Origination

Human skin is a sensitive organ. It reacts to hot and cold temperatures, dirt and dust, sun, stress and touch, internal factors like nutrition and events like hormonal changes and illness.

Hormones. Hormones are chemical messengers that are produced within the human body and sent through the body to initiate certain changes. They are e. g. responsible that we grow, that our heart pounds if we are excited, that boys get a beard and girls get breasts during puberty; and they have an effect on the skin.

In some phases of life, e. g. in puberty, pregnancy, menopause and during the female menstrual cycle, the quantity and the composition of the hormones in the so-called “hormonal metabolism” may change. In puberty it changes remarkably. Especially, more androgens (male hormones) are discharged, in girls as well as in boys.

These hormones cause the maturation of the sexual organs and, as a side effect, stimulate the sebaceous glands of the skin to produce more sebum than usual. At the same time, by effect of the hormones, more horny cells are produced in the excretory duct of the sebaceous glands, and they block the duct like a plug and hinder the increased amounts of sebum from draining off. Thus the sebaceous gland is clogged, the locked-in sebum making it swell.

From outside you can see these horn plugs as white or dark-coloured little domes or points. These are the so-called comedones (whiteheads and blackheads). The dark color is not dirt but results from the dark skin pigment (melanin) within the horny substance.

Bacteria. The skin of every human being is populated by many bacteria that are important to the health of the skin. Among them are the Propionibacteria acnes, a bacterium which is normally harmless on the skin surface.

If comedones develop, this bacterium lives on the increased sebum, multiplies rapidly and causes infections in the clogged sebaceous glands. These start to swell, the skin becomes red and tense, and a white or yellow point becomes visible – a spot has formed (inflammatory acne).

If the infection of the gland becomes more intense, the gland may even burst and distribute its content into the surrounding tissues. Pustules and nodules develop which may be painful and can leave scars after healing (nodulous acne).