Skin Barrier Function and Its Relationship With IL-17, IL-33, and Filaggrin in Malar Melasma.

BACKGROUND: The pathogenesis of melasma remains unclear. Interleukin (IL)-17, a proinflammatory mediator, disturbs barrier function. Filaggrin (FLG) is a protein involved in epidermal barrier homeostasis and may be affected by IL-17 and IL-33. OBJECTIVE: To evaluate epidermal barrier function in malar melasma and its association with the expression of FLG, IL-17, and IL-33. METHODS: Twenty patients with malar melasma were included in this study. Colorimetric and transepidermal water loss (TEWL) was measured in lesional and adjacent unaffected skin at baseline and 30 minutes after barrier disruption using the tape-stripping test. Biopsies from melasma and perilesional skin were performed to evaluate the presence of FLG by immunohistochemistry, and profilaggrin, IL-17, and IL-33 expression were analyzed by reverse transcription-qualitative polymerase chain reaction. RESULTS: After the stripping test, the erythema and TEWL values were higher in the melasma than in the unaffected skin ( P = 0.01). Thirty minutes later, TEWL diminished, but it remained higher than in the perilesional skin. Profilaggrin increased as TEWL gradually decreased (R = -0.68, P = 0.04). FLG and IL-17 were higher in the melasma than in the perilesional skin ( P = 0.003). IL-17 and profilaggrin expression were positively associated (R = 0.60, P = 0.04). IL-33 expression was higher in the adjacent normal skin than in the melasma ( P = 0.01). CONCLUSION: This study found subclinical inflammation in the skin adjacent to the melasma, dysfunction of the epidermal barrier in lesions associated with chronic inflammation, and an abnormal differentiation process promoting an increase in FLG. These findings highlight the need to preserve the integrity of the facial stratum corneum in these patients.

Factors associated with dermatoporosis in a sample of geriatric patients in Mexico.

INTRODUCTION: Dermatoporosis is a chronic cutaneous fragility syndrome, characterized by skin atrophy, purpura and pseudo-cicatrices. OBJECTIVE: To determine factors associated with dermatoporosis in a sample of subjects aged ≥ 60 years. METHODS: Observational, cross-sectional, descriptive, analytical study of subjects aged ≥ 60 years who underwent history taking, physical examination and application of a self-administered dermatoporosis diagnostic questionnaire. To determine the associated factors, a multivariate logistic regression analysis was used. RESULTS: In 315 evaluated subjects, the prevalence of dermatoporosis was 29%; 70% were females. Associated risk factors were age > 75 years (p = 0.001), prolonged sun exposure (p = 0.002), use of anticoagulants/antiplatelet medications (p = 0.004), oral steroids (p = 0.03) and chronic kidney disease (p = 0.03), as well as maternal age > 40 years at last pregnancy (p = 0.02), breastfeeding for > 7 months per pregnancy and > 18 cumulative months (p = 0.01). Age < 20 years at first pregnancy and menopause after 45 years were related to dermatoporosis absence. The correlation between self-assessment and clinical diagnosis was considerably high (0.95, p < 0.001). CONCLUSIONS: The risk factors associated with dermatoporosis were similar to those previously reported.

INTRODUCCIÓN: La dermatoporosis es un síndrome crónico de fragilidad cutánea, caracterizado por atrofia, púrpura y pseudocicatrices en piel. OBJETIVO: Determinar los factores asociados a dermatoporosis en una muestra de sujetos ≥ 60 años. MÉTODOS: Estudio observacional, transversal, descriptivo y analítico de sujetos ≥ 60 años a quienes se realizó historia clínica, exploración física y aplicación de un autocuestionario diagnóstico de dermatoporosis. Para determinar los factores asociados se realizó análisis de regresión logística multivariado. RESULTADOS: En 315 sujetos, la prevalencia de dermatoporosis fue de 29 %; 70 % fue del sexo femenino. Los factores asociados fueron edad > 75 años (p = 0.001), exposición solar prolongada (p = 0.002), ingesta de anticoagulantes/antiplaquetarios (p = 0.004), esteroides orales (p = 0.03) y enfermedad renal crónica (p = 0.03); así como, edad materna > 40 años en el último parto (p = 0.02), lactancia > 7 meses por embarazo y lactancia acumulada > 18 meses (p = 0.01). Se relacionaron con su ausencia, edad < 20 años en el primer embarazo y menopausia después de los 45 años. La correlación entre la autovaloración y el diagnóstico clínico fue muy alta (0.95, p < 0.001). ­. CONCLUSIONES: Los factores de riesgo asociados a dermatoporosis fueron similares a los previamente reportados.

