incorporating these sunscreens into a hydroquinone preparation simplifies the treatment regimen while providing significant photoprotection for patients being treated for dyschromia.

Topical treatments for melasma and postinflammatory hyperpigmentation.

Hyperpigmentation disorders of the skin are common and can be the source of significant psychosocial distress for patients. The most common of these disorders are melasma and postinflammatory hyperpigmentation. Sunscreen use and minimizing sun exposure are crucial in all cases. Topical applications are the mainstay of treatment and include phenols, retinoids, corticosteroids, and their combinations.

Melanocytic Nevi in Children: A Review.

Common moles on the skin, known scientifically as melanocytic nevi, are seen frequently in the pediatric population. They are broadly grouped into two groups: congenital (generally present at birth or in infancy) or acquired. Congenital melanocytic nevi (CMN) are classified based on size and morphologic features. Neurocutaneous melanosis and melanoma represent two important complications, with overall risk affected by nevus size, location, appearance, and number of satellite lesions. Regular lifelong skin surveillance is required for high-risk CMN. Acquired melanocytic nevi (AMN) tend to appear in childhood and increase in number through adolescence. Risk factors for melanoma in children with moles include having more than 50 AMN, clinically atypical AMN, family history of melanoma, excessive ultraviolet light exposure, lightly pigmented skin, and immunosuppression. Children with risk factors should be monitored regularly. The periodic health examination presents an opportunity to perform total body skin examination to screen for concerning lesions and to provide anticipatory guidance about sun protection. [Pediatr Ann. 2016;45(8):e293-e298.].

Role of sulfites and 4-hexylresorcinol in microbial growth and melanosis prevention of deepwater pink shrimp (Parapenaeus longirostris) using a controlled atmosphere.

A controlled atmosphere containing 48% CO2 and 7% O2 was used in association with refrigeration for storage of deepwater pink shrimp (Parapenaeus longirostris). Shrimp were treated with two different concentrations of sodium metabisulfite or 4-hexylresorcinol and subjected to the controlled atmosphere immediately after capture onboard ship or on arrival in port. Total volatile basic nitrogen, total viable counts, enterobacteria, lactic acid bacteria, and luminescent bacteria were determined, and black spot progression was evaluated. The combined effect of controlled atmosphere and melanosis inhibitors was used to delay black spot development as compared to the shrimp stored in ice alone. Storage under the controlled atmosphere without ice limited microbiological quality, namely, total viable counts, but enterobacterial growth was lower.

[Sunscreens: use in pregnant women at Casablanca]. / Photoprotecteurs externes. Utilisation chez la femme enceinte à Casablanca.

BACKGROUND: Photoprotection with sunscreens is recommended in hyperpigmentation, particularly in pregnancy-related form. The aim of this study was to evaluate the use of sunscreens in pregnant women and to determine whether melasma was correlated to sunscreen use. PATIENTS AND METHODS: Four hundred and fifteen pregnant women were surveyed by a standardized questionnaire on the presence of melasma and their use of sunscreens. The study took place in Casablanca, Morocco, in two public maternity hospitals and two private gynaecologic centres, from April 1999 to July 1999, during antenatal consultations. RESULTS: The mean age of the 415 pregnant women was 29 +/- 6 years. One hundred and fifty-one women (37 p. 100) had a melasma and 72 (17 p. 100) used a sunscreen at their inclusion in the study. Women with melasma used sunscreens in 18.8 p. 100 and the others in 16.6 p. 100. Users of sunscreens differed from non-users in their higher level of instruction, professional activity, presentation in private practice and of urban origin. DISCUSSION: This study showed a low incidence of sunscreen use in our population of pregnant women. Melasma wasn't a reason for using sunscreens. However, access to medical information, especially to photoprotection advice, and the financial possibility of buying the product led to larger use of sunscreens. Up to now no study has confirmed that sunscreens can prevent melasma in dark phototype women with pregnancy. It would therefore be difficult to recommend them to pregnant women.