Disadvantages of cortisone injections are the necessity of piercing the skin with a needle as well as potential short and long term side effects. It should be emphasized that while each of these side effects is possible, they usually do not occur.
Short term side effects are uncommon, but include shrinkage (atrophy) and lightening of the color (depigmentation) of the skin at the injection site, introduction of bacterial infection into the body, local bleeding from broken blood vessels in the skin or muscle, soreness at the injection site, and aggravation of inflammation in the area injected because of reactions to the corticosteroid medication (postinjection flare). Tendons can be weakened by corticosteroid injections in or near tendons. Tendon ruptures as a result have been reported.
In persons who have diabetes, cortisone injections can elevate blood sugar. In patients with underlying infections, cortisone injections can suppress somewhat the body's ability to fight the infection and possibly worsen the infection or mask the infection by suppressing the symptoms and signs of inflammation. Generally, cortisone injections are used with caution in persons with diabetes and avoided in persons with active infections. Cortisone injections are used cautiously in persons with blood clotting disorders.
Long-term side effects of corticosteroid injections depend on the dose and frequency of the injections. With higher doses and frequent administration, potential side effects include thinning of the skin, easy bruising, weight gain, puffiness of the face, elevation of blood pressure, cataract formation, thinning of the bones (osteoporosis), and a rare but serious damage to the bones of the large joints (avascular necrosis).