ESPE Abstracts

Aim: To highlight the diagnosis of Hashitoxicosis and its distinction from Graves’s disease. Subjects with Hashimoto’s thyroiditis are often euthyroid or may experience subclinical or true hypothyroidism. However, in 5 to 10% of children, a transient phase of hyperthyroidism, called Hashitoxicosis, may occur.

Patients-Methods: Three female patients, were referred at the ages of 6¹/₁₂, 9⁶/₁₂ and 12⁴/₁₂ years respectively. The first patient suffered from Type I diabetes mellitus and during a routine evaluation, severe hypothyroidism was detected due to Hashimoto’s thyroiditis. Substitution therapy with L-Thyroxine was initiated. Subsequently she developed subclinical hyperthyroidism and then returned to a hypothyroid status. The second patient passed from a phase of hyperthyroidism to euthyroidism, while the third patient first experienced hypothyroidism, then subclinical hyperthyroidism and later became euthyroid. Thyroid hormone course is presented with the table.

Results: In all cases, the diagnosis of thyrotoxicosi was established by careful history and clinical examination and a series of diagnostic tools. Thyroid ultrasound showed mainly structural gland heterogeneity. The presence of positive TSIs (Thyroid-stimulating immunoglobulins) in the first case, made it even more difficult to diagnose. For this reason, a Tc 99m scintigraphy was requested, showing a diffuse and slightly increased intake in both lobes, compatible with Hashitoxicosis. All three patients showed no evidence of clinical hyperthyroidism and were clinically evaluated every 2 weeks. Subclinical hyperthyroidism lasted from about 30 to 90 days. If however patients demonstrate clinical hyperthyroidism, especially cardiovascular signs, propranolol is recommended.

Conclusions: Hashitoxicosis is a rare event that needs to be recognized and managed appropriately. Treatment with antithyroid medications is not required in most cases. Scintigraphy is not always necessary while prospective careful monitoring of patients is essential.