In recent years, the variety and quantity of cosmetics has increased dramatically, and cosmetic beauty is almost an essential homework for office workers. There is also a growing trend of cosmetic dermatitis, which is characterized by allergic reactions once discontinued or used again; or allergic reactions on the face after the first use; or reactions after sunlight exposure after use. What is cosmetic dermatitis? Cosmetic dermatitis is an inflammatory skin disease of the face or other areas of the skin that is caused by the use of cosmetics or makeup. It is characterized by erythema, edema, blisters, papules, oozing, crusting, itching, hyperpigmentation, and more importantly, persistent dryness, increased sensitivity, and acne-like lesions on the skin of the face and makeup areas. What causes cosmetic products to cause adverse reactions to facial dermatitis? 1, the intrinsic quality of cosmetic materials, cosmetics, preservatives, decolorants, fragrances, shading agents, sweat agents, emulsifiers, hair dyes and some heavy metal substances, are different degrees of direct stimulation of the skin or cause skin metamorphosis; some cosmetic ingredients also have photosensitivity, the use of ultraviolet radiation in the sun caused by skin photosensitivity, skin erythema or pigmentation; 2. 2, the use of outdated, contaminated cosmetics, or long-term use of pharmaceutical cosmetics containing steroid hormones, etc., can lead to folliculitis, hirsutism, vasodilation, skin atrophy and other reactions; 3, cosmetics contact with the skin or produce direct primary stimulation, or hypersensitivity reactions, some photosensitive substances into the skin can appear photosensitive reactions or phototoxic reactions. Why does facial cleanser easily lead to skin sensitivity? Most of the popular facial cleansers on the market today contain three ingredients: aromatic/fruit acid derivatives, fragrances and antiseptics. Among them, aromatic acid/fruit acid derivatives have the effect of implicit peeling (i.e. mild exfoliation), which can lead to artificial thinning of the skin stratum corneum after a period of continuous cleansing of the face for two to three times a day or even in combination with two or more facial cleansers. As a result, the function of the stratum corneum as an epidermal barrier and water-bearing layer (the stratum corneum contains about 70% of the total water content of the skin) is damaged, resulting in persistent dry skin, increased chances of bacterial and fungal infections (manifested as acne-like lesions), capillary dilation and increased sensitivity. Does cosmetic dermatitis occur in men? Although most of the people who use cosmetics are women, with the change of time, there are many men who use cosmetics, which should be noted, so the incidence of male facial dermatitis is increasing year by year. How to identify the good and bad of cosmetics? In addition to the use of allergies and photosensitivity and other direct reactions, most cosmetics do not immediately cause skin allergies; if cosmetics contain hormonal ingredients, during the use of skin will become light, tender, white, but long use will cause epidermal atrophy, capillary dilation, bacteria and fungal infections increase, and therefore the emergence of “lesions sometimes good and bad, recurring The phenomenon of “recurring lesions”. Therefore, an important aspect of identifying good and bad cosmetics is not to rely on the effect of use to explain the problem, but to rely on the changes in the skin after discontinuation of use as a basis, so that “good cosmetics do not affect after discontinuation, while bad cosmetics begin to have problems once discontinued. How do I clean my face properly? Cleansing milk or soap (without fungicides and sulfur ingredients) once every two to three days; wash your face with a very small amount of pure milk in the morning and evening.