WaR UndeR THe SKin (Pimples)

They can be compared to an erupting volcano. Or, even better, to a battlefield. And it is this fight that provokes the explosion of the "crater".
It all begins with the infection of a blackhead, that is, a black spot. On our skin live in fact some usually harmless bacteria like Propionibacterium acnes and Staphylococcus epidermidis . They can penetrate inside the blocked pores from the black spots and cause the eruption of the boils. The bacteria pass through the pore and descend into the follicle where the hair-growing cells and those that produce sebum: the oily substance that protects them.

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WAR UNDER THE SKIN

This infection immediately recalls the body's defenses. White blood cells and antibodies rush from the blood vessels and the surrounding dermis (the tissue beneath the epidermis). The whole area swells up: the furuncle is born. It is red because the capillaries dilate to favor the influx of "defenders", which usually destroy bacteria within 24-48 hours or more. It is a battle without the exclusion of blows, which also involves the innocent: the white blood cells in fact emit enzymes capable of destroying the outer membrane of bacteria. But enzymes make no distinction, and they also break down the wall of the surrounding cells, those that make up the follicle. That's why, when the boils are many and deep (as in cases of severe acne), they can remain scars. Toward the end of the battle, then, macrophages arise from the blood, specialized cells that make a clean sweep of the remains of the dead fighters.

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WHAT IS THE YELLOW LIQUID?

At this point the pimple is full of a yellow liquid, made of water, a little sebum, antibodies and "defeated" bacteria, which can make its way to the surface and get out of the pore. The infection is won. The pimple healed. Slowly the redness also decreases: the capillaries tighten and return to normal size.

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HORMONES IN THE FIELD

Therefore, for there to be a furuncle, at least one black spot must exist on the skin. How is it formed? It is a kind of "chain reaction", which occurs mainly during adolescence, but which is also the basis for the formation of boils in adults. Androgens (sex hormones) stimulate the sebaceous glands, which are attached to each of the hairs of the epidermis, to produce more sebum.

OUTPUT BLOCKED

The skin becomes shiny, fat, and reacts by becoming thicker: this causes the pore to close. The gland continues to work, but the sebum no longer comes out: within a few days the black spot is formed. In reality nobody knows why the skin reacts to the massive production of sebum becoming thick. We can only try to prevent it. Today, in fact, the problem can be solved by preventing the formation of comedones with retinoic acid(Retinoids), a substance that prevents the epidermis from thickening too much. This is indeed the true cause of acne: bacterial infection is only a consequence.

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IT'S RED? DO NOT SQUEEZE IT

Do you need to crush the boils? Only if they have the little yellow tip in relief on the surrounding swelling: it means that by now the immune system has done its job to the end and you can let out the liquid. Just stretch and then press the skin around a bit. If instead the pimple is still only red, crushing can even be harmful: the liquid can not come out because the swelling has tightened the channel that leads to the pore and, pressing the area with the fingers, the inner walls of the follicle can break, propagating the infection to the surrounding dermis, with the result of increasing the diameter of the pimple and therefore the risk of scarring. Crushing the blackheads instead serves to prevent them from turning into boils.

Do fries and chocolate make pimples come?
False: acne is mainly determined by hormones, and therefore depends on predisposition and age. On the contrary, it is true that an excess of fried foods and sweets hurts the skin.

WHY DO WE LIKE TO CRUSH THEM?

When a pimple comes up, it's normal to try and eliminate it. It is done to remove an unsightly element from the face but also to relieve anxiety and boredom. Teasing the skin, both of the face and the body, is a behavior experienced by all but for some people can turn into a disease: there are those who feel the unstoppable need to crush boils and pimples. By getting injured in serious way and negatively affect their social relationships.
These people suffer from dermatillomania, an obsessive compulsive disorder that entered the latest edition of the Diagnostic and Statistical Manual of Mental Disorders. According to the studies, dermatillomania affects from 1% to 3% of the world population, even if psychologists believe that it is an underestimated value. Often those who are affected also torment their hair and nails.

THE PIMPLES-FREE

Acne, however, is not for everyone: there are people who go through adolescence without a pimple, skin as smooth as silk, and others who have to fight with them all their lives. The explanation is simple: it depends on the number and the functioning of the receptors for the hormones that each of us has on the sebaceous glands. Some people are born with glands with many receptors: at puberty they will start to work and, receiving more hormones, will produce more sebum, then comedones and boils. Others have less receptors and therefore smooth skin. It is no coincidence that there are populations that almost never have pimples, like the Japanese and Koreans: in their glands, few receptors.

Big Thanks to @syndicates for this cool Badge