There are many reasons a break-out could be happening, but the best way to stop acne in its tracks is, first and foremost, AVOID picking it at all costs. Picking acne leads to irritation and can lead to scarring or worse infection. We've all been there, and it sucks.
Immediately apply ice to the area for at least 60 seconds. A cool trick is to freeze green tea in an ice tray and use the green tea ice cubes.
Green Tea contains an antioxidant called EGCG that acts as an anti-inflammatory and prevents the abnormal colonization of P. Acnes bacteria, the cause of acne.
Stick with ONE acne zapping ingredient such as retinoids, benzoyl peroxide, salicylic acid, or sulfur. Using several different ingredients increases the risk of allergic reactions, redness, and dry skin.
Avoid wearing acne-causing makeup. You'd be surprised how many foundations have pore-clogging ingredients. It's essential when breaking out that you use a moisturizing acne foundation.
Finally, DO NOT EXFOLIATE. Exfoliating will only make the pimple irrupted or instigate a breakout.