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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., Competing Interests: Declaration of Competing Interest The authors declare that there are no conflicts of interest., (Copyright © 2023. Published by Elsevier B.V.)

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., (© 2022 The Authors. Photodermatology, Photoimmunology & Photomedicine published by John Wiley & Sons Ltd.)

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., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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.]., (Copyright 2016, SLACK Incorporated.)

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.

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., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Cancer chemotherapy is associated with serious side effects, including temporary hair loss and impairment of pigmentation. We suspect that ectopic melanin deposition occurring due to chemotherapy may add to these effects worsening the already unpleasant symptoms. We associated the ectopic occurrence of follicular melanin after chemotherapy with splenic melanosis - an interesting example of extradermal melanin localization - and we expected an increase in splenic melanin deposition after chemotherapy. Using the C57BL/6 murine model of synchronized hair cycle induced by depilation, we visualized splenic melanin by means of several histological and histochemical protocols of staining: hematoxylin and eosin, May-Grünwald-Giemsa and Fontana-Masson. Unexpectedly, the splenic deposition of melanin decreased due to application of cyclophosphamide (i.p. 120 mg/ kg body weight on day 9 post depilation). The drop was abrupt and lasted for at least 5 days (day 13-18 post depilation), as compared with normal hair cycle. Moreover, in mice with normal, depilation-induced hair cycle we observed a similar drop shortly before entering catagen (day 15 post depilation), followed by a slow and partial increase in splenic melanization up to day 27 post depilation in both groups. We conclude that cyclophosphamide negatively affects splenic melanization and/or extradermal transfer of ectopic melanin from the dystrophic hair follicles, but the most powerful down-regulator of splenic melanosis is normal and dystrophic catagen - the phase of hair follicle involution and re-modelling.

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.

Purpose: To evaluate habits of sun exposure and sun protection of pregnant women in a public hospital, to assess orientation about photo protection during the prenatal care, and to detect the presence of melasma and its impact on their quality of life., Methods: A descriptive cross sectional study conducted among women of 18 years old and older, after delivery, who participated in a program of prenatal care in the South Region of Brazil. The sample was non-probabilistic by convenience. Data collection occurred from July to August 2011 through direct interview using a structured questionnaire to obtain personal information and photo protection habits during pregnancy, skin assessment and photographic record of lesions through informed consent. The skin was classified per Fitzpatrick's phototypes and the melasma was diagnosed clinically. In the patients with melasma, the MELASQoL-PB version was applied. The analysis was performed using Statistica, version 8.0, and the significance level of p<0.05., Results: In the sample (109 mothers) predominated white women (60.6% phototype III), young (average age 24.4 years SD=6.1) and housewives (59.6%). The majority (80%) stayed exposed to sunlight for 1-2 hours per day between 10 am and 3 pm, and from those (72%) did not apply any photoprotection due to lack of sunscreen habit. Other physical means of sun protection were used by 15% of these patients. Information during prenatal care about the risks of sun exposure was reported by 34% of the mothers interviewed. There was a trend toward a significant association between prenatal guidance and daily use of sunscreen (p=0.088). About 20% of mothers had melasma. The average score MELASQol-PB (25) showed a negative impact on quality of life of these patients., Conclusion: In these women, sun exposure occurred at inappropriate times, without proper guidance and without the use of an effective sunscreen. The mothers with melasma complained about the appearance of their skin, frustration and embarrassment.

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., (© 2011 The Authors. Journal of the European Academy of Dermatology and Venereology © 2011 European Academy of Dermatology and Venereology.)

