Hello, Hormonal imbalance is an important cause of persistent acne beyond age 25 or adult onset acne. To diagnose any underlying cause you will need to undergo a few blood tests and evaluation. I would recommend you to visit a dermatologist for the same. Avoid touching, scratching, picking pimples, using scrubs or rubbing vigorously with towels as all these activities impair with normal healing process and cause dark spots or scars. Use skin care products which are labelled as non comedogenic. Avoid oiling of hair as it may further clog your pores. Restrict dairy products,have lots of fruits and vegetables in your diet and maintain healthy lifestyle by daily exercise. You can visit www.eternisclinic.com/dermatology/ to know more about acne and for skin care tips. Warm regards, Dr Pinanky Jadhav, Pune