Hi there,
A clinical examination is necessary for correct diagnosis and management of your symptoms. If it is only on one side of face the possibilities could be dermatitis, allergies or acne. It is though unusual for acne to be on one side of face. Acne occurs due to a blockage of oil underneath the skin and builds up with bacteria causing inflammation and develops into a pimple. The common causes of acne are poor diet, stress, genetic, dirt, hormonal imbalances, cosmetics, work-related and drugs. Wash your face with mild soap many times a day. Avoid popping or scratching them. Drink plenty of water. Take good sleep.Benzoyl peroxide is very effective for acne. The vitamins which are important for healthy skin are vitamins A, B,C and Vitamin A is an antioxidant and helps keep pores clean. Vitamin B helps improve blood circulation. It helps to detoxify and get rid of impurities from skin. Vitamin E helps in acne breakouts and lightening of scars. Zinc and omega 3 fatty acids are also good for skin. Do not take more than the recommended daily amount of any vitamin, unless under supervision from your doctor. For more queries and assistance visit a dermatologist. Hope it helps.
Best luck and regards!