Features of Skin Physiological Functions by Age Categories at Sixteen Sites on the Body

Abstract

Purpose: To clarify the features of skin physiological functions by age range at 16 sites on the body.

Methods: The subjects comprised 124 men and women aged in their 20s to 80s. Stratum corneum moisture content (hereinafter, ‘moisture content’), sebum content, trans epidermal water loss (TEWL), and pH were measured at 16 points on the body and compared according to the three categories: young/young adult, middle-aged, and elderly.

Results/Conclusions: Water content was higher in the forearm flexor region and lower on the foot dorsum in elderly subjects compared to young/young adult and middle-aged subjects. Sebum content was higher on the posterior neck and upper back regions in young/young adult subjects compared to middle-aged and elderly subjects. Further, TEWL was lower in the forearm extensor region in elderly subjects compared to young/young adult subjects, and lower in the forearm flexor region in middle-aged subjects compared to young/young adult subjects. Although some variation was observed by site, pH was weakly acidic for all age ranges. Despite there being some age-related drops, overall evaluation based on water content, sebum content, and TEWL clarified sites with good overall evaluation (upper back region, anterior chest region) and sites with bad overall evaluation for all age ranges (hand dorsum, foot dorsum, femoral region, abdominal region). Results revealed sites requiring interventions, such as supplementing moisture and sebum content, and wiping gently without chafing while caregiving.