What is photoaging?
Photoaging is a phenomenon of skin aging caused by the reduction of collagen fibers and the deposition of abnormal elastic fibers in the skin due to long-term UV radiation.
What are the causes of photoaging?
Ultraviolet light is produced in nature by solar radiation, and its spectral wavelength is 180~400nm. It can be divided into three wavelengths according to the different biological effects of ultraviolet light: short-wave ultraviolet (UVC) wavelength is 180~290 nm, medium-wave ultraviolet (UVB) wavelength is 290~320 nm, and long-wave ultraviolet (UVA) wavelength is 320~400 nm.
In nature, light with wavelengths shorter than 290 nm can be absorbed and scattered by the air, clouds, dust particles and water vapor in the atmosphere, and the ultraviolet rays that reach the ground are mainly UVA and UVB, and different wavelengths of ultraviolet rays can be absorbed by different tissues in all layers of the skin, and the longer the wavelength, the stronger its penetrating ability. The longer the wavelength, the stronger the penetration ability.
1, external factors
UVA and UVB are mainly involved in the pathogenic process of photoaging, UVB irradiation can cause skin erythema and delayed pigmentation, destroy the moisturizing ability of the skin, make the skin rough and wrinkled, long-term UVB irradiation can make the skin keratin thickening, UVA is the main spectrum of skin tanning, its photochemical effect and photobiological effect is not as obvious as UVB, but the dose of UVA in sunlight is many times higher than UVB, and the penetrating ability is strong, penetrating into other tissues. UVA is the main spectrum of skin tanning and its photochemical and photobiological effects are not as obvious as UVB.
2, internal factors
Physiological factors: The pathogenic effects of skin photoaging begin to accumulate from the time of sun exposure, so attention should be paid to the protection of sun damage from infancy. In addition, as we grow older, the skin structure also changes accordingly, such as the integrity of epidermal stratum corneum, hydration and lipidation, epidermal thickness, color and the content of light-absorbing substances in the skin, etc. These factors can affect the reflection, scattering, absorption and penetration of ultraviolet rays in sunlight, thus affecting the development of skin photoaging.
The skin color is mainly determined by the melanosomes in the epidermis, which have good absorption of various wavelengths of ultraviolet and even visible and infrared light.
Pathological factors: A variety of dermatological diseases and pathological states can make the body more sensitive to UV radiation and clinical manifestations of mainly photodamage can occur.
Other factors: such as occupation, geographic latitude and altitude, etc.
What does photoaging look like?
It is mainly roughness, hypertrophy, deepening of skin furrows, elevation of skin crests, and leather-like appearance of exposed parts of the face and hands, which is called coarse and deep wrinkles; changes in skin microcirculation, such as capillary dilation or disappearance, and gray and lusterless appearance of the skin; it can also appear dirty pigment spots such as age spots or uneven pigmentation disorders.
How to prevent and control photoaging?
(A) Prevention of photoaging
1.Shading agent: shading agent can prevent or reduce the damage to the skin caused by ultraviolet radiation, so that the skin can be protected from further light damage and repaired. Generally, the sun protection factor (Sun Protection Factor, SPF) is used to measure the sunscreen effect of the shading agent, the product labeled SPF>15 can be. SPF only indicates the effectiveness of the shading agent against UVB, anti-UVA efficacy of the ingredients with PA, generally PA++–+++ on.
2, the internal use of photoprotective agents: nutritional deficiencies are prone to skin damage, and supplemental vitamins, carotenoids and polyunsaturated fatty acids and other nutrients have the role of protecting the skin from UV damage, which can increase the skin’s delayed hypersensitivity reaction and strengthen cell-mediated immunity.
3, However, it is more crucial to strengthen the education of the public to make them realize the harm of photoaging caused by UV radiation, so that they can consciously take some simpler but cost-effective physical measures to avoid light, such as: it is better not to be outdoors for 2 hours before and after noon in the summer season, and to wear wide brimmed hats and long-sleeved clothes when going out, which is actually the fundamental way to prevent the occurrence of photoaging.
(B) Treatment of photoaging
1.Oxidant: The use of free radical scavenging antioxidant supplementation therapy can prevent skin photo-oxidative damage, which not only has a protective effect on acute skin damage caused by ultraviolet radiation, but also can prevent UVB-induced chronic skin damage, therefore, antioxidants and shading agents generally form an efficient photoprotection system.
2, vitamin A: topical 0.05% all-trans retinoic acid emollient cream is currently the only product approved by the U.S. Food and Drug Administration can be used for photoaging treatment.
3, micronutrients polyunsaturated fatty acids n-3 in this regard is particularly significant, relying on its anti-inflammatory properties, can reduce the release of UV-induced cytokines and other cellular mediators to play its protective role.
4.Surgical treatment
Chemical exfoliation: the exfoliating chemical coating is applied evenly to the treatment area, so that the separation of the stratum corneum and protein coagulation occurs immediately and the epidermis and dermal papillae are necrotic to varying degrees and cause exfoliation, the greatest advantage of which is that the skin itself can be reshaped to appear more uniform and consistent appearance.
Laser treatment: Erbium:YAG laser technology emits infrared light for more precise excision of superficial degenerative tissues, and it removes aging and atrophied skin while performing a re-scaling process on photoaged skin.
CO2 laser and Er:YAG laser Intense Pulsed Light (IPL) treatment to improve photoaging skin. Dermabrasion: This is the process of grinding the skin with a dental drill driven abrasive head and high speed motor after local anesthesia or cryo.