OTC topicals are available in pharmacies, drugstores, supermarkets or directly from the manufacturer without a doctor’s prescription. They come in many different forms. Two active ingredients, salicylic acid and tar, are approved by the FDA as treatments for psoriasis.
Salicylic acid is classified as a keratolytic, or peeling agent, and works by causing the outer layer of skin to shed. It is a common and effective treatment for a wide variety of skin problems. As a psoriasis treatment, it acts as a scale lifter, helping to soften and remove psoriasis scales.
Strong salicylic acid preparations can cause irritation if left in contact with the skin too long. The body may absorb too much salicylic acid if used over large areas of the skin. Salicylic acid may also weaken hair shafts and make them more likely to break, leading to temporary hair loss.