Factores asociados a dermatoporosis en una muestra de pacientes geriátricos en México / Factors associated with dermatoporosis in a sample of geriatric patients in Mexico

Resumen Introducción: La dermatoporosis es un síndrome crónico de fragilidad cutánea, caracterizado por atrofia, púrpura y pseudocicatrices en piel. Objetivo: Determinar los factores asociados a dermatoporosis en una muestra de sujetos ≥ 60 años. Métodos: Estudio observacional, transversal, descriptivo y analítico de sujetos ≥ 60 años a quienes se realizó historia clínica, exploración física y aplicación de un autocuestionario diagnóstico de dermatoporosis. Para determinar los factores asociados se realizó análisis de regresión logística multivariado. Resultados: En 315 sujetos, la prevalencia de dermatoporosis fue de 29 %; 70 % fue del sexo femenino. Los factores asociados fueron edad > 75 años (p = 0.001), exposición solar prolongada (p = 0.002), ingesta de anticoagulantes/antiplaquetarios (p = 0.004), esteroides orales (p = 0.03) y enfermedad renal crónica (p = 0.03); así como, edad materna > 40 años en el último parto (p = 0.02), lactancia > 7 meses por embarazo y lactancia acumulada > 18 meses (p = 0.01). Se relacionaron con su ausencia, edad < 20 años en el primer embarazo y menopausia después de los 45 años. La correlación entre la autovaloración y el diagnóstico clínico fue muy alta (0.95, p < 0.001). Conclusiones: Los factores de riesgo asociados a dermatoporosis fueron similares a los previamente reportados.

Abstract Introduction: Dermatoporosis is a chronic cutaneous fragility syndrome, characterized by skin atrophy, purpura and pseudo-cicatrices. Objective: To determine factors associated with dermatoporosis in a sample of subjects aged ≥ 60 years. Methods: Observational, cross-sectional, descriptive, analytical study of subjects aged ≥ 60 years who underwent history taking, physical examination and application of a self-administered dermatoporosis diagnostic questionnaire. To determine the associated factors, a multivariate logistic regression analysis was used. Results: In 315 evaluated subjects, the prevalence of dermatoporosis was 29%; 70% were females. Associated risk factors were age > 75 years (p = 0.001), prolonged sun exposure (p = 0.002), use of anticoagulants/antiplatelet medications (p = 0.004), oral steroids (p = 0.03) and chronic kidney disease (p = 0.03); as well maternal age > 40 years at last pregnancy (p = 0.02), breastfeeding for > 7 months per pregnancy and > 18 cumulative months (p = 0.01). Age < 20 years at first pregnancy and menopause after 45 years were related to dermatoporosis absence. The correlation between self-assessment and clinical diagnosis was considerably high (0.95, p < 0.001). Conclusions: The risk factors associated with dermatoporosis were similar to those previously reported.

Atrazine modifies markers of melanocyte maturation and apoptosis in primary skin cultures.

