Recent market research demonstrates that consumers often consider moisturizing benefits more important than anti-aging benefits.1 Rawlings and Voegeli have suggested that the tight sensation of dry skin might, in fact, be of greater concern than visible wrinkles; therefore, sensation might be more important than appearance.2 Surveys in Japan, the United States and France have also shown that as much as 40% of the female population perceives itself to have an issue with dry skin, and current moisturizing technologies do not meet the needs of these consumers.3
Delayed desquamation and the accumulation of corneocytes on the surface of the stratum corneum (SC) leads to dry skin. Rawlings and Voegeli therefore postulate that the future of moisturizers lies in controlling desquamation.2 In relation, at the Skin Forum 2013 event in London, these authors introduced the seven pillars of “corneocare,” targeting: the epidermal tissue at the molecular, cellular and structural level; epidermal function; tactile experience; appearance and sensation. This is one of the first concepts in personal care to close the gap between consumer perception and a scientific approach.
The concept of corneocare also was highlighted by DSM at the 2013 in-cosmetics Paris, where the company focused on “comfort science”—a holistic approach to epidermal skin sensation,4 connecting a youthful appearance to a healthy, functioning epidermis. This brings a different dimension to the SC by recognizing it as an interface for imparting visual and tactile sensory signal processing.5, 6 Rawlings presented on this subject as well, speaking as the Society of Cosmetic Scientists’ Medal Lecturer on Mar. 7, 2013, in London. Here, he focused on enhancing epidermal sensation by building a strong barrier function.
Corneobiology
Corneobiology is the basis for corneocare and corneotherapy. It was inaugurated as a new cutaneous discipline back in 1964, yet scientific findings of the SC’s diverse functions (see Stratum Corneum Functions) are still evolving.7 This discipline includes a broad range of research areas such as the anatomy, physiology and biology of the SC, but also encompasses immunology, endocrinology, neurobiology and psychology—i.e., a whole network of complex interactions. Albert Kligman, considered by many as the father of corneobiology, played an influential role in understanding these multiple functions.7 Prior to Kligman, the SC was thought to be an impermeable barrier, sealing the body from the outside world; but the SC is no longer considered a passive, inert, metabolically lifeless membrane: It is understood to be very much alive.8
The scientific basis of corneobiology has been further strengthened by the development of non-invasive methods to allow repeated, sequential observations of the same skin site without damaging the tissue. This field has attracted the attention of scientists from a range of disciplines, including molecular biologists, anatomists, physiologists, pharmacologists, geneticists and psychologists. In fact, scientific contributors stem from both industry and academia.9 Rawlings, for one, is well-respected for his comprehensive work on the biology of moisturization and functional skin care for dry skin conditions.10, 11
Corneotherapy
Kligman identified the SC as a smart tissue that acts as a biosensor for external environmental changes, reacting adaptively to restore homeostasis. In relation, topical preventive/therapeutic interventions have been developed that aim to repair damaged SC resulting from disease, genetics and a variety of mechanical, physical, chemical and psychological exogenous insults. Such forms of corneotherapy respect the principles of skin biology and show improved efficacy with benefits substantiated by an evidence-based approach.
Skin Care ‘Best Practice’ for Well-being
In a recent presentation to the Society of Cosmetic Scientists, this author argued that skin care is ultimately a tool to maintain skin health and well-being—allowing consumers to relax and feel comfortable. As is well-known, the skin envelops the entire body, and it has been suggested that an impaired skin barrier can alter mental health, or vice versa.12 Stress, social isolation and negative personality traits contribute to physical damage that can be repaired through restorative processes and behavioral interventions, i.e., sleep, diet, exercise; positive emotions and social interactions.13
For example, one plant-based diet14 and some essential oil aromatherapies15 have been shown to improve skin barrier function. Sleep disturbances also are known to alter endocrine signals, diminish skin health and accelerate aging.16 Stress and the quality of personal relationships can even impact skin barrier recovery.17
While the Quality of Life (QoL) measure has been used to assess the impact of physical appearance on personal attributes and the lives of healthy adults worldwide,18 research has also shown that people in highly industrialized countries, particularly Caucasian women, are less satisfied with their QoL regardless of greater access to skin and health care. This is due, in part, to society pressures but in this author’s experience, quantitative QoL data leads to many generalizations. Consumers are different, and skin care must fit into the narrative of their lives.
