Intralesional injection of a steroid is done as an out-patient procedure, with no special preparation involved. You should tell the doctor if you have any allergies or problems with your general health. Although the area to be treated can be numbed with a local anaesthetic, this is not normally necessary; the discomfort associated with the steroid injection is very similar to that caused by an injection of local anaesthetic. Depending on the size of the area to be treated, a number of injections may be required. Your doctor will probably place a small dressing over the injected site, and this can be removed after a few hours. Depending on the condition being treated, you may be offered further treatment sessions, at least several weeks apart.