Summer is the season of the year with the highest intensity of UV rays. It is well known that UV rays in the sun can cause damage to human skin, in addition to the common sunburn, photoaging, but also lead to many photosensitive skin diseases such as photosensitive dermatitis, polymorphous sun rash, light flat moss and so on. Wang Lijun, Department of Dermatology, Wuxi Hospital of Traditional Chinese Medicine
Sun protection is an important way to prevent photosensitive dermatoses. Ultraviolet light is divided into long-wave ultraviolet (UVA), medium-wave ultraviolet (UVB) and short-wave ultraviolet (UVC) according to wavelength. UVC does not reach the ground, almost harmless to the human body; UVB has mainly light burns and photoaging effects on the human body, which is more harmful; and UVA mainly has tanning and skin wrinkling and relaxation effects on the human body, and is also the main photosensitive skin disease causative spectrum. Although the biological activity of UVA is only one-thousandth of the same dose of UVB, but the UVA that reaches the ground accounts for 98% of the total energy of UVB, and the penetration of the skin is also stronger than UVB and can accumulate in the body, so when choosing sunscreens should also pay attention to the protection of UVA.
Another cause of photosensitive skin disease is exposure to or consumption of certain drugs (tetracycline, memantine, chlorpromazine, aspirin, etc.), vegetables (bamboo shoots, lettuce, mushrooms, celery, etc.), food and food additives, etc. and then caused by phototoxic reactions or photomimetic reactions after exposure to light. Therefore, for this type of disease, both doctors and patients should cooperate to investigate the suspected allergens, and if necessary, to confirm the light patch test, and then to avoid contact with the targeted line.
Commonly used western medicine treatment methods are external corticosteroids, internal antihistamines and hydroxychloroquine. According to Chinese medicine, the disease is caused by congenital endowment intolerance or dampness and heat. According to the theory of Chinese medicine, most of the medicines used are based on clearing heat and benefiting qi, cooling blood and relieving dampness, such as Artemisia annua, Radix et Rhizoma, Radix et Rhizoma, Radix Angelicae Sinensis, Radix et Rhizoma, Sophora japonica, Salviae Miltiorrhiza, Radix Astragali, etc. Modern research on Artemisia has the function of regulating the immune system, while the active ingredients of Astragalus, Danshen and Bitter Ginseng, such as Astragalus polysaccharide, Angelica polysaccharide and Bitter Ginseng total alkaloids, all have anti-radiation effects against antioxidant free radicals.