Refractory thyrotoxicosis induced by iodinated contrast agents treated with therapeutic plasma exchange. A case report.

Excess free iodide in the blood (ingested or injected) may cause thyrotoxicosis in patients at risk. Iodinated contrast solutions contain small amounts of free iodide and may be of significance for patients affected by Graves' disease, multinodular goiter or living in areas of iodine deficiency. Herein, we report a 57 elderly woman with a clinical history of multinodular goiter presented with a thyrotoxicosis induced by an iodinate contrast agent used during computed tomography scan. Because of the patient's resistance to conventional antithyroid drugs, she was treated with therapeutic plasma exchange (TPE). TPE is used in the treatment of several immunologic and nonimmunologic disorders. Temporary improvement after TPE in cases with thyrotoxicosis has been reported. In our patient's case, we observed an improvement in the thyroid hormone laboratory values as well as clinical findings. TPE can be an addition treatment when standard therapies for thyrotoxicosis fail providing the clinician with an adjuvant tool for rapid preparation of such a patient for thyroidectomy surgery. (c) 2008 Wiley-Liss, Inc.