Repigmentation patterns induced by NB-UVB and their relationship with melanocytic migration and proliferation in vitiligo.

BACKGROUND/PURPOSE: Vitiligo is the most commonly acquired depigmentation disorder of the skin and is characterized by the destruction of melanocytes. Ultraviolet phototherapy with narrow band (UVB-NB) induces proliferation, differentiation, maturation, and migration of melanocytes. The clinical repigmentation is featured by follicular, marginal, and diffuse patterns. The aim of this study was to observe the process involved in the melanocyte migration and proliferation among these patterns and the unresponsive lesions following UVB-NB phototherapy. The focal adhesion kinase (FAK) and c-KIT were used as markers of melanocyte migration and differentiation, respectively. METHODS: A total of 17 vitiligo patients under UVB-NB therapy were selected. The patients expressed the three repigmentation patterns as well as unresponsive lesions at the conclusion of a 30-session cycle. Skin biopsies were evaluated by immunohistochemistry and qRT-PCR. RESULTS: We found an increased expression of c-KIT in the follicular pattern compared to the diffuse pattern that was expressed predominantly of FAK. Marginal pattern expressed both proteins. The unresponsive achromic lesions showed poor expressions of both markers. CONCLUSION: Proliferation was prominent in the follicular pattern, but migration was prominent in the diffuse pattern. For the marginal pattern, both dynamics were present. The absence of these markers in vitiligo lesions suggests a lack of response to UVB-NB.

Goose skin in a girl with Ehlers-Danlos syndrome.

Pellagra is a nutritional disorder secondary to niacin deficiency. The classical triad is dermatitis, diarrhea, and dementia. We report the case of a young girl with hypermobility-type Ehlers-Danlos syndrome who exhibited the classical pellagra symptoms, despite apparent adequate nutritional intake. Her condition resolved after oral niacin supplements were administered. Although this association has not previously been recognized, an inherited connective tissue disorder may be related to the appearance of pellagra.

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.

[Environmental UV radiation levels for dosing PUVA-sol in Mexico]. / Niveles de radiación UV ambiental para dosificar el PUVA-sol en México.

BACKGROUND: PUVA-sol therapy has the advantage of its extensive availability and low cost. However, its use is empirical. The aim was to quantify the environmental UVA radiation and suggest a method for PUVA-sol administration. METHODS: we measured the UV radiation in the center of México (22 °N, 101 °W, 1877 m) by means of terrestrial radiometry from 2007 to 2011. We registered the variations according to hour, month, cloudiness and transmission through domestic silicate plates. RESULTS: more than 75 % of the UVA radiation is registered between the hours of 9:00 and 17:00. The annual lowest average intensity was 20 mW/cm(2) and the highest 25.4 mW/cm(2) (ANOVA, p < 0.001). The monthly UVA irradiation during the zenith for clear skies can be estimated by the following formula: 23.8 + 0.13 (month) - 0.13 (month - 6.5)(2), (r(2) = 0.95, p < 0.001). The commonly used silicate plate (3 mm) has a UVB absorbance of 0.93, and UVA transmittance of 0.58. CONCLUSIONS: the rational use of PUVA-sol is possible on the basis of the obtained data. It is necessary to isolate UVB radiation, and to adjust exposure during cloudy days, as well as following the safety protocol to obtain benefit and to reduce the risk of adverse effects.

Introducción: la terapia PUVA-sol tiene como ventaja su disponibilidad y bajo costo. Sin embargo, su utilización es empírica. La finalidad del estudio es cuantificar la radiación solar UVA ambiental y sugerir una forma de administración en México. Métodos: se midió la radiación UV en el centro del país (22 °N, 101 °O, 1877 m) mediante radiometría terrestre de 2007 a 2011. Se registró la variación por hora, mes, nubosidad y transmisión a través de placas de silicato doméstico. Resultados: más del 75 % de la radiación UVA se registra entre las 9:00 y las 17:00 horas. La intensidad anual promedio mínima fue de 20 mW/cm2 y la máxima de 25.4 mW/cm2 (ANOVA, p < 0.001). El cálculo de irradiación UVA mensual durante el cenit bajo cielo despejado puede estimarse mediante la fórmula: 23.8 + 0.13 (mes) - 0.13 (mes - 6.5)2, (r2 = 0.95, p < 0.001). La placa común (3 mm) de silicato doméstico tiene una absorbancia UVB de 0.93 y una transmitancia UVA de 0.58. Conclusiones: es posible el empleo racional de PUVA-sol según los datos obtenidos. Es necesario aislar la radiación UVB y ajustar la dosis según la nubosidad, así como apegarse al protocolo de seguridad a fin de obtener beneficios y minimizar los efectos adversos.