Background: The use of oral estrogen-progestogen contraceptives may cause melasma, an epidermal hyperpigmentation in sun-exposed areas of the face. It is assumed that elevated estrogen levels lead to the activation of melanocytes, while the role of the gestagen component of contraceptives in pigmentation remains unclear and may vary between the different progestogens. In this study, we analyzed the distinct effects of progesterone and chlormadinone acetate (CMA) on melanocytes in comparison with estrogen., Study Design: Human melanocytes were exposed to different concentrations of 17beta-estradiol and progestogens and analyzed for proliferation by a fluorometric cell viability assay and for pigmentation by a (3)H-labeled tyrosine assay. Subgroups of cells were additionally irradiated with UVA or UVB., Results: Proliferation of melanocytes was induced by 17beta-estradiol (0.1 and 1 nM) in approximately half of the experiments, while progesterone (100 nM) and CMA (100 nM) reduced the proliferation rate by 38% and 27%, respectively. The pigmentation activity was slightly stimulated by 17beta-estradiol, whereas progestogens had no effect on the tyrosinase activity., Conclusions: Our data suggest that progesterone and CMA can inhibit proliferation of human melanocytes, which counteracts the stimulatory effects of estrogen. This may be of relevance for the choice of progestogen in oral contraceptives to prevent the development of melasma.

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.

The effect of pretreatment with pyrophosphate and 4-hexylresorcinol in combination with modified atmosphere packaging (MAP) (80% CO(2), 10% O(2), 10% N(2), or 80% CO(2), 20% N(2)) on the quality of white shrimp during storage at 4 degrees C was investigated. Shrimp pretreated with 2% pyrophosphate and 0.25% 4-hexylresorcinol and stored under MAP showed the lower microbiological and chemical deteriorations as evidenced by delayed microbial growth as well as lower trimethylamine (TMA) and total volatile base nitrogen (TVB) production (P < 0.05). Additionally, the growth of coliforms was inhibited effectively. White shrimp pretreated with 4-hexylresorcinol had the lower melanosis throughout the storage compared with those without treatment (P < 0.05). This was associated with the lowered polyphenol oxidase (PPO) activity in shrimp treated with 4-hexylresorcinol. Therefore, the effective retardation of microbiological and chemical deterioration of white shrimp stored under MAP with the decrease in melanosis could be achieved by pretreatment of the shrimp with pyrophosphate and 4-hexylresorcinol. Furthermore, decapitation could be another means to lower the microbial load and melanosis in white shrimp, particularly those stored under MAP.

This was a cross-sectional study under taken to explore the socioeconomic perspective of the arsenicosis problem, carried out in arsenic contaminated Upazillas where at least 100 arsenicosis patients had been identified. Two of the Upazillas with significant arsenic mitigation intervention and three of the Upazillas with limited interventions were selected for the study. Seven hundred fifty respondents were included in the study from 25 villages of the 5 Upazillas. Arsenicosis became a serious problem for the affected communities. Majority (71.31%) of respondents obtained their drinking water from tubewells, almost one third (29%) of the respondents still knowingly using arsenic contaminated water. Primary reason identified for this practice was distance of safe water source. Majority (58.6%) of the respondents said to face economic and 17.9% said to face social problem of varied range. Patients of lower income group were particularly more likely to face economic problems (P< .001) as well as social problem (P< .01). About half (50.7%) of the arsenicosis patients faced difficulty whilst receiving treatment, particularly female patients were more likely to face problem than male (P< .05). Several concerns also were surfaced regarding the heath care service provider particularly to the women patients, some of which are: long waiting time for receiving treatment (15%), discrimination in service delivery (10.7%) and inadequate separate facility for female patients (14.3%). Moreover the issues of financial burden raised by the respondents seem to have emerged as significant in terms of health care access. Access to Health service was particularly difficult for poor patients, as they often had to face problems associated with accessing service like, non availability of medicines in the hospitals (50.7%), traveling long distance (26.7%), purchasing medicine in most cases (32.4%) etc. Their dissatisfaction was compounded by negligent behavior of health care staff and nature of treatment provided. Furthermore length of time needed for reversal of symptoms led to loosing faith on efficacy of treatment, which cascades to negligence of patient's part in seeking health care. Women are less likely to get treatment for arsenicosis than men (P< .01). As there appear to be specific difficulties for women particularly for poor women in accessing health care, social and cultural values make it difficult for them to attend to their own health needs and to travel to service providers. Study findings suggest that a significant proportion (79.9%) of arsenicosis patient was found to access alternative health care. This includes; Homeopath, village doctors, Kabiraj and local pharmacists. Respondents in high intervention Upazillas were significantly more likely to get treatment (P< .05), to face fewer problems and to be satisfied with the facility (P< .001). Provision of safe water options, periodic screening of water source for arsenic, availability of trained doctor, regular availability of medicine, doorstep treatment, follow up on severe patients were the suggestions came from community for improvement.

