Background: The pH of the stratum corneum (SC) in the elderly is elevated and linked to impaired SC function. Therefore, this paper addresses the question of whether acidic skin care generates positive clinical, biophysical, and microbiological effects in aged skin. Methods: This study was performed to assess skin care effects in nursing home residents (aged 80-97 years). Visual, biophysical, and microbiological methods were used. Subjects were randomly assigned to 1 of 2 groups and treated over 7 weeks with skin care products adjusted to a pH of 4.0 (group A) or a pH of 6.0 (group B). Results: Compared to baseline, SC integrity improved significantly in group A (p = 0.007), whereas there was no change in group B (p = 0.672). SC recovery 24 h after perturbation increased significantly in group A (p = 0.004) compared to baseline. The SC recovery in group B was not significant compared to baseline (p = 0.327). Conclusion: Long-term treatment with pH 4.0 skin care results in a significant improvement in epidermal barrier function compared to identical products with a pH of 6.0. In addition, effects on skin dryness and resident flora were demonstrated, but without significant differences, between the 2 groups. Based on these results, we recommend adjustment of skin care products for the elderly to a pH of 4.0 to maintain the health of aged skin.

The physiological skin surface pH is just below 5. With age the skin surface pH increases up to 6. An increased pH correlates with reduced barrier integrity/cohesion. The present pilot study assesses possible normalization of an increased skin surface pH of the elderly and improvement of barrier function via application of ≈pH 4.0 skin care products. Baseline skin surface pH was determined in elderly (80+ years old; n = 15) compared to middle aged adults (31 - 50 years old; n = 15). The effect of o/w emulsions at pH-values of 3.5, 4.0, 4.5 and 5.5 on the skin surface pH was determined in both groups. Further, the effect of a 4-week treatment with a pH 4.0 skin care product on the skin surface pH, skin hydration and barrier integrity was assessed. Thirteen elderly females were involved in this home-in-use test. Increased baseline skin surface pH of the elderly normalizes to the physiological pH of 4.5 - 5.0 over 7 hours after single application of o/w-emulsions with a given pH of 3.5 or 4.0. A 4 week treatment employing the pH 4.0 skin care product improves the epidermal barrier integrity of the elderly significantly (p = 0.005). Reduction of the increased baseline skin surface pH of the elderly is accompanied by improved epidermal barrier integrity. Skin care products for the elderly have to be adjusted in the pH range of 3.5 to 4.0

In summary, topical application of a pH 4.0 product containing plant oils improves epidermal barrier formation and SC lipid ordering and ratio in aged dry skin.

This study aimed to develop and validate an instrument for the assessment of patient-relevant benefit in dermatocosmetic treatment, i.e., skin care, of aged skin. Based on an open item collection with 33 elderly persons, items on patient-relevant treatment goals were collected. An expert panel selected 20 items to be most relevant and feasible for the questionnaire named Patient Benefit Index for Aged Skin (PBI-AS). The instrument, which assesses goal importance and achievement, was tested in a cognitive debriefing and validated in a longitudinal study (n = 80) along with the Dry Skin Area and Severity Index (DASI) and the Dermatology Quality of Life Index (DLQI) as convergent validation criteria. The cognitive debriefing showed the good practicability and feasibility of the instrument. Significant correlation with change in DASI (r = -0.527; p < 0.001) supports convergent validity of the PBI-AS. By contrast, correlation with DLQI was poor, indicating the different constructs. The PBI-AS is a valid and feasible tool for the patient-centered assessment of dermatocosmetic treatment benefit in aged skin.