Acne

At the heart of acne lies the pimple -- a plug of fat, skin, and keratin. When open, the plug is called a blackhead, closed, a whitehead. Often seen on the face, chest, and back, acne is caused by many things, including hormones. To help control it, keep oily areas clean and don't squeeze pimples (it may cause infection and scars). Only three medications are proven effective for acne treatment: benzoyl peroxide, retinoids, and antibiotics.