Variations in AD epidemiology, clinical presentation, and disease course between racial/ethnic sub-populations have been reported.4-12 Despite higher incidence, SOC patients are under-represented in AD clinical trials.37 Epidermal skin barrier impairment and imbalance in skin microbiome composition are known to play an essential role in AD pathophysiology.19-21,24,25 Prebiotic emollient treatments decreased AD symptoms and severity as well as increased skin barrier function by normalizing skin microbiota.21,27-34 Here, we first demonstrate the clinical efficacy of a prebiotic skincare routine, consisting of a cleanser and moisturizer, in improving mild-AD and severe xerosis in ethnically diverse patients.
Depending on the patient's age and AD severity, lesion distribution and appearance greatly vary.1,13,25 In individuals with melanin-rich skin, hyper- or hypopigmentation, plus greater visibility of scaling and dryness are distinct features of AD and xerosis.4-12,26 The lack of visible erythema on darker skin may challenge a proper diagnosis and undercount the severity of the disease.39-41 In our study, we included two validated scales to assess AD severity, plus clinical imaging (Figure 5A-C) to document changes overtime. Dermatological evaluations, using IGA and EASI scales, demonstrated the significant improvement of global eczema appearance by the prebiotic skincare regimen in all AD subjects, regardless of race and ethnicity (Figure 1B & 1C). Notably, we observed a small
Depending on the patient's age and AD severity, lesion distribution and appearance greatly vary.1,13,25 In individuals with melanin-rich skin, hyper- or hypopigmentation, plus greater visibility of scaling and dryness are distinct features of AD and xerosis.4-12,26 The lack of visible erythema on darker skin may challenge a proper diagnosis and undercount the severity of the disease.39-41 In our study, we included two validated scales to assess AD severity, plus clinical imaging (Figure 5A-C) to document changes overtime. Dermatological evaluations, using IGA and EASI scales, demonstrated the significant improvement of global eczema appearance by the prebiotic skincare regimen in all AD subjects, regardless of race and ethnicity (Figure 1B & 1C). Notably, we observed a small
but significant reduction in global eczema severity only with EASI scale with cleanser alone at week 2 (Figure 1C). Additionally, expert grading of both visual and tactile skin roughness showed significant improvement with prebiotic regimen in all patients starting at week 4, plus significant reduction in skin desquamation levels in xerosis group (data not shown). In alignment with prior reports, our results suggest that both scales can be used to assess AD severity in ethnically diverse patients.41,42
Skin barrier dysfunction is associated with decrease skin hydration, plus elevated TEWL and skin pH levels, which all have been linked to inflammatory skin diseases, including AD and xerosis.17 Under in vitro conditions, higher pH levels were shown to promote S. aureus growth, suggesting that an acidic skin environment favors a balance skin microbiome for healthier skin.43 Recently, higher TEWL and skin pH levels were observed to be associated with increased likelihood for flare-up in AD patients compared to healthy subjects.44 Though no change in TEWL was observed, we demonstrated that the prebiotic skincare regimen significantly increased skin hydration and decreased pH levels in all xerosis subjects (Figure 2C & 2D). Interestingly, similar changes were observed in both normal and lesional skin of AD patients (Figure 2A& 2B), indicating that the prebiotic skincare regimen favors an acidic pH gradient to promote skin barrier strength and repair, plus normalize skin microbiota overtime.
Reported differences in skin barrier characteristics in racial/ethnic populations have been suggested.17,45-49 For instance, Young et al, showed that South African subjects had higher stratum corneum hydration and skin surface pH levels compared to Caucasian counterparts.46 Another study demonstrated that following tape-stripping, epidermal barrier recovery was faster in individuals with skin phototype V/VI, independent of race, compared to individuals with lower skin phototypes.48 Under our study conditions, no significant differences in assessed skin barrier properties were observed between racial/ethnic sub-populations in both AD and xerosis groups (Figure 2A-2D). Inconsistencies between studies results emphasize the need for further research to determine the variations in epithelial barrier properties between racial/ethnic groups and their clinical relevance to various skin conditions.
AD is associated with a significant patient-burden and impact on quality-of-life.1-4 Commonly burdensome AD symptoms include itch and pain from scratching, excessive dryness/scaling, and red/inflamed skin.2,3 In SOCs, AD-related symptoms, such as itch, pigmentary sequelae and scarring, may be more stigmatizing compared to white counterparts.4-9,50-52 Through a real-world cross-sectional study, Silverberg et al., demonstrated that black and Hispanic AD patients, enrolled in the CorEvitas AD Registry (July 2020-July 2021), showed significant higher itch sensation compared to white counterparts.50 Another study demonstrated that US nonwhite veterans associated greater burning sensation and scarring with their itch, plus experienced greater emotional impact than white counterparts.51 Consistent with these reports, we found that AD patients of color experienced greater itching sensation than white counterparts at baseline (Figure 3B), while xerosis patients of color observed greater reduction in itching intensity levels with prebiotic cleanser alone and regimen overtime (Figure 3D). Additionally, though all subjects perceived significant improvement in quality-of-life with prebiotic cleanser alone and regimen (Figure 4A), xerosis white patients experienced worse quality-of-life at baseline and greater improvement overtime than SOC counterparts (Figure 4C). These interesting findings could be attributed to the variations in skin barrier properties between racial/ethnic group, contributing to itch and xerosis, and to the cultural norms and preferences influencing the patient's coping strategy to manage and treat skin condition.45,50,53,54
AD is associated with a significant patient-burden and impact on quality-of-life.1-4 Commonly burdensome AD symptoms include itch and pain from scratching, excessive dryness/scaling, and red/inflamed skin.2,3 In SOCs, AD-related symptoms, such as itch, pigmentary sequelae and scarring, may be more stigmatizing compared to white counterparts.4-9,50-52 Through a real-world cross-sectional study, Silverberg et al., demonstrated that black and Hispanic AD patients, enrolled in the CorEvitas AD Registry (July 2020-July 2021), showed significant higher itch sensation compared to white counterparts.50 Another study demonstrated that US nonwhite veterans associated greater burning sensation and scarring with their itch, plus experienced greater emotional impact than white counterparts.51 Consistent with these reports, we found that AD patients of color experienced greater itching sensation than white counterparts at baseline (Figure 3B), while xerosis patients of color observed greater reduction in itching intensity levels with prebiotic cleanser alone and regimen overtime (Figure 3D). Additionally, though all subjects perceived significant improvement in quality-of-life with prebiotic cleanser alone and regimen (Figure 4A), xerosis white patients experienced worse quality-of-life at baseline and greater improvement overtime than SOC counterparts (Figure 4C). These interesting findings could be attributed to the variations in skin barrier properties between racial/ethnic group, contributing to itch and xerosis, and to the cultural norms and preferences influencing the patient's coping strategy to manage and treat skin condition.45,50,53,54
CONCLUSION
Collectively, our results demonstrate that a prebiotic skincare routine can effectively manage AD and xerosis-related symptoms to prevent long-term sequelae in diverse ethnically patients by reducing condition severity, strengthening skin barrier properties in both lesional and normal skin, while providing relief from itching sensation and improving patients' quality of life. The nuances observed in our study between racial/ethnic populations help support clinicians on disease management strategies to consider, plus advocate for patient preferences for better treatment outcomes, particularly for patients of color.
