Acne usually has internal causes, HELICOBACTER PYLORI in the intestines and suchlike. For a long time I believed, I had observed a causality between pimples and diving or using makeup before TV interviews. One day I got angina and was treated with antibiotics. Lo and behold, in three days angina was gone and all pimples were gone, too! For several years I had a severe acne problem and basically got rid of it with a course of antibiotics and applying Finacea gel on the problematic areas. Fresh pimples had to be disinfected with a special lotion of alcohol, levomycetin and some other ingredients. I also had to stop washing my face with soap and water and use cleansing solutions like Bioderma instead. A month or two of careful routine and the problem was solved. No pimples after diving or makeup, too. However, one shouldn't do it on her/his own. Consulting a dermatologist is a good idea.