Therefore, a “best practice” in skin care should go beyond skin science. It should be a personalized, integrated practice that intertwines skin science with the comfort and care of traditional practices. Taking care of one’s appearance is a part of being human, and it strengthens positive emotions. These emotions influence the neurological pathways of almost all human thoughts. Modern science often gives little credit to the fact that listening, counseling and caring may alone be therapeutic. As Richard Horton, editor of Lancet, stated, “Part of the disquiet about modern science may be that it is too often silent about the lives of the people it purports to serve.”19 This approach will receive acceptance through evidence-based means only in its own time; at present, lack of evidence is not evidence of ineffectiveness.
The concept of corneocare, with a focus on epidermal sensation, is a step in the right direction. Personal grooming is a rewarding activity that releases endorphins and promotes a positive mood; however, the boundaries could be pushed further. The future of skin care should encourage whole body relaxation through touch and effective facial massage techniques, as touch is an important experience for the developing brain and for social well-being.20
References
1. The future of skin care: Capitalizing on emerging trends and changing preferences, available at datamonitor.com/store/Product/?productid=DMCM4720 (Accessed Aug 8, 2013)
2. R Voegeli and Anthony V. Rawlings, Corneocare–The key to understanding dry skin disorders, available at tukad.org.tr/tr/pdf/019%20Voegeli.pdf (Accessed Aug 8, 2013)
3. K Kitamura, Advances in dry skin care technology extend beyond the category of cosmetic products, IFSCC Magazine 5(3) 177–87 (2002)
4. DSM press announcement, available at dsm.com/content/dam/dsm/cworld/en_US/documents/2013-04-15-dsm-is-revealing-the-power-of-beauty-at-in-cosmetics-2013.pdf (Accessed Aug 8, 2013)
5. M Visscher, SB Hoath, E Conroy and RR Wickett, Effect of semipermeable membranes on skin barrier repair following tape stripping, Arch Dermatol Res Nov 293(10) 491–9 (2001)
6. SB Hoath, MM Donnelly, and RE Boissy, Sensory transduction and the mammalian epidermis, Biosens Bioelectron 5(5) 351–66 (1990)
7. AM Kligman, The biology of the stratum corneum, in The Epidermis, W Montagna and WB Lobitz WB, eds, Academic Press, New York, USA 387–433 (1964)
8. AV Rawlings, What is the cutaneous barrier? Nouv Dermatol 27 93–98 (2008)
9. Skin Barrier, PM Elias and KR Feingold, eds, Taylor & Francis, New York, USA (2006)
10. AV Rawlings, 50 Years of stratum corneum and moisturization research, IFSCC Magazine, 12(3) 169–72 (2009)
11. AV Rawlings and PJ Matts, Stratum corneum moisturization at the molecular level: An update in relation to the dry skin cycle, J Invest Dermatol, Jun 124(6) 1099–110 (2005)
12. M Denda, K Takei and S Denda, How does epidermal pathology interact with mental state? Med Hypotheses Feb 80(2) 194–6 (2013)
13. TF Robles and JE Carroll, Restorative biological processes and health, Soc Personal Psychol Compass (8) 518–537 (Aug 5, 2011)
14. F Puch, S Samson-Villeger, D Guyonnet, JL Blachon, AV Rawlings and T Lassel, Consumption of functional fermented milk containing borage oil, green tea and vitamin E enhances skin barrier function, Exp Dermatol 17(8) 668–74 (Aug 2008)
15. M Fukada, E Kano, M Miyoshi, R Komaki and T Watanabe, Effect of “rose essential oil” inhalation on stress-induced skin-barrier disruption in rats and humans, Chem Senses 37(4) 347–56 (May 2012)
16. Esteé Lauder Clinical Trial Finds Link between Sleep Deprivation and Skin Aging, available at uhhospitals.org/about/media-news-room/current-news/2013/07/estee-lauder-clinical-trial-finds-link-between-sleep-deprivation-and-skin-aging (Accessed Jul 17, 2013)
17. TF Robles, KP Brooks, HS Kane and C Dunkel Schetter, Attachment, skin deep? Relationships between adult attachment and skin barrier recovery, Int J of Psychophysiology 88(3) 241–252 (Jun 2013)
18. A Beresniak, Y de Linares, GG Krueger, S Talarico, K Tsutani, G Duru and G Berger, Validation of a new international quality-of-life instrument specific to cosmetics and physical appearance: BeautyQoL questionnaire, Arch Dermatol 148(11) 1275–82 (Nov 1, 2012)
19. R Horton, The unremitting rage of distinguishing ourselves, Lancet 379 2326 (2012)
20. TJ Ryan, Integrative medicine selects best practice from public health and biomedicine, Indian J Dermatol Mar 58(2) 132–41 (Mar 2013)
