Salicylic acid, an over-the-counter medication that can be obtained without a doctor's prescription, is a Federal Drug Administration approved treatment for cases of mild psoriasis.
Salicylic acid is a keratoolytic, a substance that causes the outer layer of skin to peel away. It works to treat a variety of skin conditions; in the case of psoriasis, salicylic acid causes scales to soften and fall away more easily.
When using salicylic acid to treat mild psoriasis, be sure not to overdo it. Strong salicylic acids can lead to skin irritation or hair loss if applied too frequently. But when used in moderation, salicylic acid can provide a certain measure of relief for sufferers of mild psoriasis.