Hi. Greetings. Please note : Acne is becoming a common problem of concern in young adults too. Reduce intake of chocolates, milk and junk food too. Use a topical retinoid cream daily night. You may need a short course of antibiotics.Pimples may often leave spots especially of not treated or if we burst pimples or pick them. You'll need skin lightening creams for a specified duration to reduce the marks , and this could also be dealt with chemical peeling. Even use of a benzoyl peroxide based body wash for back and hands will be good. Send in your pictures if you need further assistance. Or see a dermatologist near you and discuss the same with him. If other modalities fail, You'll definitely benefit with oral retinoids. Hope this helps. Warm regards. Dr Govind Suresh Mittal, excel care hospital, Bangalore.