If pimples and acne scars on the face are bothering you try putting some garlic juice or a mud pack. Or if you are game for medical help laser treatment and chemical peels are an alternative say dermatologists. The acne problem usually starts around the age of 10-13. Though many get rid of it by their 20s for some it lingers. 'In teenagers there are two things that trigger acne problem. First is hormonal changes in their body. In boys it is the increased secretion of testosterone and in girls the levels of both testosterone and oestrogen rises' Chytra V.