RESUMO
BACKGROUND: Thyroid storm (TS) is a rare life-threatening condition that is characterized by fever and altered mental status precipitated by endogenous or exogenous critical events, illness/injury, acute iodine load, and thyroid or non thyroid surgery. A large number of thyroid extracts are available and extensively used, even though they are not recommended clinically in hypothyroid or euthyroid patients. Consumption of such products can be dangerous and result in life-threatening TS. Here, we report a case of TS caused by inadvertent intake of very high dosages of triiodothyronine (T3) and thyroxine (T4) in compounded thyroid extracts. Plasmapheresis may be considered an option for the management of exogenous TS. PATIENT FINDINGS: A 62-year-old woman with no significant past medical history presented with severe myalgia, fever, tachycardia, and blood pressure of 170/80 mmHg, which precipitated to an altered mental state within 24 hours. Neurological examination did not reveal any focal deficit or any signs of meningeal irritation. Further investigation revealed that she had been taking thyroid supplements. The patient had accidentally been supplied with a batch of thyroid extract pills that had an inadvertently high content of T4. Her free T3 (FT3) and free T4 (FT4) levels were found to be very high beyond the laboratory readable range (FT3>30 pg/mL; FT4>6.06 ng/dL; thyrotropin [TSH]=0.07 IU/mL). SUMMARY: Three days post commencement of standard conservative management of TS, the patient developed posterior reversible encephalopathy syndrome, resulting in a seizure. She remained unresponsive and in a poor mental state. The confirmed exogenous etiology for TS led to a decision to conduct plasmapheresis. Plasmapheresis conducted for two consecutive days proved successful as a therapeutic measure for TS and improved her thyroid profile as well as her mental state. CONCLUSIONS: The inappropriate use of thyroid extracts in euthyroid and hypothyroid patients can result in life-threatening TS. Plasmapheresis is probably a life-saving treatment in patients who are exposed to amounts of thyroid hormone far in excess of that usually produced by the thyroid gland.