INDIVIDUAL ARTICLE: Efficacy of a Prebiotic Skincare Regimen on Improving Mild Atopic Dermatitis and Severe Xerosis in Diverse Ethnically Patients

The investigational area in this study were the legs. The severity of xerosis and AD were visually assessed by clinical expert grading. AD was evaluated using two different validated scales: 1) Investigator Global Assessment (IGA) and 2) Eczema Area and Severity Index (EASI); while xerosis was assessed using the Overall Dry Skin (ODS) scale. Safety and tolerance were evaluated throughout the study by dermatologically assessing the symptoms of erythema, edema, peeling and dryness, plus by subject reporting the degree of burning, stinging, tingling, tightness and itching on investigational area using an internally validated scale, ranging 0 (absence) to 3 (severe). 

Skin hydration and pH levels were assessed using a corneometer (Dermalab, Cortex Technologies, Hansund, Denmark) and pH probe meter (Dermalab, Cortex Technologies, Hansund, Denmark) respectively. TEWL was assessed using a Tewameter (RG, Cyberderm, Broomall, PA). All instrumental evaluations were performed on both normal and lesional skin for AD patients.

Two (2) different self-assessment questionnaires were given to all subjects to evaluate the impact of the skin conditions and perceived benefits of the prebiotic skin-care regimen: 1) Dermatology Life Quality Index (DLQI) questionnaire to assess quality of life, and 2) Worst Itch Numeric Rating Scale (WI-NRS) questionnaire to assess itch intensity during the previous 24-hour period.

Clinical images of AD and xerosis patients' legs were taken at baseline, week 2 and 10 using SkinCam, a portable camera with crossed polarization modalities.³⁸

All clinical assessments of efficacy and tolerance parameters were expressed in terms or raw and change from baseline data, by time and skin condition (xerosis and AD) group. All clinical assessments of efficacy and tolerance parameters were analyzed using a linear mixed model. Checking normality of data was done by using a normal probability plot of model residuals (qqplot). In case of huge departure from normality assumption, a non-parametric test was preferred (Wilcoxon test at each time point). Benjamini Hochberg's adjustment was used for multiple comparison of all defined primary criteria. P-values < 0.05 were considered statistically significant.

A hundred-and thirty-eight (138) subjects from diverse racial/ethnic backgrounds with a mean age of 42 + 9 years old completed study with evaluable data, consisting of sixty-nine (69) subjects presented with mild AD, and 69 subjects with moderate to severe xerosis (Figure 1A). Starting at week 4, the prebiotic skincare regimen significantly improves global eczema appearance in AD subjects, reaching 86% and 93% reduction in IGA and EASI scores respectively by week 10 (Figure 1B & 1C). In xerosis subjects, we observed significant improvement in overall xerosis appearance with cleanser alone at 2 weeks, reaching 83% reduction by week 10 with prebiotic regimen (Figure 1D). 

Next, we investigated the efficacy of the prebiotic regimen on skin barrier properties in AD and xerosis groups. TEWL showed no relevant change overtime in both groups (data not shown).
 

Starting at week 4, instrumentation demonstrated a significant increase in skin hydration and a decrease in skin pH levels on both normal and lesional skin in AD patients (Figure 2A & 2B), plus showed similar outcomes in xerosis subgroup (Figure 2C & 2D). These results suggest that the prebiotic skincare routine strengthens skin barrier properties overtime.

To further elucidate the impact of AD and xerosis in patients, plus perceived benefits of the prebiotic skincare regimen, we assessed itching symptoms and quality-of-life using self-assessment questionnaires. AD subjects perceived significant reduction in itching sensation with cleanser at week 2, reaching complete relief with regimen