Hipertiroidismo y captaciones de yodo bajas en una paciente con enfermedad de Graves

Thyrotoxicosis factitia is defined as thyrotoxicosis resulting from exogenous ingestion of thyroid hormone, usually in patients with a psychiatric disorder. Diagnosis can be difficult and this entity should be suspected in patients with high free tiroxine (T4) concentrations, low or suppressed thyroglobulin concentrations, normal urinary iodide excretion and low or suppressed ¹³¹I uptake. To establish the differential diagnosis, thyrotoxicosis factitia must be distinguished from several diseases with low ¹³¹I uptake, such as Graves’ disease, subacute thyroiditis, hyperthyroidism due to excessive iodine intake, struma ovarii and metastasis from thyroid cancer. Treatment is based on b-blockers to reduce symptoms and avoid iatrogeny. We present a case of thyrotoxicosis factitia treated in our outpatient clinic.