Triamcinolone is a topical steroid. It reduces the actions of chemicals in the body that cause inflammation, redness, and swelling. Triamcinolone topical is used to treat the inflammation caused by a number of conditions such as allergic reactions, eczema, and psoriasis. The dental paste form of triamcinolone is used to treat mouth ulcers. Triamcinolone topical may also be used for purposes not listed in this medication guide.