I don't know if it's my delusion, I always feel that this winter seems to be extraordinarily long, seeing that February has passed more than half, but the temperature has not risen, taro has to silently wrap his little padded jacket every day at work, think about it since the beginning of winter, taro has heard a lot of skin problems that everyone is more troubled by——

I always feel that all kinds of small dry lines and fine lines on the skin are obvious in winter!

As soon as the weather warms up a little, what should I do if my face starts to break out again?

When I go out and blow the wind, my face is itchy and red, what's going on?

What should I do if my skin is too dry, no matter how moisturizing it is?

Taro took a look and suddenly realized that although it seems that everyone's skin problems are different, if you want to solve these problems, it will eventually come down to one point, that is, the skin barrier is damaged!

The term "skin barrier" seems to come up a lot in a variety of skincare issues, but what exactly is it and how important is it? Today, Taro will take a good look at it for everyone!

Microecological barriers

The microbial barrier is the outermost layer of the skin barrier, which is made up of different microbial communities that cover almost all of the skin's surface areas.

These microbial communities are composed of bacteria, fungi, viruses, etc., and they have a variety of communication channels with each other, and under normal skin conditions, they balance each other, maintain a relatively stable relationship, and also maintain the homeostasis of the microbial barrier.

Chemical barriers

Compared to the rest of the skin barrier, the definition of the chemical barrier seems to be less clear, mainly because it is so closely related to the physical barrier.

In general, the chemical barrier contains various factors that affect the pH level of the skin's surface, as well as compounds that make up the "natural moisturizing factor" (NMF), such as sebum, sweat, and related substances broken down from intercellular lipids, which maintain the weak acidity of the epidermal environment while also moisturizing the skin to a certain extent and prevent excessive dryness.

Physical barriers

The third physical barrier is the stratum corneum, which is actually the result of the maturation of keratinocytes.

Keratinocytes are very active throughout their lives, and from the moment they are born in the deep layers of the skin, they try to slowly move through the epidermis to the surface of the skin, growing and maturing as they move.

By the time they are close to or have moved to the surface of their skin, their lives are almost over. But this is not the end, as dead keratinocytes are still burdened by squashing, enucleated, and the cell membrane is replaced by an envelope, eventually forming a neatly arranged, tightly packed layer of "bricks" of granules.

Although these keratinocytes have worked hard to make each other more compact when arranging, there are actually gaps, and in order to fill these gaps and make the skin firmer, many important protein particles "come forward", such as filasilin, permethrin, keratin filaments, and lipid layers, etc., these contents are like "cement" to fill the intercellular space of the stratum corneum, which is what we call "intercellular lipids". So in general, the stratum corneum is composed of dead keratinocytes and intercellular lipids.

Immune barrier

The last part of the skin barrier is the immune barrier, which is mainly composed of a variety of immune cells distributed in the epidermis and dermis, such as a variety of resident antigen-presenting cells, natural lymphoid cells, native like cells, keratinocytes, adaptive tissue resident memory cells, etc.

These immune cells are like the skin's own "sentinels", which can effectively sense the danger signals sent by microorganisms through pathogens and damage-related molecular patterns (that is, the relevant molecules triggered by skin damage), and activate the corresponding immune response to defeat external stimuli that invade the body. In short, their "team" has only one goal, and that is to maintain the integrity of the skin barrier.

So here's the problem-

What is the skin barrier that we usually refer to?

The answer is: neither!

When we talk about the skin barrier, we generally refer to the "skin barrier" in a narrow sense, which is composed of sebaceous film and stratum corneum. We all know about the stratum corneum, and the physical barrier in a broad sense is it. As for the sebaceous film, it is usually made up of sebaceous gland cells, keratinocytes, and the skin microbiome.

So, to put it simply, we can think of the narrow "skin barrier" as a "combination" of the physical barrier and the chemical barrier, but in fact, it also involves the superficial microbial barrier and the deeper immune barrier.

Let's take a look at the relationship between the sebaceous film and the stratum corneum separately, but they are actually very interesting. If the "sebaceous film" is compared to the "moat" that protects the skin, then the keratinocytes and intercellular stroma in the "stratum corneum" are the solid "protective walls", and the combination of the two can not only prevent pathogens, pollutants and other irritants from entering the body, but also lock in moisture and maintain the skin's water and oil balance.

Therefore, once there is a problem with the "protective wall" or "moat", the skin is in danger, dryness, scaling, redness, itching, stinging, etc. are the basic reactions, and the germs on the surface of the skin enter the skin through the damaged barrier, causing a series of skin inflammation is really troublesome! Recurring acne and stubborn "backlight rash" are likely to be signs of a damaged skin barrier!

The seemingly strong skin barrier is sometimes really delicate, and if you are not careful, you may step on the "pit" that hurts it, and probably it also wants to shout "Why am I always the one who hurts"!

Reason 1: Improper cleaning

Basic skin cleansing can hide potential damage to the skin barrier, and the wrong way to cleanse can be divided into two situations: over-cleansing and under-cleansing.

In contrast, it is easier for us to be caught by over-cleaning, such as using cleaning products that are too aggressive or too frequent, and frequently using scrub particles, salicylic acid, and fruit acid products for exfoliation, all of which fall into the category of "over-cleansing".

Excessive cleansing will not only destroy the sebaceous film, but also cause the loss of ceramides, free fatty acids and cholesterol factors in the interstitium of cells, reduce the skin's ability to retain water, and without sufficient moisture support, various physiological functions of the skin will be affected, thus causing various skin problems.

Reason 2: Overhydration

Lack of moisture can cause a range of skin problems, and overhydration can also be harmful to the skin barrier.

According to experiments, the more hydrated the skin, the more it may become more permeable to irritants and allergens, making it less tolerant and therefore more sensitive.

Reason 3: Long-term, frequent use of skin care products containing irritating ingredients

As we all know, in many cases, the greater the "ability" of skin care ingredients, the greater the temper, such as the well-known anti-aging expert retinol, and the acid ingredients that can exfoliate and make the skin more delicate, although their efficacy is strong, but the irritation cannot be ignored.

Coupled with the fact that everyone's skin has a different tolerance, long-term and frequent use of these skin care products containing highly irritating ingredients will inevitably cause damage to the skin barrier and cause a series of skin problems.

Reason 4: No sun protection or inadequate sun protection

The importance of sunscreen to the skin does not need to be emphasized again by taro, sunscreen is actually to reduce the adverse effects of sunburn, sunburn, photoaging and other adverse effects that may be caused by ultraviolet rays as much as possible without affecting the beneficial effects of ultraviolet rays, so if you do not protect from the sun or the sun protection is not in place, the skin barrier will be damaged.

For our common problem of damaged skin barrier, by filling the "cement" between the "brick wall", that is, supplementing lipid components such as ceramides, free fatty acids, cholesterol, etc., we can better promote barrier repair and enhance the skin's water-locking function.