A GP, rheumatologist, orthopaedic surgeon, rheumatology nurse or physiotherapist will choose the most appropriate steroid mixture and dose for your condition and symptoms. They may want to check your blood pressure and blood sugar before your first injection as steroid injections can cause these to rise.
They might delay the injection if either is raised. Depending on where the pain and inflammation is, steroids can be injected:
- directly into an inflamed joint (intra-articular injection)
- into the soft tissues close to the joint (peri-articular injection)
- into a muscle (intra-muscular injection).
Most injections are quick and easy to perform. An ultrasound scan, however, may be used to find exactly where the inflammation is so the steroid can be injected into a precise spot. However, many injections can be given without the need for ultrasound.
Sometimes you'll be given a local anaesthetic with the steroid to reduce the discomfort of the injection. If you do have a local anaesthetic, your pain should be relieved within minutes but it'll usually wear off within half an hour unless the anaesthetic selected is long acting. You may have some numbness from the anaesthetic which may last up to 24 hours.
You may want to arrange transport home after the injection, especially if you've had a local anaesthetic, because numbness from the anaesthetic can make it difficult to drive.
If you have an injection into a joint, you should rest it, or at least avoid strenuous exercise, for the first 1–2 days. It's also important, however, not to rest for too long. If you're having a course of physiotherapy, the physiotherapist may be keen to give more intensive mobilisation treatment after the injection, while your joint is less painful.
If the injection is very helpful, and other treatments are either unsuitable or less effective for you, it may be repeated if necessary. However, injections are often most useful in buying time while you and your doctor are finding the right medications to control your arthritis in the long term. Once your arthritis is well controlled the need for injections should be reduced.
How long do local steroid injections take to work?
A number of different steroids are available for injection. Short-acting soluble steroids can give relief within hours and should last for at least a week. The longer-acting, less soluble steroids may take around a week to become effective but can ease your symptoms for two months or longer.