Most of the cosmetics currently on the market are suitable for all skin types, including “sensitive skin”. They are rigorously tested to determine that they are non-allergenic and non-comedogenic before being marketed. Sensitive skin” refers to a very small number of people whose skin is susceptible to reactions to irritants, allergens and other environmental factors, and is a synonym for “skin allergy,” a term currently used only by the cosmetics industry. The causes of sensitive skin are complex and can be broadly divided into two categories: internal (genetics, diet, stress) and external (climate, pollution, chemicals, decontaminants). If a very small number of people with genetically sensitive skin use cosmetics in a hypersensitive state (e.g., on top of allergies caused by eating seafood), they are very susceptible to cosmetic contact dermatitis and aggravation of the existing disease. How to determine cosmetic contact dermatitis? 1, irritant contact dermatitis There is a clear history of cosmetic contact and dermatitis changes sooner after contact; lesions are confined to the contact area, clearly defined; under the same conditions, generally more exposed people develop; there are varying degrees of papules, edema, water scars, rupture can be vesicles, ooze, crust. Self-perceived local lesions are itchy, burning or painful. 2. Allergic contact dermatitis has a clear history of using or repeatedly using cosmetics, and has a certain latent period; only a few people generally develop the disease among those who use the same cosmetics; the primary site is confined to the contact site, but can spread to the surrounding or distant parts; the lesions have various forms, with self-conscious itching, and can be manifested as dermatitis, erythema scales, head and facial redness, periocular inflammation with conjunctivitis, palms and The lesions are often prolonged, and the patch test is often positive. Other non-cosmetic contact factors are excluded (e.g. contact dermatitis due to contact with paint, rubber, etc.). The use of cosmetics can also cause cosmetic acne, cosmetic photosensitive dermatitis, and cosmetic skin pigmentation abnormalities. The formation of cosmetic acne with good quality cosmetics is mainly related to the improper selection of cosmetics, such as oily skin candidates using cosmetics with oil-in-water preparations (more powder and petroleum jelly ingredients) can lead to impaired sebum excretion and the formation of blackheads and inflammatory papules, or secondary infection and pus scars. The problem is easily cured by discontinuing the use of the suspected cosmetics and by anti-inflammatory and antiseptic treatment. Regardless of what kind of cosmetics are used in contact dermatitis, first of all, you should immediately stop using all suspicious cosmetics, promptly remove the residual cosmetics on the skin, promptly go to the skin specialist according to the principles of treatment of dermatitis – eczema symptomatic treatment, after active treatment, generally 1 -The eczema can be cured within 2 weeks. If the cause of the disease is not detected in time, and at the same time use other types of cosmetics, cross-allergy, multivalent allergy, dermatitis is easy to recur, or into chronic, prolonged. Therefore, when cosmetic contact dermatitis is suspected, the use of all types of cosmetics should be stopped in order to facilitate diagnosis and treatment.