The base of the pyramid was focused on protection and repair. Originally, protection from UVA/UVB radiation was considered along with the resulting DNA damage. Now, many more sources of external skin trauma beside solar radiation have been identified, including air pollution, digital pollution (blue light), burning tobacco, abnormal circadian rhythms, high temperature from infrared radiation, and alterations to the microbiome. The middle of the pyramid was focused on renewal, involving moisturization, exfoliation, and cell turn over. More sophisticated moisturizers are now possible due to the development of new cosmetic ingredients, such as hyaluronic acid, synthetically produced on the human model of dermal glycosaminoglycans. Finally, the top of the pyramid focused on dermal stimulation with activation and regeneration induced by peptides and growth factors, but we can now also add stem cells to the list of available technologies.
This updated skin health and beauty pyramid includes newer introductions since 2014 to present the physician, skin care professionals, and patients with a current organized hierarchical approach to healthy skin.
Pyramid Base: Protection and Repair
The basis for any skin care regimen must be sun protection in the form of sunscreen. Sunscreens are considered over-the-counter (OTC) drugs in the United States and as such new sunscreen ingredients must be approved by the FDA. No new sunscreen active ingredients have been approved since 2014, yet technology has improved with less greasy, sticky vehicles that are more consumer acceptable. While the consumer may apply more sunscreen more frequently due to better aesthetics, sunscreen technology in terms of better ingredients for photoprotection has come to a standstill. Yet, sunscreens that protect against UVA and UVB radiation are only part of the story. It is now widely recognized that near infrared (IRA; 760–1400 nm), visible light (400–760 nm), and blue light can induce skin damage.
Visible light accounts for 40–45% of the electromagnetic radiation reaching the skin from the sun inducing the formation of reactive oxygen species and promoting photoaging. Visible light causes pigment darkening in Fitzpatrick skin types IV–VI more rapidly than UVA radiation possibly accounting for challenges in treating melasma and post-inflammatory hyperpigmentation in this population. The inorganic sunscreens that are optically opaque filters, such as zinc oxide and titanium dioxide, can reflect and scatter visible light when used in non-nano forms. These sunscreen ingredients should be included in products selected for antiaging purposes, especially in higher