Everyone gets the odd spot. Spots occur when there's a build-up of oil called sebum under the skin. Sebum is essential to keep your skin and hair lubricated. It travels up the hair shaft and out through your pores. When these pores become blocked, a whitehead or blackhead may develop. But if these blocked pores become infected, you may get a red pus-filled spot. A number of factors - including hormones, bacteria, some medications and genetics - play a role. Contrary to popular belief, chocolate and greasy food don't give you spots.

*Watch what touches your face: anything that increases the oil production increases your chances of getting spots. Keep your hair clean. Try not to rest your hands or telephone receiver on your face and avoid tight clothes or bag straps that rub your skin. Pollution and high humidity can also cause spots.
*Wash spotty areas with a gentle cleanser: facial scrubs, astringents and masks generally aren't recommended as they can irritate skin. Excessive washing and scrubbing can make acne worse.
*Don't pick or squeeze your spots: it may be tempting, but it can cause infection and scarring.
*Avoid irritants: using oily or greasy makeup, sunscreens and hair products can make spots worse. For some people, the sun worsens acne and some acne medications can make you more susceptible to the sun's rays. Use a sunscreen that doesn't clog your pores.
*Use a cream containing benzoyl peroxide: research shows that these products help to unblock pores, kill bacteria, and reduce oiliness. For persistent acne, consult a doctor
The Guardian