Atrazine (ATZ) is part of a group of herbicides called triazines. ATZ is widely used in agricultural areas of Mexico, commonly used for the selective control of weeds in corn and sorghum crops. The exposure to ATZ can have serious human health effects since its use was associated with the development of cutaneous melanoma in an epidemiological study. The aim of this study was to evaluate the expression of maturation and apoptotic markers in primary skin cultures exposed to ATZ. The primary skin cultures were exposed to 0.1, and 10 µM ATZ with or without ultraviolet (UV) radiation and the expression of maturation and apoptotic markers were evaluated by RT-qPCR. We observed a significant increase in all the melanocyte maturation markers in cells exposed to ATZ with or without UV, with SOX-9 and FAK (melanoblast markers) being the highest. Also, the expression of BCL-2 (anti-apoptotic marker) was the most increased gene in cells exposed to ATZ with or without UV. Low concentrations of ATZ and UV radiation induce genetic changes associated with the development of immature melanocytes and activate mechanisms associated with the inhibition of apoptosis characteristics of malignant cell transformation, which will allow proposing new therapeutic targets and generating new restrictions or care in farmers exposed to pesticides such as the ATZ.

Study of the cytotoxic and irritant effects of skin cleansing soaps.

BACKGROUND: The use of soap for skin cleansing is common among the population. However, it is possible that it causes damage to skin cells and disrupts the skin barrier. OBJECTIVE: To determine the cytotoxic effect of soaps on in vitro-cultured keratinocytes and to correlate it with clinical irritation. METHOD: A survey was conducted to find out the most widely used commercial soaps and their number. Subsequently, their cytotoxicity was evaluated in human keratinocyte cultures using the resazurin assay. The soaps with the highest and lowest cytotoxicity were applied to the skin of healthy volunteers to assess their effect on the skin barrier using colorimetry and transepidermal water loss (TEWL) assays. RESULTS: Of the analyzed soaps, 37 % were shown to be toxic to keratinocytes in vitro. The soap with the highest toxicity induced the highest rate of erythema and TEWL, in comparison with the least toxic soap and the vehicle used as the control solution. CONCLUSION: Soaps marketed for skin cleansing can contain chemical ingredients that damage human keratinocytes and cause skin barrier subclinical irritation. Their use can worsen preexisting dermatoses, generate xerotic or irritant contact dermatitis, and cause atrophy and dermatoporosis.

INTRODUCCIÓN: El jabón para el aseo cutáneo es de empleo común entre la población, sin embargo, es posible que cause daño a las células de la piel y modifique la barrera cutánea. OBJETIVO: Determinar el efecto citotóxico de los jabones en queratinocitos cultivados in vitro y correlacionarlo con la irritación clínica. MÉTODO: Se realizó una encuesta para conocer los jabones comerciales más utilizados y su cantidad; posteriormente, se evaluó su citotoxicidad en cultivos de queratinocitos humanos mediante el método de resazurina. Los jabones con mayor y menor citotoxicidad se aplicaron en piel de voluntarios sanos para evaluar su efecto en la barrera cutánea mediante ensayos de colorimetría y pérdida transepidérmica de agua. RESULTADOS: De los jabones analizados, 37 % demostró ser tóxico para los queratinocitos in vitro. El jabón con mayor toxicidad indujo el mayor índice de eritema y pérdida transepidérmica de agua, en comparación con el jabón menos tóxico y el vehículo empleado como solución control. CONCLUSIÓN: Los jabones comercializados para el aseo cutáneo pueden incluir ingredientes químicos que dañan los queratinocitos humanos y causan irritación subclínica de la barrera cutánea. Su utilización puede agravar dermatosis preexistentes, generar dermatitis xerósica o de contacto irritativa y causar atrofia y dermatoporosis.

