Hello, This is Dr. Papaqako answering your question. Stretch marks happen when the skin is pulled by rapid growth or stretching. Although the skin is usually fairly elastic, when it s overstretched, the normal production of collagen (the major protein that makes up the connective tissue in your skin) is disrupted. As a result, scars called stretch marks may form. Stretch marks happen because of the changes in weight, and almost every woman may have those. The truth is that stretch marks can t go away entirely without the help of a dermatologist (a doctor who specializes in treating skin problems) or plastic surgeon. These doctors may use one of many types of treatments — from actual surgery to techniques such as microdermabrasion and laser treatment — that reduce the appearance of stretch marks. The pimple is most probably an infected hair follicle, that if is the only lesion you have, will heal itself without the need of any particular treatment. Hope this helps, Take care.