A 47-year old lady presented in opd a month back with symptoms of palpitations and high BP recordings at home. She was on levothyroxine 88mcg for hypothyroidism,which was diagnosed in 2008. Thyroid function test revealed low TSH (0.05) with raised FT3 and FT4. Possibility of iatrogenic hyperthyroidism was kept and was asked to stop LT4 and repeat TFT after 1 month. On next visit, her TSH was 0.01 with three times raised FT3,FT4 levels. She had exopthalmos and thyroid gland was mildly enlarged. After admission, Tc99 thyroid scan was done which showed increased tracer uptake in both lobes of thyroid. Also, Anti TPO and TSH receptor antibody (TRAb) came positive. A final diagnosis of Grave’s disease was made and carbimazole was started with propranolol.
This conversion of hypo to hyperthyroidism is rarely documented in literature and is believed to be due to genetic susceptibility.
