Skin type, but neither race nor gender, influence epidermal permeability barrier function

Area of Science:

• Dermatology
• Skin Physiology
• Epidermal Barrier Function

Background:

• Previous studies showed minimal differences in basal permeability barrier function across race and sex.
• Limited research assessed the stratum corneum's resilience and recovery from barrier insults.
• This study investigated epidermal permeability barrier function across different skin types, races, and sexes.

Purpose of the Study:

• To compare epidermal permeability barrier function in different human skin types, races, and sexes.
• To assess stratum corneum resistance to perturbation and recovery rates after barrier disruption.
• To determine if skin pigmentation influences epidermal barrier integrity and healing.

Main Methods:

• Compared transepidermal water loss (TEWL) in white vs. Asian, male vs. female, and skin types II/III vs. V/VI subjects.
• Measured basal TEWL using evaporimetry on the volar forearm.
• Assessed barrier integrity via tape strippings to reach a TEWL of ≥20 g/m²/hr and compared recovery rates at 6, 24, and 48 hours, and 1 week.

Main Results:

• No significant differences in barrier perturbation or recovery were found between white/Asian or male/female subjects.
• Skin types II/III required fewer tape strippings (29.6) to disrupt the barrier compared to skin types V/VI (66.7).
• Skin type V/VI demonstrated faster barrier recovery (43% at 6 hrs, 72% at 48 hrs) than skin type II/III (20% at 6 hrs, 55% at 48 hrs).

Conclusions:

• Darkly pigmented skin (Type V/VI) possesses a more resistant epidermal barrier that recovers more rapidly after disruption.
• Findings suggest potential implications for transdermal drug delivery efficacy across different skin types.
• Skin pigmentation influences the skin's ability to withstand environmental insults and recover from barrier damage.