Estudio del efecto citotóxico e irritativo de jabones para la limpieza cutánea / Study of the cytotoxic and irritant effects of skin cleansing soaps

Resumen Introducción: El jabón para el aseo cutáneo es de empleo común entre la población, sin embargo, es posible que cause daño a las células de la piel y modifique la barrera cutánea. Objetivo: Determinar el efecto citotóxico de los jabones en queratinocitos cultivados in vitro y correlacionarlo con la irritación clínica. Método: Se realizó una encuesta para conocer los jabones comerciales más utilizados y su cantidad; posteriormente, se evaluó su citotoxicidad en cultivos de queratinocitos humanos mediante el método de resazurina. Los jabones con mayor y menor citotoxicidad se aplicaron en piel de voluntarios sanos para evaluar su efecto en la barrera cutánea mediante ensayos de colorimetría y pérdida transepidérmica de agua. Resultados: De los jabones analizados, 37 % demostró ser tóxico para los queratinocitos in vitro. El jabón con mayor toxicidad indujo el mayor índice de eritema y pérdida transepidérmica de agua, en comparación con el jabón menos tóxico y el vehículo empleado como solución control. Conclusión: Los jabones comercializados para el aseo cutáneo pueden incluir ingredientes químicos que dañan los queratinocitos humanos y causan irritación subclínica de la barrera cutánea. Su utilización puede agravar dermatosis preexistentes, generar dermatitis xerósica o de contacto irritativa y causar atrofia y dermatoporosis.

Abstract Introduction: The use of soap for skin cleansing is common among the population. However, it is possible that it causes damage to skin cells and disrupts the skin barrier. Objective: To determine the cytotoxic effect of soaps on in vitro-cultured keratinocytes and to correlate it with clinical irritation. Method: A survey was conducted to find out the most widely used commercial soaps and their number. Subsequently, their cytotoxicity was evaluated in human keratinocyte cultures using the resazurin assay. The soaps with the highest and lowest cytotoxicity were applied to the skin of healthy volunteers to assess their effect on the skin barrier using colorimetry and transepidermal water loss (TEWL) assays. Results: Of the analyzed soaps, 37 % were shown to be toxic to keratinocytes in vitro. The soap with the highest toxicity induced the highest rate of erythema and TEWL, in comparison with the least toxic soap and the vehicle used as the control solution. Conclusion: Soaps marketed for skin cleansing can contain chemical ingredients that damage human keratinocytes and cause skin barrier subclinical irritation. Their use can worsen preexisting dermatoses, generate xerotic or irritant contact dermatitis, and cause atrophy and dermatoporosis.

DNA Methyltransferases in Malar Melasma and Their Modification by Sunscreen in Combination with 4% Niacinamide, 0.05% Retinoic Acid, or Placebo.

BACKGROUND: Malar melasma has a chronic and recurrent character that may be related to epigenetic changes. OBJECTIVE: To recognize the expression and DNA methylation of DNA methyltransferases (DNMTs) in malar melasma and perilesional skin, as well as the changes in DNMTs after their treatment with sunscreen in combination with 4% niacinamide, 0.05% retinoic acid, or placebo. METHODS: Thirty female patients were clinically evaluated for the expression of DNMT1 and DNMT3b using real-time PCR and immunofluorescence. These initial results were compared to results after eight weeks of treatment with sunscreen in combination with niacinamide, retinoic acid, or placebo. RESULTS: The relative expression of DNMT1 was significantly elevated in melasma compared with unaffected skin in all subjects, indicating DNA hypermethylation. After treatment, it was decreased in all groups: niacinamide (7 versus 1; p<0.01), retinoic acid (7 versus 2; p<0.05), and placebo (7 versus 3; p<0.05), which correlates with clinical improvement. DNMT3b was not overexpressed in lesional skin but reduced in all groups. CONCLUSIONS: We found DNA hypermethylation in melasma lesions. Environmental factors such as solar radiation may induce cellular changes that trigger hyperpigmentation through the activation of pathways regulated by epigenetic modifications. However, limiting or decreasing DNA methylation through sunscreen, niacinamide, and retinoic acid treatments that provide photoprotection and genetic transcription can counteract this.

Analysis of cutaneous pigmentation in a sample / Análisis de la pigmentación cutánea en una muestra.

