Cortisone Injection

How Cortisone Injection Works

Cortisone is a naturally occurring corticosteroid hormone produced by the body’s adrenal glands. Corticosteroids are a class of medications that are related to natural cortisone that are designed to work in a similar way inside the body.

Cortisone affects many parts of the body including the immune system. It helps lower levels of prostaglandins, hormone-like lipids that play a role in causing inflammation (heat, redness, swelling, and pain), and it can soften the response of the immune system’s T-cells and B-cells, which are types of white blood cells.

When delivered directly into a joint or tendon impacted by arthritis, corticosteroids mimic the effect of natural cortisone and reduce inflammation. Its relatively fast action compared to many other treatments helps make cortisone injections a useful tool in treating arthritis.

Side Effects of Cortisone Injection

Cortisone injections are usually fairly well tolerated by patients. The biggest concern is often the very rare possibility (1 in 15,000 to 1 in 20,000) of infection. Patients should see a doctor immediately if they get a fever after an injection, or if an injected area becomes very painful, red, or swollen.

Possible side-effects include:

  • Infection – rarely a joint can become infected after injection. Steroids in general can also make it harder the body to fight infections. Patients should call their doctor if they have a fever or think they have an infection.
  • Injury to the joint or tendon – A steroid injection can rarely cause injury to a joint or a tendon. Patients are encouraged to discuss this risk with their doctor.
    • Tendon rupture – If a steroid injection is performed around a tendon, a rare risk is rupture of the tendon. This is more common around tendons that are already weak or partially ruptured, and more common in those in the legs. If a steroid injection is given around a tendon it is best to rest and immobilize the area for 24-48 hours.
  • Post injection pain – Some patients may experience increased pain and discomfort in the injected joint. It is thought to be caused by a reaction to the steroid or perhaps bleeding into the joint. Post-injection pain can be treated with ice packs or with pain medications including NSAIDs.
  • Flushing – After an injection some patients feel “flushed”. This usually isn’t serious but patients should tell their doctor if this happens.
  • Rise in blood sugars – A steroid injection can sometimes cause a rise in blood sugars in patients who have diabetes. These patients should make sure to test your blood sugars for a few days after the injection.
  • Skin changes – A steroid injection can rarely cause changes to the skin:
    • Loss of pigment – Steroid injections can cause an area of the skin to lose pigment (turn white; called vitiligo). This is more common in darker skinned people.
    • Loss of fat layer – Steroids can also cause loss of the fat layer just below the skin (called fat necrosis) that may cause a depression or unusual appearance, and may cause the skin to turn a purple color. It is not serious but it can look funny. Over time the fat usually returns. When this happens, usually the steroid injection worked really well.
  • Sleep trouble & increased energy – A steroid injection can sometimes make patients feel full of energy. This can sometimes make it difficult to sleep.

Patients should talk to their doctor if they are concerned about any side effects.

Who Should NOT Take Cortisone Injection

Patients who should NOT be taking Cortisone include:

  • Patients who have had a previous allergic reaction to corticosteroids or an ingredient in the shot
  • Patients who have not responded well to Cortisone treatment
  • Possibly patients with an active infection or a systemic fungal infection
  • Possible patients with a blood clotting disorder (such as haemophilia).

Patients who become pregnant while receiving Cortisone therapy should tell their doctor. It is generally advisable to avoid all medications during pregnancy and while trying to become pregnant. However, local steroid injections are believed to be one of the safer treatments for arthritis during pregnancy.

When to Call a Doctor

Patients taking Coritisone should call their doctor if they feel unwell after receiving an injection, or if they are concerned about any side effects.

Other reasons to call a doctor after receiving a corticosteroid injection include:

  • Severe pain in the area injected
  • Fever or possible infection
  • Skin changes or loss of pigment

Cortisone Injection Video

Watch Dr. Andy Thompson, a Canadian rheumatologist, introduce Cortisone Injection.