If you are certain the skin lesions are acne then you can use Benzoyl peroxide
5% lotion/cream/gel or salicylic acid
cream + oral antibiotics
such as erythromycin or cloxacillin till lesions disappear. Avoid taking antibiotics for too long. If no improvement, it means it is probably not acne lesions, then you'll need to see a dermatologist
or your doctor for further management.