Prednisone is a medication designed to prevent the release of substances in the body that can cause inflammation, thereby lowering redness and swelling. It can treat low corticosteroid levels, or other conditions in patients with normal corticosteroid levels, such as allergic disorders, skin conditions, ulcerative colitis, arthritis, lupus, psoriasis, and breathing disorders.Prednisone can also be used to treat the symptoms of certain types of cancer. It is sometimes used with antibiotics to treat a certain type of pneumonia in patients with HIV/AIDS.