Background: The blend of hemoglobin, carotenes, and melanin defines the skin color. Constitutive pigmentation is genetically determined, facultative color is induced when skin is exposed to environment. The objective was to quantify both pigmentations in a sample of Mexican population and to analyze its relationship with sex, age, and phototype. Methods: We evaluated 259 individuals during the winter. Skin colorimetry was obtained by diffuse reflectance spectrometry, using the International Commission of Illumination coordenates. L*a*b* parameters were measured and the individual typological angle (ITA) was estimated from forehead, thorax, neck, forearms, and buttocks areas. Results: Facultative pigmentation differed from constitutive in L*, a*, and ITA° values. In men, L* and ITA° parameters were lower. Constitutive pigmentation was similar between sexes. Phototypes III, IV, and V showed differences in L*, b*, and ITA°. Facultative values such as L*, a*, ATI°, and the constitutive a* reduce as age increases. Conclusions: The cutaneous tones of a sample of population were quantified recognizing their values for white, light brown, and dark brown skin. A reference frame for research related to cutaneous pigmentation in Mexico is presented.

Antecedentes: La mezcla de melanina, hemoglobina y carotenos definen el color cutáneo. La pigmentación constitutiva está determinada genéticamente, la facultativa se induce cuando la piel se expone al ambiente. El objetivo fue cuantificar ambas pigmentaciones en una muestra de población mexicana, y analizar su relación con el género, edad y fototipo. Métodos: Se evaluaron 259 personas durante un periodo invernal. La colorimetría cutánea se obtuvo mediante espectrometría de reflectancia difusa utilizando las coordenadas de la Comisión Internacional de Iluminación. Se registraron los valores L*a*b* y se estimó el ángulo tipológico individual (ATI°) en frente, tórax, cuello, antebrazos y glúteos. Resultados: La pigmentación facultativa difirió de la constitutiva en los parámetros L*, a*, y ATIº. En hombres, los valores facultativos de L* y ATI° fueron menores. La pigmentación constitutiva fue similar entre sexos. Los fototipos III, IV y V muestran diferencias en L*, b* y ATI°. Los valores facultativos L*, a*, ATI° y el constitutivo a* se reducen al incrementarse la edad. Conclusiones: Se cuantificaron los tonos cutáneos de una muestra de población reconociéndose los valores para la piel blanca, morena clara y morena oscura. Se presenta un marco de referencia para estudios relacionados con la pigmentación cutánea en México.

[Allopurinol hypersensitivity syndrome. A report of two cases]. / Síndrome de hipersensibilidad por alopurinol. Informe de dos casos clínicos.

Patients in treatment with allopurinol are in risk of having life threatening adverse reactions particularly at the beginning of the treatment. Two percent of the patients prescribed with this drug have associated severe cutaneous adverse reactions. We present two cases of allopurinol hypersensitivity syndrome in mexican patients in which asymptomatic hyperuricemia was the indication to its use. The general physician and the specialist must be alert of this syndrome that causes elevate morbidity and mortality.

Los pacientes bajo tratamiento con alopurinol pueden presentar reacciones adversas potencialmente mortales, particularmente al inicio del tratamiento. Las reacciones cutáneas adversas por alopurinol tienen una prevalencia aproximada del 2 %. Presentamos dos casos de síndrome de hipersensibilidad por alopurinol en pacientes mexicanos en quienes la hiperuricemia asintomática fue la indicación para su uso. El médico general y el especialista deben estar alerta ante este síndrome que ocasiona alta morbilidad y mortalidad.

[Analysis of the cumulative solar ultraviolet radiation in Mexico]. / Análisis de la radiación solar ultravioleta acumulada en México.

BACKGROUND: The incidence of skin cancer has increased in Mexico in recent years. Ultraviolet radiation is the main risk factor associated. Due to the need to develop strategies to prevent skin cancer, the aim of the study was to estimate the UV intensity in several representative regions of Mexico, the average annual UV dose of these populations, and the potential benefit of applying sunscreen at different ages. METHODS: The intensity of UV radiation was quantified by remote and terrestrial radiometry. The dose of UV exposure was measured in minimal erythema doses using validated models for face and arms. The benefit of using a sunscreen was calculated with the use of a sunscreen with SPF 15 from birth to age 70. RESULTS: The UV radiation is lower in December and greater in the period from May to July. The region with a lower annual dose is Tijuana; and the higher annual dose is in the Mexico City area. The annual difference between these regions was 58 %. Through life, a low SPF sunscreen can reduce up to 66 % of the received UV dose. CONCLUSIONS: The geographical location is a risk factor for accumulation of UV radiation in Mexico. Since childhood, people receive high amounts of it; however, most of this dose can be reduced using any commercially available sunscreen, if applied strategically.

