1. Stress causes acne
Stress has a minimal influence on a persons ability to develop acne through stress. Stress doesn't cause acne, but it can influence the re-occurrence of acne as stress levels increase the body's creation of a substance called cortisol.
Cortisol causes the sebaceous glands in the skin to produce increased amounts of sebum oil which ultimately blocks the pores.

2. Acne is contagious
No one can "catch" acne; it is non-communicable.

3.You'll outgrow acne, so just leave it along and it will heal itself.
Acne strikes all ages and is treatable, but shouldn't be left alone to worsen. (It should be treated so it doesn't cause scarring)

4. Being out in the sun helps acne
The sun may appear to help clear up blemishes and redden the skin, thus lessening the overall effect. However, rays from the sun cause skin damage and irritate and worsen existing acne problems clogging more pores as skin cells dry up and slough off quicker than normal. So use caution (and sunscreen).

5. Sweating helps clean out your hair follicle areas
Strenuous activity can temporarily increase your body's oil production which can worsen acne problem areas, causing recurrence or intensification.

6. Acne problems are directly proportionate to sexual activity, (Too much or not enough depending on your point of view)
Just because teenagers are going through hormonal changes, doesn't mean it has anything to do with acne. Both are separate issues. Same with adult acne and sex; (These are also two entirely different issues.)

7. People with acne are dirty and don't wash enough.
Acne is the result of a build up of oil, dead skin cells and bacteria in a closed pore. Dirt isn't even a factor

8. Acne is only an external issue or surface deep so people shouldn't make such a big thing out of it,
In reality, yes, it basically is only on your skin (and underneath the surface a little bit). However effects of acne run much deeper. More than 50 percent of those suffering acne report negative comments from members of society, regardless of whether or not there was any scarring left for others to see afterwards. This can result in depression and low self-esteem which is harmful not only short-term but over a person's lifetime.

9. There is a cure for acne
Although there is no cure, there are many treatments available that do a great job. Prevention is the best medicine;" and there is no need to suffer in silence with all the options available on the market today.

10.If you suffer with acne you should not use moisturizers or other make-up products on your face
Today there are many noncomedogenic cosmetics out there specially formulated to NOT clog your pores.

About the Author
Kim is a Registered Nurse working for a large Hospital Trust in the UK,

She can be found at http://www.acne-and-you.com and http://www.nursing-hints.com