The steroid medications are related to cortisone, which is produced by the body itself. The purpose of the injection is to calm down the excessive inflammatory process that may be going on because of injury, excess use, or similar problems. Cortisone injections can also be used for diagnosing some conditions, such as carpal tunnel syndrome, wrist ligament tears, etc. The form of cortisone that I use is called triamcinolone acetonide. It has the longest duration of action and the greatest potency of the cortisone. The most likely side effect is decrease of skin pigmentation in a region about the size of a dime or a quarter. This is not permanent, but may last up to a year.