Introducción: La incidencia del cáncer de piel en México se ha incrementado en los últimos años. La radiación UV es el principal factor de riesgo asociado. Debido a la necesidad de desarrollar estrategias para evitarla, el objetivo del estudio fue estimar la intensidad UV en diversas regiones representativas del país, la dosis UV promedio anual de esas poblaciones y el beneficio potencial de la aplicación de un filtro solar a diferentes edades. Métodos: se cuantificó la intensidad de la radiación UV mediante radiometría terrestre y remota. La dosis de exposición UV se midió en dosis mínimas eritematógenas utilizando modelos validados para cara y brazos. El beneficio de realizar fotoprotección se calculó para el uso de un filtro con FPS 15 desde el nacimiento hasta los 70 años. Resultados: la radiación UV es menor en diciembre y máxima de mayo a julio. La localidad con menor dosis anual es Tijuana y la máxima el Distrito Federal. La diferencia anual entre estas regiones es de 58 %. Durante la vida, un filtro solar de baja potencia puede reducir hasta 66 % la dosis recibida. Conclusiones: la localización geográfica es un factor de riesgo para la acumulación de radiación UV en México. Desde la infancia, la población recibe dosis elevadas de radiación UV. La mayoría de esas dosis puede reducirse mediante cualquier filtro solar disponible en el comercio, si es aplicado de forma estratégica.

Relationship between transient receptor potential vanilloid-1 expression and the intensity of sensitive skin symptoms.

BACKGROUND: Sensitive skin (SS) is a hyper-reactive condition of the skin secondary to external factors, without objective signs of lesion. Its pathogenesis is still under investigation. Transient receptor potential vanilloid-1 (TRPV1) is a cation channel that responds to low pH and is related to nociception, neurogenic inflammation, and pruritus. AIMS: To determine the expression of TRPV1 in subjects with SS and correlate it with the degree of symptoms and skin pigmentation. PATIENTS/METHODS: We included 31 subjects self-diagnosed as having SS. Colorimetric values were obtained for assessment of skin phototype, and the lactic acid stinging test (LAST) was performed. Two skin biopsies from the nasolabial fold of each volunteer were obtained. Qualitative analysis of TRPV1 was carried out with immunohistochemistry. Quantitative analysis of TRPV1 was carried out with qRT-PCR. RESULTS: LAST was positive in 74% of the subjects, 56% of those having tan and brown skin. Immunohistochemistry staining for TRPV1 was greater in positive subjects (P = 0.03), but showed no correlation with the intensity of symptoms. Positive subjects also had higher TRPV1 mRNA expression compared to negative subjects (P < 0.001). This expression showed a positive correlation with the intensity of referred symptoms (R = 0.75, P < 0.001) and skin pigmentation (R = 0.63, P < 0.001). CONCLUSIONS: TRPV1 expression is upregulated in subjects with sensitive skin, and it correlates with the intensity of the symptoms. Our findings suggest a role for this receptor in the pathogenesis of sensitive skin syndrome.

Metastatic Calcinosis Cutis: A Case in a Child with Acute Pre-B Cell Lymphoblastic Leukemia.

