As the seasons change, it’s autumn again, the climate becomes cool and dry, the trees are dying, the fruits are tired, and the animals are accumulating fat to cope with the cold winter. As a part of the natural world, our bodies are changing accordingly, and our skin is prone to dryness. Every year in autumn, we can see a significant increase in the number of skin diseases related to dry skin (such as pruritus, atopic dermatitis, allergic dermatitis, etc.) in our dermatology department. Why is this? And what can we do to protect our skin health? From the perspective of traditional Chinese medicine, autumn is the season of “dryness”, and to keep our skin healthy, we need to fight against this “dryness”. So what is dryness? According to Chinese medicine, there are four substances in the human body: “qi, blood, fluid”, of which “fluid” plays the role of nourishing the limbs, claws and nails, organs, bones and muscles, just like water in nature nourishes everything. And “dryness” is the evil qi that damages fluids and causes a series of dryness signs, which is called “dryness is dry” in Chinese medicine. Just like the need for irrigation when water is scarce, our body needs nourishment in autumn when it is dry. We all have the common sense that we need to drink more water in autumn and eat some fruits rich in water to relieve the discomfort of dry mouth, dry throat and dry skin. But there are some people who do not drink less water and eat less fruit, but still have obvious dryness symptoms, why is this? This leads to another problem, “lung spleen qi deficiency”. According to the theory of Chinese medicine, the heaven and man correspond to each other. The lungs have the role of transporting and dispersing fluid, while the spleen’s role is to transport and absorb water and grain essence. In layman’s terms, the role of the spleen is to transform the diet we consume into essential substances such as qi, blood and fluids, while the lungs are the “porters” that transport the fluids to all parts of the body. There are differences in people’s constitution, and some people may have poor lung and spleen function, or the function of the internal organs may be declining with age, or the lung and spleen function may be damaged for one reason or another, which is why the phenomenon of “food therapy is not working” may occur. This is also in line with what we see in the clinic in the autumn pruritus is more common in the elderly, patients with physical weakness and patients with inherently dry skin. Common symptoms of lung and spleen qi deficiency include coughing and wheezing, shortage of breath, thin white phlegm, loss of appetite, abdominal distension, loose stools, low voice and lazy speech, white and lusterless face, or puffy face, pale tongue with white fur and weak pulse. If these manifestations are present and the dry skin of the mouth and nose is difficult to relieve in autumn, it is necessary to seek medical help in the hospital. The symptoms can be controlled and relieved through dietary therapy, Chinese herbal soup and topical medication according to the patient’s specific condition under the doctor’s advice. Under the effect of “dryness”, it will not only bring people dry discomfort, but also lead to the occurrence or further aggravation of some skin diseases. Modern medical research proves that skin with poor water content has poorer resistance and is more prone to various skin diseases such as: Pruritus: Patients will have itching sensation all over the body, but not all over the body at the same time, often moving from one place to another, without a typical rash but with obvious dry skin symptoms, more common in the elderly. Atopic dermatitis: This is an allergic skin disease with a certain genetic predisposition, which has different skin manifestations in infancy, childhood and adulthood, but all have a common feature of dry skin. Chronic eczema: The lesions manifest themselves in a variety of ways, with significant itching and lesions that can appear like dried bark on various parts of the body. For these problems, in addition to dietary therapy and internal medication, another very important method is to use moisturizing cosmetics. In recent years, thanks to technological advances, there is a wider choice of moisturizers. By simulating the mechanism of the skin’s natural moisturizing system to promote transcutaneous water absorption, increase epidermal water content, help restore skin barrier function, reduce dry skin, flaking, and make rough skin smooth and soft is the purpose of many cosmetic research. Depending on the added ingredients moisturizers can be broadly divided into natural moisturizers and chemical synthetic moisturizers. Among them, natural moisturizers include the body’s inherent ingredients such as hyaluronic acid, neurophenolamine, glycerin, and also from plants and animals or their extracts such as honey, ganoderma lucidum extract, aloe vera extract, ginseng extract, etc. Chemical synthetic moisturizers include lactic acid, polyols, and their derivatives, polyacrylic acid resin and other chemical synthetics, and the oil and water in the cosmetic matrix itself also play a role in skin moisturization. Although most moisturizers boast that they are “natural” and “safe”, it should be said that no cosmetic product is absolutely safe for different skin types, and consumers have to choose according to their own skin sensitivity. In short, in the “autumn dryness” environment, external moisturizers, reasonable diet, combined with medication if necessary with the help of a doctor, both internal and external is a good way to maintain healthy skin.