Dermatitis and eczema are often used as synonyms to refer to a kind of skin inflammation, which represents the allergic reaction of the skin to various substances such as chemicals, proteins, bacteria and fungi. Eczema has no special meaning, while dermatitis has a limited meaning. If dermatitis is used instead of eczema as a diagnostic term, it refers to the combined reaction of dermis and epidermis, which can be acute, subacute and chronic. The three can exist together.
In hot summer, when people enjoy the pleasure brought by beautiful sunshine and summer clothes, they do not know that the exposed skin can cause acute skin inflammation after strong sunlight. Generally, within a few hours after exposure to the sun, the exposed parts have skin redness, swelling, burning and pain. In severe cases, swelling, blisters and burning pain can be seen on the skin, and erosion and scab can be seen after breaking. If the sun exposure area is wide, it will be accompanied by fever, headache, nausea, vomiting and other symptoms, which is solar dermatitis.
Solar dermatitis is an acute skin phototoxic reaction caused by excessive sunlight exposure at the exposed part of the skin. Solar dermatitis mostly occurs in hot summer. According to the characteristics of blistering skin after exposure to the sun, it is called “sunburn sore” in traditional Chinese medicine. Western medicine is divided into sunburn and pleomorphic solar dermatitis according to its pathogenesis and clinical manifestations. In order to avoid the harm of ultraviolet rays in the sun, people hold up umbrellas, wear sunshade sleeves and sunglasses in midsummer. However, even under such strict prevention, some people will still have all kinds of skin damage.
The so-called sunburn is caused by the acute inflammatory reaction of the irradiated part of the skin after excessive exposure to UVB in the sun. Due to the superficial effect of UVB, it is only manifested in the epidermis of the skin. After strong sunlight irradiation, it will soon cause skin epidermal keratinocyte necrosis and release media, resulting in dermal vascular dilatation, resulting in tissue edema. Subsequently, melanocytes accelerate the synthesis of melanin under the strong irradiation of sunlight, so as to blacken the suntanned skin. Therefore, most sunburn injuries occur 4-6 hours after strong sunlight exposure, with obvious erythema on the irradiated skin. In severe cases, edema can occur, reaching the peak in 12-24 hours. Accompanied by local burning or tingling, some may have local itching. More serious cases may cause systemic symptoms, such as fever, headache, nausea, vomiting, etc. Pleomorphic solar dermatitis is characterized by erythema, papule, wind mass or blister in different shapes in exposed parts, such as face, neck, extension of forearm, back of hand, etc. The most characteristic of this performance is that the sun is aggravated and the light is reduced.
There are many causes
Sunburn dermatitis, also known as sunburn or sunburn, is an acute inflammatory reaction of normal skin after exposure to the sun. It is characterized by erythema, edema, blisters, pigmentation and desquamation. The disease is common in late spring and early summer. It is common in children, women, skiers and surface workers. The intensity of reaction is related to light intensity, irradiation time, individual skin color, constitution, race, etc.) The disease is not caused only by sunlight, but for a variety of reasons. Strong light irradiation. Light poison is one of the poisonous evils, which is caused by sunlight. In the process of phototoxicity, the patient is exposed to the sun, Yang heat and toxin invade the body surface, accumulate depression on the skin, burn the skin and hurt the muscle, so the skin is red, swollen and hot; The evil toxin causes the damp heat in the body to occur outside the skin, so there are swelling, blisters, erosion and exudation. Food and drug factors.
Some foods contain photosensitive substances, such as spinach, rape, Grifola, milkvetch, Magnolia, shepherd’s purse, amaranth, purslane, celery, eggplant, potato, cucumber, tomato, red grape, fig, radish, mango, agaric, snail, notopterygium, Psoralea, white chrysanthemum, Angelica dahurica, etc. When eating these foods or drugs, the photosensitive substances in them will accumulate in the body. When reaching a certain concentration, the skin of the exposed parts of the human body (face, hands and feet) can cause metabolic disorders and induce dermatitis through direct sunlight. This dermatitis is also known as “plant solar dermatitis” and “mud snail solar dermatitis” in medicine.
Physical factors. Traditional Chinese medicine believes that the disease occurs suddenly due to intolerance, endogenous blood heat, eating hair, imbalance of spleen and stomach, endogenous damp heat, multiple sun exposure and heat toxin. Generally speaking, people with white and dry skin are more sensitive to sunlight. Generally, people with white and dry skin are more sensitive to sunlight than those with oily skin and black skin. In addition, some diseases can be induced or changed by the sun, the most obvious is lupus erythematosus. 30% of lupus erythematosus patients are sensitive to sunlight.
These patients should try to avoid sunlight. Clothes to wear. Some chemical fiber fabrics have poor sweat absorption and ventilation performance and weak reflective effect, so they are not ideal for sunscreen and sunshade. Wearing such clothes can not reduce sunlight exposure and achieve sunscreen and sunscreen effect, but increase solar radiation heat energy. For example, the absorption rate of camouflage clothes is up to 95%