Hypercalcemia in children with malignancy is an uncommon condition. It has been described in leukemia patients with impaired renal excretion of calcium or osteolytic lesions. Metastatic calcinosis cutis (MCC) may develop if hypercalcemia persists. We report the case of a 5-year-old girl with an atypical dermatosis and unspecific gastrointestinal symptoms. Considered clinical diagnoses were xanthomas, histiocytosis, molluscum contagiosum, and nongenital warts. Cutaneous histological analysis showed amorphous basophilic deposits in the dermis suggestive of calcium deposits. Laboratory tests confirmed serum hypercalcemia. Extensive investigations such as bone marrow biopsy established the diagnosis of an acute pre-B cell lymphoblastic leukemia. Hypercalcemia in hematopoietic malignancies is unusual, especially as initial manifestation of the disease. Careful review of the literature fails to reveal previous reports of these peculiar cutaneous lesions of MCC in children with leukemia.

Hailey-Hailey disease improved by fractional CO2 laser.

Hailey-Hailey disease (HHD), also known as benign familial pemphigus, is an autosomal dominant skin condition that affects the adhesion of epidermal keratinocytes. Although the initial manifestation of flaccid vesicles on erythematous or normal skin in flexure sites frequently goes unnoticed, large, macerated, exudative plaques of superficial erosions with crusting are observed at the time of diagnosis. There is no specific treatment for HHD, and most cases are symptomatically supported. However, infrared laser ablation has been somewhat helpful. We present a case successfully treated with fractional CO2 laser showing a long-term favourable outcome and no adverse effects. Thus, this modality could be an alternative to full ablation for this condition.

In vitro assessment of commercial sunscreens available in Latin America.

In Latin America, people have largely abandoned the practice of wearing hats and traditional clothing that provided skin protection. Sunscreen application has therefore become essential to protect against the increased sun exposure. The physician-prescribed medical-grade sunscreens provide sufficient sun protection but the requirement for regular use puts a financial burden on the patient that is often not sustainable. An appropriate sunscreen should provide a high and broad ultraviolet (UV) protection against UVB and UVA. Several over-the-counter (OTC) sunscreens have been developed for sale at affordable prices and are available for purchase in convenient locations, such as local grocery stores. The aim of this study was to assess the in vitro UV protection of 34 popular OTC sunscreens found in the Latin American market. UV absorbance/transmittance was quantified by diffusion transmission spectroscopy using coarse silica plaques. Photostability was tested by irradiating them with simulated solar light and calculating the sun protection factor (SPF), critical length of absorption (C lambda ), UVA/UVB ratio, and the spectral uniformity index (SUI). The results indicated that the in vitro SPFs were significantly lower than the value declared on the labels, particularly for those claiming high SPF values; however, the majority of these sunscreens offered high levels of UV protection. Considering the advantages of low cost and ample accessibility, we concluded that this sample of OTC sunscreens can be beneficial to the general public by providing some level of skin protection from solar radiation, and may be promoted to improve compliance with recommended photoprotection behavior.

In vitro assessment of commercial sunscreens available in Latin America / Valoración in vitro de protectores solares comerciales existentes en Latinoamérica

In Latin America, people have largely abandoned the practice of wearing hats and traditional clothing that provided skin protection. Sunscreen application has therefore become essential to protect against the increased sun exposure. The physician-prescribed medical-grade sunscreens provide sufficient sun protection but the requirement for regular use puts a financial burden on the patient that is often not sustainable. An appropriate sunscreen should provide a high and broad ultraviolet (UV) protection against UVB and UVA. Several over-the-counter (OTC) sunscreens have been developed for sale at affordable prices and are available for purchase in convenient locations, such as local grocery stores. The aim of this study was to assess the in vitro UV protection of 34 popular OTC sunscreens found in the Latin American market. UV absorbance/transmittance was quantified by diffusion transmission spectroscopy using coarse silica plaques. Photostability was tested by irradiating them with simulated solar light and calculating the sun protection factor (SPF), critical length of absorption (C λ ), UVA/UVB ratio, and the spectral uniformity index (SUI). The results indicated that the in vitro SPFs were significantly lower than the value declared on the labels, particularly for those claiming high SPF values; however, the majority of these sunscreens offered high levels of UV protection. Considering the advantages of low cost and ample accessibility, we concluded that this sample of OTC sunscreens can be beneficial to the general public by providing some level of skin protection from solar radiation, and may be promoted to improve compliance with recommended photoprotection behavior.

