Factitious endocrinopathies: Thyrotoxicosis

Factitious thyrotoxicosis is the presence of excess circulating thyroid hormone from an exogenous source. It can be iatrogenic or it can occur due to intentional thyroid hormone misuse or abuse. It can also occur due to accidental ingestion, pharmacy error, or inadvertent exposure to unlabeled thyroid hormone in supplements or contaminated hamburger meat. Consequences range from mild thyrotoxic symptoms to more serious or life-threatening sequelae including thyrotoxic periodic paralysis, seizure, coma, arrhythmias, myocardial infarction, and thyroid storm. If unclear from the history, differentiating factitious thyrotoxicosis from other etiologies of thyroid hormone excess is challenging, and may require radioactive iodine uptake and serum thyroglobulin testing. In most cases, treatment simply consists of stopping the exogenous thyroid hormone exposure with subsequent monitoring. However, in cases of massive acute poisoning with thyroid hormone, gastric decontamination strategies and inpatient care in a monitored setting with measures to reduce circulating T3 levels may be needed.