Evaluation of skin barrier biomarkers in diverse patients with xerosis and atopic dermatitis

Summary: Abstract Body: Though patients of color experience higher Atopic Dermatitis (AD) incidence, they show less frequent filaggrin (FLG) loss-of-functions mutations compared to white counterparts, indicating another plausible mechanism contributing to disease prevalence. Deficiency in Natural moisturizing factors (NMF), water-retaining molecules in the stratum corneum, have been found in xerosis, plus are associated with FLG loss-of-functions mutations in AD patients. Given the variations of AD across racial/ethnic groups, here we investigated skin barrier properties of diverse patients with AD & Xerosis in a monocenter single-blinded study. 40 subjects from diverse racial/ethnic backgrounds, aged 3-80 years old and presenting with mild-AD or severe xerosis completed study. After dermatological evaluations, all subjects started using a cleanser and moisturizer skincare regimen for 10 weeks. Evaluations of patients’ legs included NMF analysis, corneocyte assessment using scanning electron microscopy, clinical grading and instrumentation at week 0 and 10. Following 10 weeks of skincare regimen, all patients showed significant reduction in severity, increased skin hydration and decreased pH levels on both normal and lesional skin. Tape-stripping analyses of xerosis and AD corneocytes demonstrated significant higher surface isotropy and increased NMF levels following skincare regimen, indicating improvement of skin barrier integrity. Interestingly, sub-analyses comparisons between racial/ethnic groups revealed that xerosis patients of color consistently showed significant lower NMF basal levels compared to white counterparts. Lower NMF levels were also observed only on normal skin of AD patients of color. In summary, our findings suggest that a skincare regimen can effectively decrease AD and xerosis severity and improve symptoms by restoring skin barrier integrity in diverse ethnically patients. Lower NMF levels in patients of color first identified in our study may contribute to racial/ethnic variations in skin-barrier compromised conditions prevalence. Hawasatu Dumbuya¹, Katharine Podimatis¹, Zoe D. Draelos² 1. L'Oreal USA Inc, New York, NY, United States. 2. Dermatology Consulting Services, PLLC, High Point, NC, United States. Minoritized Populations and Health Disparities Research