En Latinoamérica, la población ha abandonado la costumbre de usar sombrero y ropa tradicional para protegerse del sol. En consecuencia, es básico el uso de protectores solares si se realizan actividades bajo sol. Los protectores solares que se usan en la práctica médica son adecuados, pero su uso frecuente condiciona una carga económica que muchos pacientes no pueden solventar debido a sus costos considerables. Un protector apropiado contiene una amplia y elevada protección ultravioleta (UV) A y B. En las tiendas de conveniencia, existen numerosos protectores solares a precios más accesibles. El objetivo del estudio fue determinar la protección UV in vitro de 34 protectores solares con amplia presencia comercial (de venta sin prescripción médica) en el mercado latinoamericano. La absorbancia/transmitancia de la radiación UV se cuantificó mediante espectroscopía de transmisión difusa. Placas de sílice esmerilado fueron recubiertas con el producto y expuestas a radiación solar simulada para conocer su fotoestabilidad. Se calcularon índices como el factor de protección solar (SPF), longitud crítica de absorción (C λ), relación UVA/UVB y el índice de uniformidad espectral (SUI). Se encontró que el SPF in vitro fue inferior al establecido en las etiquetas, especialmente en aquellos con valores altos. No obstante, la mayoría de los protectores incluidos ofrecen niveles de protección UV elevados. Considerando su amplia accesibilidad y menor costo, concluimos que esta muestra comercial de protectores solares podría utilizarse en el entorno clínico para favorecer su apego junto a las otras medidas de fotoprotección sugeridas.

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.

Cutaneous congenital candidiasis in a full-term newborn from an asymptomatic mother.

A male infant of 2,900 g was born at term to a 19-year-old primigravida woman who had adequate prenatal care and no major complications detected during the pregnancy. The only reported medical event was an episode of urinary tract infection by E. coli one month before delivering, which resolved without complications using nitrofurantoin. There was no history of maternal herpes simplex infection and her serologic screening was negative for syphilis.

Use of Raman spectroscopy in the analysis of nickel allergy.

Raman spectra of the skin of subjects with nickel allergy are analyzed and compared to the spectra of healthy subjects to detect possible biochemical differences in the structure of the skin that could help diagnose metal allergies in a noninvasive manner. Results show differences between the two groups of Raman spectra. These spectral differences can be classified using principal component analysis. Based on these findings, a novel computational technique to make a fast evaluation and classification of the Raman spectra of the skin is presented and proposed as a noninvasive technique for the detection of nickel allergy.

Double-blind, placebo-controlled, randomized study comparing 0.0003% calcitriol with 0.1% tacrolimus ointments for the treatment of endemic pityriasis alba.

Background. Pityriasis alba (PA) is a frequent cause of consultation in tropical areas due to its chronic course, frequent relapses, and notorious hypopigmented lesions in pediatric dark skin populations. Currently, no treatment is widely accepted. Objective. To assess the efficacy of 0.0003% calcitriol and 0.1% tacrolimus ointments compared with placebo in the treatment of endemic PA. Methods. Twenty-eight children aged 3-17 years with 56 symmetrical lesions and phototype IV-V, were randomly assigned to receive the treatments on target lesions on the face. Improvement was evaluated at baseline and 8 weeks later clinically and by digital quantification of the affected area, colorimetry, and transepidermal water loss (TEWL). Results. Tacrolimus and calcitriol ointments induced a mean improvement of 68%, compared to 44% of placebo. We found an elevated TEWL in PA lesions. In the treated plaques, the reduction of the affected area was associated with improvement of pigmentation and TEWL. Conclusions. Calcitriol and tacrolimus induced similar repigmentation in endemic PA lesions. Melanogenic, anti-inflammatory, and barrier defect restoration properties of these drugs may explain these findings.