Partially unexpected age-dependent skin reaction to mechanical stress and mode of repair

Rana Elewa1,2, Emanuela Camera3, Monika Ottaviani3, Joachim Fluhr4, Mauro Picardo3, Armand Bernois5, Catherine Heusèler5, Christos C. Zouboulis1

1Departments of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Theodore Fontane Medical University of Brandenburg, Dessau, Germany; 2Department of Dermatology, Venereology and Andrology, Faculty of Medicine, Ain-Shams-University, Cairo, Egypt; 3Laboratory of Cutaneous Physiopathology and Integrated Center of Metabolomics Research, San Gallicano Dermatologic Institute, IRCCS, Rome, Italy; 4Department of Dermatology, Charité Universitaetsmedizin Berlin, Berlin, Germany; 5LVMH Recherche, Saint Jean de Braye, France

Skin aging is associated with alterations of surface texture, sebum composition and immune response. Skin care products target skin aging signs. The study evaluated by biophysical means skin quality parameters, response to mechanical stress and casual surface lipids in young and aged individuals, their subjective opinion and objective effectiveness of skin care products. Stratum corneum hydration, transepidermal water loss, skin pH, pigmentation and erythema were evaluated at baseline, 1, 6, 24 hours and 7 days, and casual surface lipid composition at the baseline and day 7 after mechanical stress induction at the forearms of 2 groups of healthy volunteers, younger than 35 years (n=11) and older than 60 years (n=13). Evaluations were also performed in stressed skin areas treated daily with skin care products and the subjective opinion of the volunteers was documented. The tested groups exhibited age-associated baseline skin functions as well as casual surface lipid composition and different reaction patterns to mechanical stress. The skin care products tested either normalized the skin reaction to stress more in younger than in older individuals or even worsened the skin function parameters. The subjective volunteer opinion correlated with the objective measurements.