The first step in the development of acne is the formation of a horn narrowing or "stopper" in sebaceous gland opening, called a mikrokomedon. This leads to the retention of sebum and sebaceous gland. Blocked exit times (comedones) can be seen as black dots (blackheads) or as small bumps in the skin. The inflammation of the glands caused by normal penetrates into the sebaceous glands and breaks down the suet, and that the degradation products of this process come out of the tissue around the sebaceous gland. Degradation products activate the immune system. In this way there arises from an inflammation, possibly with formation of pus that can clear up the skin's surface.
In some cases, acne can be triggered or exacerbated, by the sun, called Mallorca acne or acne summer. Acne can also be triggered by greasy face creams (cosmetic acne), by contact with hydrocarbons (this can be an example. Look at the thighs of asphalt workers), or using certain medications such as cortisone (steroid acne) or anticonvulsants such as barbiturates or hydantoins. It is possible that excessive intake of milk may increase the tendency for acne. Otherwise, studies show that diet is important in acne. Acne is not caused by filth and is not contagious, either from person to person or from the skin site to skin a site. Stress and unhappiness seem to aggravate acne in some patients.