What reason is allergy to the sun?

summary

When it comes to being allergic to the sun, it is actually allergic to ultraviolet light. It belongs to an abnormal photoallergic reaction. It is also called solar dermatitis. It often leads to severe itching, recurrent rashes, mossy changes and pigmentation, especially in hot weather, The incidence is more obvious. What reason is allergy to the sun? Let's talk about it

What reason is allergy to the sun?

UVA and UVB, two kinds of penetrating ultraviolet rays in the sun, can directly reach the dermis of the skin, making the skin of the people with allergic constitution exposed to the sun appear red, burning, hot, painful and other symptoms. This is commonly called solar dermatitis in medicine, that is, ultraviolet allergy; At the same time, ultraviolet radiation can also lead to a sharp increase of free radicals in the body, which can cause wrinkles, pigmentation, cell damage in local skin, and even change the immune system, causing more serious phototoxicity or photoallergic reaction.

After being exposed to the sun in midsummer, erythema and blisters appear on the exposed skin of neck, face, arm, shoulder and back. The burning itch is unbearable. After a few days, the erythema or edema subsides, and the skin on the affected area desquamate and molt, leaving temporary pigmentation. This process is an acute damaging reaction of the skin exposed to strong sunlight, that is, sunburn. After repeated sunburn, the skin will also be sensitive to light, and then exposed to strong sunlight, it will produce photosensitive reaction, that is, photodermatitis.

Conventional UV protection measures include sunscreen and anti UV sunshade. Sunscreen can only block part of UVA, but it is not very effective for UVB. Anti UV sunshade has nothing to do with the UV reflected from the ground and wall.

matters needing attention

Eat more food containing vitamin A and fresh vegetables and fruits to maintain normal skin function. On some may induce seasonal dermatitis of light sensitive food, should try to eat or not to eat. Try not to use hot water, alkaline soap or coarse towel when washing your face.