Triamcinolone acetonide injection is a medication that is used to treat a variety of inflammatory and autoimmune conditions. It belongs to a class of drugs called corticosteroids, which work by reducing inflammation and suppressing the immune system.Triamcinolone acetonide injection is given directly into a muscle, joint, or other tissues in the body. It is used to treat conditions such as arthritis, bursitis, tendonitis, gout, lupus, and other autoimmune disorders. It is also used to treat allergic reactions, skin conditions such as eczema and psoriasis, and certain types of cancer.