Tobacco can cause acne?

Mostly no: Smoking generally does not affect acne, though it does cause early aging. However, there is some controversy, as there is in much of medicine. There is some research that shows smokers have less acne than nonsmokers (http://www.Ncbi.Nlm.Nih.Gov/pubmed/16645586), and some that shows worsening of a certain type of acne in adults who smoke (not teens) (http://www.Ncbi.Nlm.Nih.Gov/pubmed/20619486).

Yes: Smoking usually dries the skin and increases the likelihood of skin looking more aged and wrinkled, but in many people with acne, smoking results in a worsening. There is nothing about smoking that is good for you, and if it takes getting worse acne to get you to stop, then that at least is one good thing. It causes cancer, emphysema/bronchitis and premature heart disease as well as skin effects.