Abstract
INTRODUCTION: Facial moisturizers are commonly used by healthy women and increasingly men of all age groups. This study aimed to investigate the effects of moisturizer discontinuation and the subsequent evolution of symptoms. METHODS: Two prospective observational split-face comparison pilot studies were performed in Switzerland and enrolled (I) 20 healthy women aged 17-25 years in winter and (II) 36 female subjects 15-20 and 40-55 years of age in summer. Moisturizers were stopped on the investigational half of the face. On the control side, the usual skin care regimen was continued. Daily subjective (I/II) and objective (I) skin assessments for the occurrence of typical symptoms of dry skin (dryness, itching, scales, redness, wrinkles) were collected. RESULTS: In the winter study (cohort I) in both the subjective and objective assessment, all skin changes increased significantly within 1 day after discontinuation. On day 7, dryness (p < 0.001), itching (p < 0.025), redness (p < 0.001) and scales (p < 0.049) were significantly different in the subjective assessment and redness (p < 0.004) and scales (p < 0.001) in the objective assessment. Skin dryness reverted to baseline levels after 6 days in the objective assessment and 10 days in the subjective assessment. The control side's condition was reached after 6 days. In the summer study (II), only among the 15-20-year-olds was dryness significantly higher on the intervention side from day 1 (p < 0.028) to day 14 (p < 0.009). Their recovery time was 11 days until dryness intensity scores comparable to baseline were reached, and 21 days until the control side's values were matched. Over a 7-day period, the overall mean dryness score was significantly different between the interventional and control sides for both young and old participants. CONCLUSIONS: Both healthy young and aging female subjects react with typical symptoms of temporary dryness to a sudden stop of a previous long-term moisturizer treatment but regain normal levels quickly without continuation of moisturizers. The skin recovery time for skin dehydration is 1-3 weeks in young female subjects with varying intensities depending on the season.