<p>Salicylic Acid has a potent keratolytic &amp; a slight antiseptic action when applied topically to the skin. In low concentrations, the drug has keratoplastic activity (correction of abnormal keratinization) &amp; in higher concentrations, the drug has keratolytic activity (causes peeling of skin). Salicylic Acid softens &amp; destroys the stratum corneum by increasing endogenous hydration (water concentration), probably because of decreased pH, which causes the cornified epithelium (horny layer of the skin) to swell, soften, &amp; then desquamate. Necrosis of normal skin has been associated with overuse of the drug. At high concentrations, Salicylic Acid has a caustic effect. Moisture is essential for Salicylic Acid to exert its action on the skin and for maceration and desquamation of epidermal tissue to occur. The drug has weak antifungal &amp; antibacterial activity.</p>