I looked up treatments for Trigger finger in Official Disability Guidelines (Dec 2025), a subscription evidence-based database used by the Department of Insurance in the State of Texas, and this is what it has documented for using corticosteroid injections for Trigger finger:
Trigger finger: Recommended. There is good evidence supporting local corticosteroid injections (CSI) for trigger finger conditions. One or two injections of lidocaine/corticosteroid into or near the thickened area of the flexor tendon sheath of the affected finger are usually sufficient to cure the symptoms and restore function. Treatment of trigger finger with local CSI is simple and safe, but the risk of recurrence over the first year is significant. CSI should be the first-line treatment for trigger fingers in nondiabetic patients, whose success rate is significantly lower, proving to be relatively ineffective for type 1 diabetics. Surgical release of the first annular (A1) pulley has the highest cure rate overall for diabetics and nondiabetics alike, without higher surgical complications in diabetics. CSI into the flexor sheath is a generally effective method of treating triggering fingers/thumb and should be considered as the preferred initial treatment. An randomized control trial concluded that local injection with triamcinolonacetonide is effective and safe compared to placebo injection, with effectiveness up to 12 months. A systematic review of various treatments for trigger finger found moderate-level evidence to support CSI over the short-term.