hi kasturi you haven t mentioned you age as for certain ages the acne is very common like teenagers and young ages. it is mainly caused by the obstruction of the sebaceous glands and a bacteria is responsible for it which means it is an infection. the ducts are obstructed by the fatty acids so to control pimples you have to follow a generalized management which is of course a long term management. which includes control of diet that is consumption of low fatty diet and low spicy and oily diets. increase intake of fluids with fresh fruit juices and citric juices. use topical isotretenoin cream twice a day along with low dose erythromycin for 3 months. and after applying the cream wash your face after 30 minutes and apply your regular moisturizer. hope this will help thanks Dr.ishfaq