This primarily happens in the liver, the main site at which cortisone becomes cortisol after oral or systemic injection, and can thus have a pharmacological effect. After application to the skin or injection into a joint, local cells that express 11β-hydroxysteroid dehydrogenase type 1 instead convert it to active cortisol. A cortisone injection may provide short-term pain relief and may reduce the swelling from inflammation of a joint, tendon, or bursa in, for example, the joints of the knee, elbow and shoulder and into a broken coccyx.Cortisone is also used by dermatologists to treat keloids, relieve the symptoms of eczema and atopic dermatitis, and stop the development of sarcoidosis. Side effects
Oral use of cortisone has a number of potential systemic adverse effects, including asthma, hyperglycemia, insulin resistance, diabetes mellitus, osteoporosis, anxiety, depression, amenorrhoea, cataracts, glaucoma, Cushings syndrome, increased risk of infections and impaired growth. With topical application, it can lead to thinning of the skin, impaired wound healing, increased skin pigmentation, tendon rupture and skin infections (including abscesses). History
Cortisone was first identified by the American chemists Edward Calvin Kendall and Harold L. Mason while researching at the Mayo Clinic. During the discovery process, cortisone was known as compound E (while cortisol was known as compound F). In 1949, Philip S. Hench and colleagues discovered that large doses of injected cortisone were effective in the treatment of patients with severe rheumatoid arthritis.
Here, the zona fasciculata and zona reticularis, in response to ACTH, secrete glucocorticoids, in particular cortisol. In various peripheral tissues, notably the kidneys, cortisol is inactivated to cortisone by the enzyme corticosteroid 11-beta-dehydrogenase isozyme 2. This is crucial because cortisol is a potent mineralocorticoid and would cause havoc with electrolyte levels (raising blood sodium and lowering blood potassium levels) and raise blood pressure if it were not inactivated in the kidneys.Because cortisone must be converted to cortisol before being active as a glucocorticoid, its activity is less than simply administering cortisol directly (80–90%). Popular culture
Addiction to cortisone was the subject of the 1956 motion picture Bigger Than Life, produced by and starring James Mason. Though it was a box-office flop upon its initial release, many modern critics hail the film as a masterpiece and brilliant indictment of contemporary attitudes toward mental illness and addiction. In 1963, Jean-Luc Godard named it one of the ten greatest American sound films ever made.John F. Kennedy was regularly administered corticosteroids such as cortisone as a treatment for Addisons disease. See also
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Central serous retinopathy
Corticosterol

Notes
Bibliography
Bonagura J., DVM;  et al. (2000). Current Veterinary Therapy. Vol. 13. pp. 321–381. Ingle DJ (October 1950). "The biologic properties of cortisone: a review". J. Clin. Endocrinol. Metab. 10 (10): 1312–54. doi:10.1210/jcem-10-10-1312. PMID 14794756. Woodward R. B.; Sondheimer F.; Taub D. (1951). "The Total Synthesis of Cortisone". Journal of the American Chemical Society. 73 (8): 4057. doi:10.1021/ja01152a551.