Correlation between pH and irritant effect of cleansers marketed for dry skin

Authors

  • Lourdes Baranda,

    Corresponding author
    1. From the Servicio de Dermatología Hospital Central “Ignacio Morones Prieto”, and Departamento de Inmunología de la Facultad de Medicina de la Universidad Autónoma de San Luis Potosí, San Luis Potosí, México
      Lourdes Baranda, md, Facultad de Medicina de la Universidad Autónoma de San Luis Potosí, Avenue Venustiano Carranza 2405, 78210 San Luis Potosí, S.L.P., México. E-mail: baranda@uaslp.mx
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  • Roberto González-Amaro,

    1. From the Servicio de Dermatología Hospital Central “Ignacio Morones Prieto”, and Departamento de Inmunología de la Facultad de Medicina de la Universidad Autónoma de San Luis Potosí, San Luis Potosí, México
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  • Bertha Torres-Alvarez,

    1. From the Servicio de Dermatología Hospital Central “Ignacio Morones Prieto”, and Departamento de Inmunología de la Facultad de Medicina de la Universidad Autónoma de San Luis Potosí, San Luis Potosí, México
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  • Carmen Alvarez,

    1. From the Servicio de Dermatología Hospital Central “Ignacio Morones Prieto”, and Departamento de Inmunología de la Facultad de Medicina de la Universidad Autónoma de San Luis Potosí, San Luis Potosí, México
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  • Victoria Ramírez

    1. From the Servicio de Dermatología Hospital Central “Ignacio Morones Prieto”, and Departamento de Inmunología de la Facultad de Medicina de la Universidad Autónoma de San Luis Potosí, San Luis Potosí, México
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Lourdes Baranda, md, Facultad de Medicina de la Universidad Autónoma de San Luis Potosí, Avenue Venustiano Carranza 2405, 78210 San Luis Potosí, S.L.P., México. E-mail: baranda@uaslp.mx

Abstract

Background Although it is important that dermatologists and the general population know the irritation potential of products marketed for dry skin used for body cleansing, this information is not usually available.

Objective To assess the irritative effect of different soaps and liquid cleansers recommended for sensitive skin. To study the correlation of the irritation effect of each substance with its pH and with the presence or absence of syndet in the product.

Methods Seventeen products marketed for dry skin and 12 common soaps used by the general population were studied. Fresh soap emulsions (8%) were applied to the volar side of the right forearm of 30 individuals with sensitive skin for 5 consecutive days using aluminum chambers. The appearance of irritation (erythema, scaling and fissures) was recorded, scored, and expressed in an Irritation index (IrIn). The pH of each solution was measured.

Results Products with a low IrIn were White DoveTM (Dove, Lever Pond’s, Toronto, Ontario, Canada), Dove BabyTM, CetaphilTM (bar) (Cetaphil, Gulderma Lab., Forth Worth, TX, USA), Dove liquid cleanser for handsTM, Dove pinkTM, and AdermaTM (Adenma, Pierre Fabre, Dermo-Cosmetique, Boulagne, France). Most corresponded to syndet products. Among the most used brand-name soap, Camay ClassicTM (Camay, Procter & Gamble de Mexico, México, U.F.) had the lowest IrIn. Dove BabyTM was the only product with a neutral pH. A significant correlation between pH and the IrIn of cleansers was found (P < 0.006).

Conclusions Most products recommended for sensitive skin have a considerable irritation effect, which is related to the pH of the product. Better regulation of advertisement specifications including the pH level and type of cleanser contained is necessary for the majority of soaps and cleansers.

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