Steroids are a large group of chemical substances classified by chemical structure. Steroids include drugs used to relieve swelling and inflammation.
Dexamethasone is a steroid used to achieve prompt suppression of inflammation in many conditions. Some examples include rheumatoid arthritis, systemic lupus, acute gouty arthritis, psoriatic arthritis, ulcerative colitis, and Crohn's disease. Severe allergic conditions that fail conventional treatment may also respond to dexamethasone. Examples include bronchial asthma, allergic rhinitis, drug-induced dermatitis, and contact and atopic dermatitis. Chronic skin conditions treated with dexamethasone include dermatitis herpetiformis, pemphigus, severe psoriasis and severe seborrheic dermatitis. Chronic allergic and inflammatory conditions of the uvea, iris, conjunctiva and optic nerves of the eyes are also treated with dexamethasone. Dexamethasone is also used in the treatment of blood cell cancers (leukemias), and lymph gland cancers (lymphomas). Blood diseases involving the destruction of platelets by the body's own immune cells (idiopathic thrombocytopenia purpura), and destruction of red blood cells by immune cells (autoimmune hemolytic anemia) can also be treated with dexamethasone. Other miscellaneous conditions treated with this medication include thyroiditis and sarcoidosis. Finally, dexamethasone is used as a hormone replacement in patients whose adrenal glands are unable to produce sufficient amounts of corticosteroids.
Information is taken from www.medicinenet.com