Endocrine Abstracts

Background: Clinically severe or recurrent subacute thyroiditis (SAT) frequently requires treatment with high cumulative doses of systemic steroids. Such therapy is associated with high risk of steroid-related complications. The DLISAT study aims to evaluate the efficacy and safety of intrathyroidal dexamethasone and lidocaine injections (DLI) in specific patient cohorts compared to standard oral steroid therapy. This report presents preliminary results after the initial six months of the study.

Methods: The study group (SG) comprised five patients, including two patients with treatment-naive SAT and contraindications or lack of consent for systemic therapy, two patients experiencing SAT recurrence soon after completion of oral therapy and one patient with steroid-dependent SAT. The control group (CG) consisted of five consecutive patients treated with oral prednisone. In SG patients, 4 mg of dexamethasone (1 ml of solution), with or without 1 ml of 2% lidocaine, was injected into each thyroid lobe. The injections were ultrasound (US)-guided. On the basis of the obtained results doses were repeated every 2-5 days, as required. Parameters measured before and after injections included pain severity, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), thyroid-stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), and thyroglobulin (Tg). Ultrasound and shear wave elastography (SWE) results were analyzed before and after each injection.

Results: All SG patients exhibited an excellent rapid and long-term response with no side effects, except for injection-related discomfort. The first injection in SG patients led to significant pain reduction, improved ESR, CRP, thyroid parameters, US and SWE findings. The number of doses required for total recovery were 2-6 and a mean dexamethasone dose for the entire therapy was 32 mg. The longest therapy period was 20 days and no recurrence was observed. Persistent hypothyroidism occurred in one CG patient. In comparison, the mean therapy period in CG was 93 days and a mean dose of oral prednisone was 1580 mg.

Conclusion: The efficacy and safety of DLI in SAT were excellent and the method seemed more beneficial than standard oral steroid therapy, especially in patients with high risk of steroid-related complications.