Hipomelanosis macular progresiva / Progressive macular hypomelanosis

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Patrón de sensibilización por contacto a parafenilendiamina y su detección en tintes capilares / Pattern of Contact Sensitization to Paraphenylenediamine and its Detection in Hair

Introducción: Uno de los retos más difíciles en el campo de la Dermatología laboral es la identificación de las sustancias químicas con las que trabaja el enfermo para poder determinar su capacidad alergénica. Se han descrito múltiples técnicas para poder identificar las distintas sustancias alergénicas contenidas en la composición de las sustancias que maneja el enfermo. Estas pruebas de detección de alérgenos deben ser sensibles, específicas y seguras. Presentamos un estudio experimental cuyo objetivo es detectar la presencia de parafenilendiamina entintes capilares comercializados en nuestro país. Material y métodos: Hemos realizado un estudio experimental con el fin de realizar una detección cualitativa y semicuantitativa de parafenilendiamina en tintes capilares comercializados en nuestro país. Como técnica cualitativa utilizamos la técnica de identificación descrita consistente en la dilución del tinte con alcohol isopropílico y con posterioridad se añade la solución reactiva (1 g de vainilla en 15 ml de alcohol isopropílico y 7,5 ml de ácido clorhídrico). Esta prueba da una respuesta colorimétrica que indica la presencia o no del alérgeno en el tinte capilar. Con posterioridad hemos procedido a realizar un estudio cualitativo mediante la extracción del colorante con etanol 96◦, seguido de una cromatografía en capa fina monodimensional. Resultados: Se estudiaron un total de 15 tintes de color castaño o moreno y 12 tintes de color rubio. Este estudio nos permitió identificar la PPD en todos los tintes capilares morenos estudiados, con independencia de que su presencia estuviera indicada (n=12) o no (n=3) en la composición del tinte. Comprobamos la presencia de PPD en 6 de los 9 tintes rubios que indicaban la presencia de PPD en su composición y en 2 de los 3 que no la indicaban. La valoración semicuantitativa mediante cromatografía de capa fina nos permitió confirmar que la concentración de PPD utilizada en los tintes capilares de color moreno era superior (media del 3%) a la de los tintes rubios (media del 0,1-0,3%). Conclusión: La presencia de PPD en tintes capilares está en relación con la coloración del tinte, siendo constante en los de color oscuro y de intensidad baja en los rubios. Este estudio pone de manifiesto la importancia clínica y epidemiológica que tiene la identificación de alérgenos en la Dermatología, y de forma más concreta, en el campo de la Dermatología laboral (AU)

Background: One of the greatest challenges in occupational dermatology is the identification of chemical substances used by patients in their work in order to determine their allergenic potential. Numerous techniques have been described for the identification of allergenic compounds. These tests must be sensitive, specific, and safe. We describe a study to detect the presence of paraphenylenediamine (PPD) in hair dyes that are commercially available in Spain. Material and methods: We undertook an experimental study involving qualitative and semiquantitative detection of PPD in hair dyes sold in Spain. The qualitative technique we used was a previously described colorimetric method involving dilution of the dye with isopropyl alcohol followed by addition of a reagent solution (1 g of vanilla in 15 ml of isopropyl alcohol and 7.5 ml of hydrochloric acid). A quantitative study was then done in which the dye was extracted in 96% ethanol and subjected to 1-dimensional thin-layer chromatography. Results: A total of 15 brown and 12 blonde dyes were analyzed. PPD was identified in all of the brown dyes analyzed, irrespective of whether it was indicated (n = 12) or not (n = 3) in the composition. PPD was found in 6 of the 9 blonde dyes that indicated it in the composition and 2of the 3 in which it was not indicated. Semiquantitative analysis by thin-layer chromatography revealed that the concentration of PPD in brown hair dyes (mean, 3%) was higher than in blonde dyes (mean, 0.1-0.3%). Conclusions: The presence of PPD in hair dyes is related to the color of the dye. It is consistently present in darker dyes and at low levels in blonde dyes. This study highlights the clinical and epidemiological importance of identifying allergens in dermatology, particularly in occupational dermatology (AU)

[Pattern of contact sensitization to paraphenylenediamine and its detection in hair dyes]. / Patrón de sensibilización por contacto a parafenilendiamina y su detección en tintes capilares.

BACKGROUND: One of the greatest challenges in occupational dermatology is the identification of chemical substances used by patients in their work in order to determine their allergenic potential. Numerous techniques have been described for the identification of allergenic compounds. These tests must be sensitive, specific, and safe. We describe a study to detect the presence of paraphenylenediamine (PPD) in hair dyes that are commercially available in Spain. MATERIAL AND METHODS: We undertook an experimental study involving qualitative and semiquantitative detection of PPD in hair dyes sold in Spain. The qualitative technique we used was a previously described colorimetric method involving dilution of the dye with isopropyl alcohol followed by addition of a reagent solution (1g of vanilla in 15 ml of isopropyl alcohol and 7.5 ml of hydrochloric acid). A quantitative study was then done in which the dye was extracted in 96% ethanol and subjected to 1-dimensional thin-layer chromatography. RESULTS: A total of 15 brown and 12 blonde dyes were analyzed. PPD was identified in all of the brown dyes analyzed, irrespective of whether it was indicated (n = 12) or not (n = 3) in the composition. PPD was found in 6 of the 9 blonde dyes that indicated it in the composition and 2 of the 3 in which it was not indicated. Semiquantitative analysis by thin-layer chromatography revealed that the concentration of PPD in brown hair dyes (mean, 3%) was higher than in blonde dyes (mean, 0.1-0.3%). CONCLUSIONS: The presence of PPD in hair dyes is related to the color of the dye. It is consistently present in darker dyes and at low levels in blonde dyes. This study highlights the clinical and epidemiological importance of identifying allergens in dermatology, particularly in occupational dermatology.