A chronic dermatological condition such as acne can leave both physical and emotional scars on teens, especially in a society that values appearance so highly. Acne is the most common skin disease in the U.S., affecting more than 17 million teens and young adults. Compounding the difficulties with the problem is the tremendous amount of misinformation that still persists. Parents often are responsible for perpetuating these myths. In order to set the record straight, here are some of the most common myths you're likely to hear.

Myth 1: Acne is caused by poor hygiene. Acne does not result from dirty or surface skin oils. Some parents would have their teens believe that kids without acne are somehow cleaner. Blackheads are the remains of dead skin surfaces, not dirt.

Aggressive skin washing will in all likelihood aggravate pre-existing acne. The best approach to cleanliness is to gently wash your face twice daily with a mild soap and then pat dry before applying any of the anti-acne medications.

Myth 2: Acne is caused by diet. This is one of the oldest myths. Extensive scientific studies have not found a single connection between diet and acne. In other words, chocolate, french fries, pizza and other fast foods do not cause acne. It does make sense to limit fatty foods to prevent obesity and cardiovascular disease, however. Studies have shown that foods with a high iodine content (such as shellfish) may aggravate existing acne, but does not cause it.

Myth 3: Acne is caused by stress. The ordinary stress that teens experience on a day-to-day basis has nothing to do with acne. Ironically, many medications prescribed for stress or depression can cause acne as a side effect.

Myth 4: Acne is just a cosmetic disease and you will get scars if you keep picking. Yes, acne does affect the way people look and can result in permanent physical scars. However, squeezing blackheads rarely results in scarring. Picking and poking at acne lesions might make the lesions last longer and the temporary stain produced when a blackhead is squeezed will make you appear to have more lesions than you actually do.

Myth 5: You just have to let acne run its course. The truth is, acne can be cleared up. If the acne products you have tried haven't worked, consider seeing a dermatologist. With the products available today, there is no reason why someone has to endure acne or get acne scars.

Myth 6: Oily skin is the main cause of pimples. Acne is not caused by oily skin. It is a condition in which the cells that line the hair follicle are shed normally but fail to make it to the skin's surface to be washed away. These cells build up, mix with oil and bacteria, and form a plug. Yes, kids with acne do have oily skin, but a greasy complexion is a symptom of acne, not a cause.

Myth 7: Acne is contagious. A popular myth spread mostly by fathers to keep their teen girls away from acne-covered teen boys. Nothing you do will either cause you to "catch" acne or "give" it to someone else.

Myth 8: Don't wear makeup if you have acne. Most dermatologists feel that cosmetics — even those with an oil base — do not cause acne or worsen the condition if it already exists.

Myth 9: The stronger the medicine, the better. This is a myth most teens believe. If a 25 percent solution of topical benzoyl peroxide is working, then a 10 percent solution will work better. The truth is, if a lower dose is working well, then increasing the dose will have no effect on the acne and will only cost you more money.

Myth 10: If your parents had acne, there is a good chance you will have it too. Some families may have certain skin conditions that predispose their children to acne. Therefore, this final "myth" may be true!