The causes of skin problems are also extremely numerous. They can be of genetic, hormonal (acne) origin, due to allergies (food, drug or contact), caused by infectious diseases or by irritation.

It is difficult to make a complete list of the various skin problems as they are numerous. It is nevertheless possible to mention the most frequent: acne, eczema, herpes, etc.

Blackheads, also called "open comedones," are formed mainly on the face at the nose, but also on the rest of the T-zone, namely the forehead and chin. They are due to an obstruction of the pillar canal by keratinocytes  (a mixture of sebum and dead cells). These keratinocytes must desquamate every day, but at the time of hormonal changes or in case of bad hygiene of the skin, this desquamation does not necessarily take place well. The dead cells will then oxidize in contact with the air and block the canal, showing comedones. If they are not processed, they will evolve to white points and then buttons.

-  Puberty and  hormonal changes. The production or taking of hormones (pill) activate the sebaceous glands responsible for the production of sebum and may favor the appearance of blackheads. 

- The use of so-called comedogenic cosmetics. It is often fatty substances or occlusive makeup products that clog the pores of the skin. 

-  Poor skin hygiene and too high a diet of fats or sugars. 

-  Fat or mixed skins are more affected by blackheads. The pores are much more dilated and produce more sebum than dry skin.

Acne is a skin disease whose scientific definition is an inflammatory disease of the pilosebaceous follicle.

The pilosebaceous follicle is the association of the hair (hair follicle) and the sebaceous gland that is responsible for the production of sebum. The sebaceous gland is attached to a hair that is more or less large according to the part of the body where it is. For example, on the cheeks, the hair is very thin: its follicle is about 2 mm below the surface of the skin. The sebaceous gland is more voluminous. On the wings of the nose, the chin and the cheekbones, the hair very small, almost invisible, on the other hand, the sebaceous gland is enormous.

Concretely, no one has been able to prove anything about the exact causes of acne. Some think it's genetic, while others say the main cause is stress. It could also be linked to diet, pollution, cigarette smoking, or quality of life. Nothing is certain. However, the first element that can be considered is hormones, since acne often appears at the puberty stage. This period generates hyper-production of called sebum, hyper-seborrhea. Testosterone, produced by girls and boys, is transformed into the sebaceous glands by the intervention of a 5 to 20 times more active enzyme in adolescence. So, 80-90% of adolescents are affected.

Redness in the face is one of those little details of everyday life that some would like to do without because they can quickly become a complex and take on a disproportionate place. Skins that are particularly fragile may have sensations of overheating and redness. Over time, they may be more persistent, to the point where they settle ... and do not disappear.

- Transient flushes 

- Diffuse but permanent redness. This is called erythrosin, most commonly localized on the cheeks. 

- Small vessels, that is to say,  coupe rose, which corresponds to an aggravation of the erythrosin. 

- Red (sometimes "white-headed" ). It can be an  inflammatory rosacea

- External factors, such as the  cold or  the  sun  that cause  acceleration of cutaneous microcirculation

- Internal factors such as  emotions, drinking coffee or spices 

- Heredity: rash may occur in people with Vaso-reactive skin, a skin characteristic that may be familiar 

-  Skin aging: from 25 years the skin is more sensitive to redness.