A. What is cosmetic allergy? Cosmetic adverse reactions include cosmetic contact dermatitis, cosmetic photosensitive dermatitis, cosmetic acne, cosmetic skin pigmentation abnormalities, cosmetic hair damage and cosmetic nail damage. Cosmetic allergy is a cosmetic-induced contact dermatitis, which is the main type of cosmetic-induced adverse reactions. 1, definition: when using cosmetics within 24 hours of the appearance of redness, swelling, itching, heat, pain five symptoms to be called cosmetic contact allergy. 2, clinical manifestations are: excessive redness in the butterfly area of the face, sometimes with a slight edema of the eyelids. Cosmetic allergy must be a product problem? 1, in fact, there are many factors that affect the skin irritation of cosmetics, such as the way the product is used, the frequency of use, the time the product works in the skin mucosa, the concentration of stimulating factors, the skin’s defense against irritants, etc. 2. Adverse reactions caused by cosmetics are quite common in the general population, but only about 10% of them are cosmetic allergies. What are the main substances that cause allergies? Skin allergies are caused by certain ingredients in cosmetics that stimulate skin cells and cause skin cells to produce antibodies, resulting in allergies. There are several common allergens in cosmetics used by both adults and infants. The most common cosmetic allergens are fragrances, preservatives, and heavy metals. 1, heavy metals mainly refers to some of the generation of peeling, whitening properties of lead, mercury content exceeds the standard cosmetics. 2. Fragrances are the most common allergenic substances in cosmetic raw materials, especially those that are now chemically synthesized. Eczema patients with allergic reactions to cosmetics 30% to 45% of the spices caused. Over the years, research has found that cosmetics using fragrances, including perfumes, mainly 26 kinds of fragrance ingredients are easy to cause allergies. Including: jasmine flavor, new international flavor, tuberose A flavor, white rose flavor, lilac flavor, osmanthus flavor. 3, preservatives: China’s regulations stipulate that cosmetics can only be used from 55 kinds of preservatives allowed to choose. But these 55 preservatives are not all safe. For example, formaldehyde is our regulations allow the use of preservatives, but some literature reports that they are the main preservatives that cause cosmetic allergies. If people with genetically sensitive skin use cosmetics in a hypersensitive state, they are highly susceptible to cosmetic contact dermatitis and aggravation of existing diseases. How to avoid cosmetic allergy? In order to prevent skin allergy, before buying cosmetics or after buying cosmetics, do not apply them directly on your face first, you must do the skin allergy test of cosmetics first. 1, cosmetic skin allergy test methods: (1) professional method: first wet a piece of gauze with distilled water or physiological saline, wring to half dry, and folded into four layers of about 1 square centimeter size, the cosmetics coated on one side of the gauze, and then put on the forearm or back normal skin, and then covered with 1.5 square centimeters of airtight cellophane or plastic film, fixed with adhesive tape. (2) or simple test method: apply a very small portion of the cosmetic product on the extended side of the forearm or on the normal skin of the back or on the location of the mastoid behind the ear. 2. After 24 to 48 hours of observation: (1) If the test site itches or burns severely, indicating that the cosmetic is irritating to the skin, it is a positive reaction, and the test substance should be removed promptly and rinsed with water. (2) If the test site does not have any symptoms, the reaction is negative, indicating that the cosmetic is not irritating to the skin and is safer. (3) If there is simple erythema and itching, it is a weak positive reaction; if there is redness and papules, it is a moderate positive reaction; if there is significant redness, papules and blisters, it is a strong positive reaction; if there is significant blistering or even necrosis, it is a very strong positive reaction. The presence of a positive reaction, in addition to timely cleaning and treatment, suggests that the cosmetic product should never be used.