The causes of acne are complex and probably stem from a genetic predisposition towards this type of skin along with a hormonal component.
I think the best way to address this question is to rephrase it as "What does not cause acne?" as we know that better than we know what does cause Acne.
What doesn't cause Acne allows us to dispel the myths and perhaps save you money for products that prey off your desire to have clear skin.
- Acne is not related to chocolate or fried foods.
- Acne is not related to having "dirty" skin.
- Acne is not related to "improper" thoughts
Acne "Flares" (ie not the cause of the condition just exacerbators) probably are related to:
- hormonal changes, menstrual irregularities
- excessive picking at acne lesions
It is National Acne Awareness, which follows the much more significant skin cancer awreness month. I say this since most people who have acne are all too aware that they have it, while, unfortunately, there are many people harboring skin cancers that do not realize it. Who thought of this month anyway? Was it to make sure that those with acne felt even more "picked" on?
There is not a single cause and this accounts for the various apperances acne may assume.
Most acne is driven by hormones. There is an excess, or an excessive sensitivity to the male hormones, the androgens. This causes increased sebum ( oil) production. At the same time, there is a problem in the follicle. The cells in the follicular wall are sticking together too much. Plus they are overproducing. The follicle wall, which should be a thin, tender structure, has become thickened. widened and now plugs up the opening. The skin bacteria, P. Acnes, which resides in this area, begins to breed wildly as a there is now a perfect microaerophilic ( small amount of air) in the follicular canal. The bacteria commences to munch on the sebum. Part of sebum consists of triglycerides. The bacteria secretes lipases, an enzyme which splits the tri (three) glycerides ( fat) into three fatty acids. Fatty acids are very irritating to the follicule and the body's white cells are summoned. The white cells begins to attack and releases peroxidases and proteases. The follicular canal is now breeding a malicious swamp of consistuents, any one of which, alone would mount no problem. and in fact, would usually be helpful, i.e. normal bacteria flora ( which helps prevent the unwanted intrusion of dangerous bacteria such as staph aureus), sebum ( coats the skin, keeping it moisturized), and white cells, the Lord Protector of our immune system.
As long as there was only plugging of the skin, we had either a whitehead or closed comedone, if the follicule opening had been lost; or a blackhead, or open comedone, if the follicle opening had been maintained. When the follicle becomes even fuller a papule forms. Early white cell invasion causes an inflamed papule. Further white cell involvement with release of its constituents. including pus, forms a pustule.
Gradually, the follicle wall weakens, when it bursts the cystic phase of acne is reached. As long as the contents remain in the follicular canal, there is no scarring. However, once these contents break out , the body tries to wall them off. A means of doing so, is the construction of a scar.
I hope I have answered your question. Please realize that I have summarized volumes of papers and books in a few short (for me) paragraphs.