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.

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.

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.

The number of melanocytic nevi is the most important risk factor for cutaneous melanoma. This 1998 cross-sectional study of 1,812 children aged 2-7 years from 78 day-care centers in Germany analyzed the protective effect of sunscreen and clothing on the number of melanocytic nevi. Total body nevi were counted, and pigmentary features were assessed. Parents underwent a standardized interview concerning their children's sun exposure and sun-protective behavior. Almost 95% of the children had used sunscreen previously. Children who used sunscreen and wore more clothing spent significantly longer periods on holidays in sunny climates (p < 0.001 and p = 0.006, respectively) and had a higher outdoor activity score at home (p < 0.001 and p = 0.012, respectively). Multivariate analysis adjusted for confounders showed no significant protective effects of applying sunscreen. Examination of the potential protective effect of clothing revealed an inverse dose-response correlation between the number of clothes worn at the beach or outdoor swimming pool and the number of melanocytic nevi (p < 0.001, adjusted for confounding). Randomized controlled trials are needed to confirm these results. Meanwhile, public education should aim to protect children primarily by sun avoidance and protective clothing, while sunscreen should also be used.

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.

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.

Studies were performed on the efficacy, residues and in vitro enterocyte toxicity of 4-hexylresorcinol (4-HR), which could be utilized as an inhibitor of shrimp melanosis (black spot). Mediterranean sea shrimp (Parapaeneus longirostris) were treated with solutions of 4-HR in sea-water, at three different concentrations, 25, 50 or 100 mg/kg of shrimp, to test its antioxidative property. As a comparison a group of shrimp was treated with sodium metabisulphite (1 g/kg), while another group was left untreated. 4-HR showed a marked ability to inhibit or slow down melanosis (black spot) in shrimp; the most effective concentration was 100 mg/kg within an optimum period of 7 days but with effects up to the tenth day. During the first 5 days, 4-HR residues in the edible part of the shrimp showed a fast decrease in all three groups, going from initial average values of 20 mg/kg at 0 time, to 0.9 in the group treated at 25 mg/kg; from 42 to 1.8 mg/kg in the group at 50 mg/kg and from 85 to 1.9 mg/kg in the group at 100 mg/kg. In vitro studies on enterocyte-like Caco-2 cells did not indicate any cytotoxic effect up to a concentration of 50 micrograms/ml. Moreover, no inhibition of protein synthesis was observed, which lends further support to the absence of significant damage to the intestinal mucosa induced by 4-HR. The available database on 4-HR pharmacology and toxicology is inadequate to determine even a provisional ADI. There is negative evidence of carcinogenesis and no significant untoward effects were observed in humans when it was used as an anthelmintic. However, it is not possible to determine a NOEL for non-genotoxic effects. 4-HR could become an interesting alternative to the use of sulphites to prevent black spot. However, a more complete database is needed to achieve a regulatory evaluation.

Intrinsic (chronological) skin ageing is characterized by atrophy of the skin with loss of elasticity and slowed metabolic activity. The superposition of environmental damage, particularly exposure to ultraviolet radiation (photodamage), on the intrinsic ageing process results, at least initially, in a hypertrophic repair response, with a thickened epidermis and increased melanogenesis. Even more striking changes occur in the dermis: massive elastosis (deposition of abnormal elastic fibres), collagen degeneration, and twisted, dilated microvasculature. Regular use of a sunscreen alone appears to allow some repair as well as protection from further photodamage. Topical tretinoin has been shown to partially reverse the clinical and histological changes induced by the combination of sunlight exposure and chronological ageing. A formulation of tretinoin in an emollient cream (Retinova, Renova), developed specifically for the treatment of photodamaged skin, has been extensively investigated in multicentre, double-blind trials and has been shown to produce significant improvement within 4-6 months of daily use, compared with vehicle alone, as part of a regimen including sun protection and moisturizer use. Histological changes in the epidermis and dermis noted after 12 months suggest tretinoin repairs photodamage by reconstitution of the rete pegs, repair of keratinocyte ultrastructural damage, more even distribution of melanocytes and melanin pigment, deposition of new papillary dermal collagen, and improvements in vasculature. Alpha-hydroxy acids (AHAs) have also been widely used for therapy of photodamaged skin, and these compounds have been reported to normalize hyperkeratinization and increase viable epidermal thickness and dermal glycosaminoglycans content. The single randomized controlled study now available appears to substantiate AHA efficacy and safety. In summary, recent work has substantially elucidated the ageing processes that affect the skin and has demonstrated that many of the unwanted changes can be improved by topical therapy.

