Endocrine Abstracts

Introduction: Graves’ disease is an autoimmune disease that leads to a generalized over activity of the entire thyroid gland (hyperthyroidism). It is caused by TRAb thyrotropin receptor antibodies (TRAb), which bind to receptors on the surface of thyroid cells and stimulate those cells to overproduce and release thyroid hormones. Subacute thyroiditis is presumed to be caused by a viral infection or a postviral inflammatory process. It is a self-limited thyroid condition associated with a triphasic clinical course of hyperthyroidism, hypothyroidism, and return to normal thyroid function.

Case: In this article we present a case of a 52-years old women diagnosed with subacute thyroiditis, in the hyperthyroid phase. She was presented with fever up to 38°C, pain and tenderness on the palpation of thyroid, weakness, mild tachycardia and palpitations. Thyroid Ultrasound resulted with enlargement and heterogenous structure in both lobes, difuse hypoechoic parts with no vascularization in the right lobe, but mildly hyper vascularization in the left one. Laboratory findings: TSH=0.005mIU/ml (n=0.27-4.7), FT3=25.39pg/ml (n=3.1-6.8), FT4=59.53pg/ml(n=12-22), ESR=72mm/h (n=3-20), PCR=11.15(n=0.0-5.0), TRAb=13.24IU/ml (n<1.22). Covid-19 tested negative. The thyroid scan showed an enlarged gland with heterogeneous trapping. She was treated with prednisone 35 mg/d with tapering dose down to 5 mg/day in 4 weeks, beta-blocker and omeprazole. The pain and fever was resolved after 3-4 days. Four weeks later the inflammatory tests resulted negative. She was feeling much better, but she continued to have weakness. In the follow –up after 6 weeks the patient complained dyspnea. Total blood count was normal, ESR=29 mm/h, PC r=2.29 other renal and liver tests normal. Thoracic scan ruled out any pulmonary disease. EKG revealed tachycardia. TSH=0.005 mIU/ml, FT4=100 pg/ml. The patient was started on treatment with methymasole 40 mg / day. Follow-up in 4 weeks, clinically stable, FT3= 6.86 mIU/ml, FT4=17.18 mIU/ml, TRAb=10 IU/ml, ESR=24 mm/h, PC r=2.0. Thyroid ultrasound continued with heterogenic structure, normal vascularization. The treatment with methymasole was tapered down to 20 mg/day. Follow up at 3 months.

Conclusions: The development of Graves’ disease and subacute thyroiditis simultaneously is an uncommon condition and only a few cases have been reported. The diagnosis of Graves’ disease in these patients is always difficult because of atypical signs and symptoms and the unclear onset time. The causes of the Graves’ disease that followed subacute thyroiditis are still unknown. However, Graves’ disease should be suspected when a high blood level of thyroid hormone and TRAb persists after subacute thyroiditis.