De Quervain’s tenosynovitis is a common cause of radial-sided wrist pain. Corticosteroid injections are widely used as first-line treatment, but the optimal corticosteroid and dosage remain unclear. This study compared the efficacy and safety of betamethasone and dexamethasone in the treatment of De Quervain’s tenosynovitis.

This single-center retrospective cohort study included adults that were diagnosed with De Quervain’s tenosynovitis and treated with a corticosteroid injection using either betamethasone or dexamethasone between October 1, 2021, and October 30, 2025. Patients were identified using diagnostic and procedural codes and grouped by medication type and dosage. The primary outcome was treatment success at 3, 12, and 24 months, defined as continued symptomatic relief without additional intervention or documented loss of relief. Secondary outcomes included treatment success by dosage, treatment durability, conversion to surgery, and adverse events.

A total of 514 patients met inclusion criteria. Betamethasone had a higher treatment success rate at 3 months than dexamethasone (82.7% vs 64.9%, p   <  0.001), longer median treatment durability (109.7 vs 72.1 days, p   <  0.001), and a lower rate of conversion to surgery (18.0% vs 30.4%, p  = 0.001). Among dose subgroups, betamethasone 3 mg had the highest treatment success at 12 months. Treatment success rates were similar between groups at 12 and 24 months. Adverse events were infrequent and mild in both groups.

Betamethasone was associated with greater short-term symptomatic relief, longer treatment durability, and lower conversion to surgery than dexamethasone. Long-term treatment success and adverse-event rates were similar between groups.

Level III, retrospective cohort study, therapeutic.