Endocrine Abstracts

We present a challenging case of Graves’ disease complicated by Propylthiouracil (PTU)-induced ANCA-positive vasculitis and recent iodine contrast exposure, creating a therapeutic dilemma where standard treatment options were severely limited. A 60-year-old man was diagnosed with graves’ disease in december 2020 and treated with carbimazole for one year. On stopping carbimazole, he went into relapse and was switched to PTU in 2022 as he reported side effects on re-starting carbimazole. Although radioactive iodine (RAI) therapy was offered, he initially declined. Nearly two years into PTU therapy, he developed worsening breathlessness, and CT chest revealed a new pericardial effusion. He was treated presumptively for pericarditis, but follow-up imaging showed minimal improvement. By early 2025, he experienced migratory joint pain, swelling, and persistently raised inflammatory markers. During his work-up, he received a significant iodine load from contrast-enhanced imaging. Autoimmune screening confirmed vasculitis (positive p-ANCA and anti-MPO). PTU was discontinued and corticosteroids initiated, leading to clinical improvement. Given florid hyperthyroidism and recent iodine exposure, his case was reviewed at the endocrine multidisciplinary meeting. Carbimazole was restarted as a bridging therapy; despite its vasculitis risk, it remains the best option until RAI, which is currently ineffective due to iodine saturation, can be given. Surgical thyroidectomy was unsafe due to severe thyrotoxicosis. These limitations created a narrow therapeutic window requiring careful multidisciplinary planning. This case highlights the rare but serious complication of PTU-induced vasculitis and the complexities of managing florid hyperthyroidism when drug intolerance, iodine exposure, and surgical risk converge — truly an endocrinologist’s worst nightmare.