Nowadays, more and more patients are complaining that their skin is sensitive and prone to allergies. According to a survey, nearly 55% of women consider themselves to have sensitive skin. Of course, this figure is inevitably somewhat ambiguous because of the lack of certain expertise, but it does reflect some of the complexities of the current situation. The symptomatology of skin allergy is always polymorphic, either simple or complex, with a helper sensation of burning, tingling, itching, coupled with objective manifestations of flaking, erythema, or even eczema in severe cases. After checking clinical studies in many aspects, we found that there are three types of allergic skin: 1. This type is defined as congenital skin sensitivity, such as atopic skin or skin with a tendency to rosacea. 2. Atopic skin is characterized by an abnormal stratum corneum, so this type of patient is more prone to itching; 3. And rosacea-prone skin is characterized by a tendency to congestion of the skin vessels once the skin receives an irritation. Skin sensitivity caused by irritants. These irritants include: 1, climatic factors: wind, cold, sunlight. 2.Environmental factors: pollution, hard water, tobacco. 3.Mechanical factors: dermabrasion, laser. 4.Drug factors: retinoids, peeling agents. This skin allergy to allergens, especially after exposure to beauty and skin care products containing preservatives and fragrances. Idiopathic skin sensitization. This type of sensitivity has no etiological basis and patients always report that their skin cannot tolerate any cosmetic skin care products. It seems that skin sensitization is currently on the rise, so for dermatologists, the root cause of sensitive skin needs to be addressed.