To the Editor.
—Hyperthyroidism with poor or no radioactive iodine 123 uptake on thyroid scanning may be found with subacute thyroiditis, silent thyroiditis, or factitious thyrotoxicosis.1-5 Factitious thyrotoxicosis can usually be confirmed by the administration of thyrotrophin (thyroid-stimulating hormone) showing thyroid gland incorporation of radioactive iodine 123. We recently encountered a patient who had factitious thyrotoxicosis in whom a technetium Tc 99m pertechnetate thyroid scan helped to establish the diagnosis.
Report of a Case.
—An 18-year-old woman was referred to the Ohio State University Hospitals, Columbus, because she suffered from self-induced vomiting, amenorrhea, and anorexia nervosa of three months' duration. On physical examination, she weighed 39.6 kg, and her pulse rate was 60 beats per minute. There was no goiter, and she was clinically euthyroid despite a serum total thyroxine level of 22 μg/dL and an elevated free thyroxine index that was repeated on several occasions. The thyroid-stimulating