Topical salicylic acid treats acne by reducing swelling and redness and unplugging blocked skin pores to allow pimples to shrink. It treats other skin conditions by softening and loosening dry, scaly, or thickened skin so that it falls off or can be removed easily.
BHA is an abbreviation for beta hydroxy acid, also known as salicylic acid. Don't let the word 'acid' put you off. BHA is not corrosive or abrasive and actually has soothing properties. Its naturally anti-inflammatory nature makes it much kinder on your skin than gritty scrubs and most types of cleansing brushes.
BHA / Salicylic Acid - Differences & Effects Quite simply put: there is no difference between the two. Salicylic acid is a type of BHA, long referred to as beta-hydroxy acid. The active ingredient is a chemical peel that is obtained from white willow (Salix alba).