Ethnic differences in stratum structure and function
Subjects with darker skin phenotypes appear tohave a greater protection against a mechanical challengeand chemical irritation than lighter skin phenotypesindicating a stronger stratum corneum (SC) barrier functiondespite having the reported lowest SC ceramide levels. Incontrast reduced SC natural moisturizing factor (NMF) levelshave been reported in Asian subjects compared withCaucasian and African American skin. Skin dryness is aproblem for everyone but skin ashing is a significant issue insubjects with skin of colour. This problem is due to theintrinsic skin background colour but differences in activitiesof certain desquamatory enzymes contribute to thisproblem and may also account for the differences in SCmechanical behaviour.