When possible, local steroid treatments are prescribed instead of systemic steroids. Steroids work by decreasing inflammation and reducing the activity of the immune system. Inflammation is a process by which the body's white blood cells and chemicals protect the body against infection and foreign substances such as bacteria and viruses. This may cause inflammation to work against the body's own tissues and cause damage. Inflammation is characterized by redness, warmth, swelling and pain.
Steroids reduce the production of inflammatory chemicals in order to minimize tissue damage.
Steroids also reduce the activity of the immune system by affecting the function of white blood cells. Steroids are used to treat a variety of conditions in which the body's defense system malfunctions and causes tissue damage. Steroids are the main therapy for certain diseases. For other conditions, steroids may be used only sparingly, or when other treatments have not been successful. For example, steroids may help prevent the progression of kidney inflammation, which can lead to kidney failure in people who have lupus or vasculitis.