This won't be the cause of everyone's Acne, but if you've had all blood tests for hormones, thyroid, & food intolerance come back normal and your only health problem is skin disease it might be worth googling Demodex parasites, they live on the skin and can cause all sorts of havoc including acne. Especially check this out if you are experiencing hair loss too, remember to use a natural treatment such as Tea Tree or Clove oil - (chlorinated water is good too). I read a post recently, a girl said her skin was red raw and her hair was falling out, but before I could suggest Demodex parasites to her, she had killed herself... I just wanted to put this out there to anyone willing to listen, because it could explain a lot.
This is the truth and most people neglect it because they think mites on the face are ridiculous -- but these are not science fiction.
Anybody who doesn't believe this mite exists on his/her face, check this out http://en.wikipedia.org/wiki/Demodex
Teenager acne also caused by Demodex Mites[edit source | editbeta]90% of the teenagers acne is caused by Demodex mites, 10% is bacterial,the change of the hormones at that age makes the sebaceous glands produce more sebum,making the facial skin a perfect living and breeding place, they can now easily multiply and this is translated in infections and acne.
Judging by the grammar, it's probably BS.
This is a nice testimonial for the treatment of skin disease caused by Demodex Parasites, http://www.keratosispilaris.org/treatment-options/5029-34-years-later-cured-demodex-parasite.html