If you have only a few plaques, your doctor will probably try a prescription cream first. You put these directly on your skin. They either help with inflammation or slow the growth of skin cells. Examples include corticosteroids, vitamin D, vitamin A, and anthralin. You can also try over-the-counter topical medicines. Both salicylic acid and coal tar are approved to treat psoriasis. Other ingredients may soothe itch and remove scale, including aloe vera, jojoba, zinc pyrithione, and capsaicin.