Chapter 81 - Treatment Regimens in Toxic and Diffuse Goiters in Iodine Deficiency: Goiter and Hyperthyroidism in Iodine Deficiency

Abstract

Diffuse goiter and nodular thyroid disease arise as a sequel to environmental conditions of long-lasting alimentary iodine deficiency. Hyperthyroid toxic and euthyroid nontoxic variants of the diseases may be discerned according to the extent of functional abnormalities of the thyroid or morphological changes of the gland. Correct diagnosis requires prior exclusion of other types of hyperthyroidism, such as Graves' disease and thyroid malignancies. From a functional point of view, euthyroid diffuse goiter and hypofunctional thyroid nodules have to be discerned from hyperthyroid conditions, mainly toxic adenoma and toxic multinodular goiter. Therapeutic options include drugs, radioiodine treatment and surgery. Radioiodine treatment is particularly well-suited for toxic adenoma and multinodular toxic goiter. Surgery is required in cases of suspected malignancy and large goiters or nodules causing symptoms of obstruction. While the efficacy of both levothyroxine and iodine in existing disease is limited, prevention of the occurrence or recurrence of diffuse or nodular goiter is readily achieved by small amounts of iodine correcting iodine deficiency. Apart from correcting the existing disease, which frequently requires a more radical and destructive approach, prevention of the deterioration of the present condition and the formation of new thyroid nodules may be readily achieved through long-term prophylaxis with iodine; this should not be neglected. The same is true for prevention of recurrent diseases after successful employment of radioiodine or surgical treatment.