Salicylic acid is a beta hydroxyl acid extracted from the bark of the willow tree, and has a broad variety of skin-related applications

Beta hydroxyl acids are more suited to the treatment of surface skin conditions than their alpha hydroxyl acid association, because they have bigger molecules and do not reach the layers of the skin so readily.

Since alpha hydroxyl acids travel deep through the skin, they can cause more inflammation and make the skin worse. So did the salicylic acid make acne worse?

The main application of salicylic acid is to reduce the effects of mild acne. Acne is caused by excess oil production and the loss of skin cells in hair follicles.

This blocks the follicle and provides a place for bacteria to develop, resulting in inflammation and a pinch. Salicylic acid acts by slowing down the shedding of skin cells and by breaking down the substance that produces the spot.

You should mix salicylic acid with a number of other compounds to improve its acne-fighting properties; retinol is a perfect example of this.

However, you cannot mix salicylic acid with ammonia, benzoyl peroxide or resorcinol because it would be too harmful to the skin and increase oil production, rendering the condition worse.

You will also see salicylic acid used in chemical peels to reduce the presence of mild acne scarring and to purify the skin in spite of disadvantages of salicylic acid for acne.

The concentration of salicylic acid used would have an effect on the quality of the peel. Up to 20% salicylic acid may be used, but this can induce severe skin peeling for around three days and may be too intense to be used in weekly peels.

Salicylic acid should be used as a treatment for many other skin disorders. It is also an important ingredient in anti-dandruff shampoos and is used to treat skin conditions such as psoriasis.

It also has collagen strengthening properties that make it suitable for slowing down the production of wrinkles.