Side-effects of steroid injections are very unlikely but occasionally people notice a flare-up of pain in the injected area within the first 24 hours after the injection. This usually settles on its own within a couple of days but taking simple painkillers like paracetamol will help. Evidence-based professional reference pages https://www.ird.gov.lk/en/Lists/QuickFeedback/DispForm.aspx?ID=262372