Since the introduction of sodium metabisulfite as a food preservative, it has been associated with several idiosyncratic reactions (eg, bronchospasm, oculonasal symptoms, and urticaria/angioedema) in sulfite-sensitive individuals. The pathogenic mechanism of these reactions is not yet understood. We report the case of two crewmen on a shrimp trawler who were found dead in the ship's hold. Their deaths had occurred while they were applying dry sodium metabisulfite, referred to as "shrimp dip" in the shrimping industry. Postmortem examinations showed diffuse pulmonary edema consistent with death secondary to asphyxia. Associated findings were visceral congestion. Although it is possible to measure death from sodium metabisulfite with available records, its potential morbidity cannot be estimated. It is known that sodium metabisulfite can react with acids and water, releasing toxic sulfur dioxide (SO2) gas. In addition, SO2 gas reacts with respiratory tissue forming sulfureous acid, and inducing a pulmonary reaction causing hypoxemia. Furthermore, sodium metabisulfite, compared with sodium bisulfite, has a much greater propensity to release SO2 gas. We conclude that there is a need for improved education regarding the potential side effects of sodium metabisulfite, thus eliminating needless occupational morbidity and mortality.

4-Hexylresorcinol (C12H18O2) is proposed for use as a processing aid for prevention of melanosis ("black spot") in shrimp and as an alternative to the currently approved sulfites. A safety evaluation was conducted to affirm, based upon scientific procedures, the generally recognized as safe ("GRAS") status of 4-hexylresorcinol for proposed use. The GRAS safety evaluation compiled, reviewed, and analyzed data on the following areas: chemical identity, analytical methodology, historical and proposed uses, functionality, and safety. The publicly available safety data on 4-hexylresorcinol cover a broad range of potential toxicity concerns including acute and subacute toxicity, subchronic toxicity, carcinogenicity, mutagenicity, and allergenicity. These studies, along with the aforementioned data, demonstrate that 4-hexylresorcinol presents no risk of toxicity at the levels proposed for treatment of shrimp, and the use of 4-hexylresorcinol as a processing aid to prevent melanosis in shrimp is GRAS.

Prior to the late 1970s, cosmetic dermatitis was quite common in Japan. Once sensitizers were established, in cosmetics, soaps, shampoos, and other commonly used substances, effective treatment was only possible if the cycle of recrudescence could be broken. The Allergen Controlled System accomplished this by preventing contact with the main contact sensitizers. Although the number of cases of pigmented cosmetic dermatitis has declined because of restrictions on the use of several major sensitizers, the Allergen Controlled System remains an effective treatment for the cases that still occur.

65 pregnant women distributed in two groups, by a double-blind method received a placebo or a sunscreen cream (Pabafil SPF 10, with absorption range from 290 to 360 nm) for daily use on face during the second quarter of their pregnancy in summer time. In 30 patients "with optimum fulfillment" in the products application (16 with placebo and 14 with sunscreen cream) the melasma appearances were significantly lower in those with sunscreen application. In subgroups of the total number of pregnant women, with similar proportion of patients with placebo and sunscreen, the melasma appearances were significantly lower in skin types I-II, and in those that used cosmetics (versus those that did not). No differences were observed in subgroups by age, parity, and with or without history of previous melasma.