Corticosteroids are powerful anti-inflammatory drugs that relieve severe pain and swelling. You take them by mouth or inject them directly into a joint or muscle. They're not the same as the muscle-building type of anabolic steroids. Prednisone is a common steroid. It can help for a short time, but it might make the skin rash worse. Doctors prescribe steroids only when you really need them. If you use them for a long time, you could have serious side effects such as brittle bones, weight gain, hypertension and diabetes