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.

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.

No abstract

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.

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.

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.

ResumenAntecedentes: 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.

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.