How often cortisone injections are given varies based on the reason for the injection. This is determined on a case-by-case basis by the health care practitioner. If a single cortisone injection is curative, then further injections are unnecessary. Sometimes, a series of injections might be necessary; for example, cortisone injections for a trigger finger may be given every three weeks, to a maximum of three times in one affected finger. In other instances, such as knee osteoarthritis, a second cortisone injection may be given approximately three months after the first injection, but the injections are not generally continued on a regular basis.
Of the two trials that enrolled only children, one reported a positive effect with corticosteroid use, and the other found no difference between the treatment groups. The studies that enrolled children, adolescents, and adults did not report outcomes by age, so reviewers were unable to stratify effectiveness by age group. No significant differences were noted in adverse event rates, complications of streptococcal disease, or recurrence or relapse rates between the corticosteroid and placebo groups, although conclusions regarding safety were limited because of the small number of trials.