IL1A and Erythema: The studies required controlled on‐site daily application (minus weekends) of an oil‐in‐water emulsion skin care formulation containing pHCA, Nam, Octinoxate, or a combination of pHCA with Nam and the measurements taken included chromameter L*a*b readings and expert grading of redness to assess erythema changes, AquaFlux TEWL to measure barrier integrity, digital imaging to visualize erythema differences, and D‐squame tape strip collection to quantitate changes in the inflammatory biomarker ratio IL1‐RA/IL‐1α (Study 1 only).