Benzoyl peroxide is the single most effective anti-acne topical ingredient. The American Academy of Dermatology acne treatment guidelines place benzoyl peroxide on the top of the list of suggested anti-acne medications. Other ingredients, such as retinoids (Differin, adapalene) and azelaic acid, are significantly less effective for treating active acne. To your question: The skin around the mouth and neck is very sensitive. Do NOT apply benzoyl peroxide (or adapalene) creams to these areas. Wash your hands after you use these creams. This will avoid touching and spreading the creams to the neck by mistake.
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