”Sensitive skin” is a term often mentioned by the general public, especially women, and there has been a lot of controversy in academia questioning the validity of this concept. What is the definition of sensitive skin? The concept of “sensitive skin” originally originated with consumers and manufacturers of skin care products and cosmetics. Surveys show that approximately 40% of people consider themselves to have sensitive skin, and a higher percentage of women than men complain of sensitive skin. These skin sensitizers are often seen for discomfort such as tingling, burning, itching or tightness after using certain skin care or cosmetic products, but the clinical signs are very mild. It is clear that sensitive skin is a term used by people who often feel that their skin is intolerant or more reactive than the general population, and the term “self-perceived sensitive skin” is considered more relevant and objective in academic circles. Sensitive skin is characterized by subjective sensations and symptoms, such as tingling, burning, itching, and tightness after the skin has been stimulated by different physical and chemical factors, and these uncomfortable sensations usually appear immediately after the skin has been stimulated and last for minutes, hours, or even days. The intensity of the sensation can vary greatly from individual to individual, with severe cases being unable to tolerate almost any skin care products. Sensitive skin is most often seen in younger women and decreases with age. Symptoms of sensitive skin are not continuous and are often triggered by specific environmental factors or exposures such as wind, sunlight, changes in temperature and humidity, hard water, cosmetics, stress, spicy foods, and menstruation. Why does skin become sensitive? The causes of sensitive skin are not known and may be the combined result of multiple factors such as endogenous and exogenous factors acting separately or together. Most people with sensitive skin are related to individual qualities. Caucasians and those with cheek skin prone to flushing are more likely to have sensitive skin, and both severe dry skin and severe oily skin can show signs of skin sensitivity. 2, certain diseases can cause increased skin sensitivity, such as atopic dermatitis, eczema, rosacea, irritant dermatitis, etc. The study found that 66% of female atopic dermatitis patients are sensitive skin, and some patients in the subclinical stage of dermatitis, although no typical clinical manifestations, but increased skin sensitivity. 3.Sometimes some topical medications (such as those containing salicylic acid, retinoic acid or hydroxy acids) and cosmetic skin laser treatments, fruit acid peeling treatments, etc. can also cause temporary skin sensitivity. 4, from a microscopic level, all causes of sensitive skin are related to the destruction of the skin’s stratum corneum barrier. When the stratum corneum is incomplete, the moisture in the skin is more easily lost, and various external irritants are more likely to enter the skin to stimulate the skin’s immune cells or nerve endings, resulting in dryness, tightness, tingling and other uncomfortable symptoms. Are sensitive skin and skin allergies the same thing? From the definition of sensitive skin and its causes, many causes, including various inflammatory skin diseases, can cause temporary or long-term skin sensitivity, while skin allergy (more scientifically known as “allergic contact dermatitis”) is an immune reaction to the skin caused by exposure to a specific allergen. When the allergen is removed, the dermatitis will gradually improve and heal. Of course, after the skin allergy (allergic contact dermatitis) is healed, skin sensitivity will also appear and last for a while. How to treat sensitive skin? The treatment of sensitive skin can be a challenge for dermatologists. Patients often come to the clinic with many skin care products, expecting the dermatologist to improve the skin’s discomfort, as well as provide advice on skin care and cosmetic use. Although there is no universally accepted treatment or principles for sensitive skin, the following recommendations from scholars are helpful in helping patients improve their symptoms 1. Stop using all topical skin care products, over-the-counter therapeutic medications, skin care, cleansing and cosmetic products for 2 weeks, during which time mild soap-free cleansing soaps and mild medical moisturizers can be used. 2. Stop using all topical medications for 2 weeks, especially those containing benzoyl peroxide, retinoic acid, hydroxyacetic acid, volatile alcohol or other medications that may cause skin dryness or irritation. 3. Eliminate all causes of skin friction or irritation within 2 weeks, wear loose, soft-textured clothing, and reduce skin friction caused by exercise. 4. Evaluate after 2 weeks to detect underlying skin conditions such as seborrheic dermatitis, eczema, psoriasis, acne, rosacea, and perioral dermatitis in patients, or determine the presence of contact allergens (usually derived from skin care products) by skin patch testing. If the patient has any of these skin conditions, treat with appropriate medication for at least 2 weeks or until the lesions are completely healed. How do I choose skin care products for sensitive skin? Sensitive skin has high requirements in terms of skin care and cosmetic use, and should try to choose medical skin care products without added fragrances, and can refer to the following principles: 1, if necessary, only one additional skin care or cosmetic product per week, try to choose a softer nature, single ingredient and designed for sensitive skin manufacturing products, the order of increase for lip balm, foundation and blush. 2, other cosmetic products that are likely to cause discomfort in people with sensitive skin should be tested separately before use, by applying the product to be tested within 2cm of the outer eye (temporal) every night for 5 days. The order of testing is mascara, eyeliner, eyebrow pencil, eye shadow, basic facial care products and other facial cosmetics with color. 3, some over-the-counter treatment products that remain on the face for a long time and various skin care products should be tested for excitatory application before use, in the same way as above. 4, some skin care products that rinse off soon after use should be tried once a night for 5 consecutive days before use in accordance with the methods recommended in the product instructions.