COVID-19 Infection Causing Atypical Thyroiditis

Introduction: Coronavirus disease 2019 (COVID-19) has caused significant health burden across the world. Identification of factors contributing to severe disease is important to enable stratification of risk, optimize the reallocation of hospital resources, and guide public health recommendations and interventions. Subacute thyroiditis is an inflammatory thyroid disease characterized by neck pain and is usually preceded by an upper respiratory tract infection. It may be caused by a viral infection or a post-viral inflammatory reaction, and many viruses have been linked to the disease. We present case of atypical thyroiditis associated with COVID-19 infection. Case Report: 27-year-old female with no significant past medical history apart from recent COVID-19 infection is referred to endocrinology for evaluation of abnormal thyroid function test. Patient states around three months ago she was experiencing the symptoms like unintentional weight loss, nausea, palpitation, insomnia, anxiety, fatigue similar to symptoms she experienced 9 years ago while she was pregnant with her daughter so she thought she is pregnant again and visited her gynecologist. But patient had pregnancy test was done and she was found to be negative but her thyroid function test showed low TSH 0.32mIU/ml (0.47-4.68mIU/ml). Patient states around same time she was diagnosed with COVID-19 infection and she lost 5 pounds during that time but even after recovery from the infection she continued to lose weight and lost a total of 18 pounds in 3 months. Patient states during the time of COVID-19 infection she was having difficulty swallowing and painful swallowing but following infection patient denied any current difficulty swallowing or breathing, headache, vision changes, cold or heat intolerance, diarrhea or constipation, tremors, proximal muscle weakness, bulging of her eyes. Patient continue to have regular monthly menstrual cycles. Three months following infection patients repeat thyroid function tests were done and it showed normal TSH 0.56mIU/ml(0.47-4.68mIU/ml),free T4 1.05ng/dL(0.78-2.19ng/dL) and negative thyroid antibodies like TSI index<1.0, Thyroid peroxidase Antibodies 1.4 IU/mL, Thyrotropin Receptor Ab <1.00 IU/L. Patient also had normal thyroid ultrasound. Patient had complete resolution of hyperthyroid symptoms and did not require any medications. Conclusion: In conclusion, physicians should be engaged in close monitoring of thyroid disease in patients with suspected COVID-19, for timely detecting signs of disease progression. Finally, the presence of thyroid disease shall be regarded as an important factor in future risk stratification models for COVID-19.