Subacute Hyperthyroidism Induced by Treatment with Lithium Salts

Abstract

Lithium treatment is usually indicated in bipolar disorder. It is associated with hypothyroidism and very rarely with hyperthyroidism. We report here the results of the exploration of a case of thyrotoxicosis occurring during treatment with lithium salts. This was a 16-year-old patient with ongoing lithium treatment for two and a half years who presented with a thyrotoxicosis syndrome without a context of iodine overload or an episode of anterior cervical pain that could suggest subacute thyroiditis or orthopathic sign. The assessment of the exploration of this patient reveals biological hyperthyroidism without anti-TSH receptor antibodies, a normal ultrasound, and white scintigraphy which makes it possible to evoke the diagnosis of subacute thyroiditis (absence of the context of iodine overload). Note the interest in a thyroid assessment before and during treatment with lithium salts. Moreover, scintigraphy occupies a place of choice in the exploration of hyperthyroidism, particularly in the context of normal thyroid ultrasound imaging.