Subacute thyroiditis post COVID-9 vaccinations

ABSTRACT

Background: Subacute thyroiditis is being frequently seen after Covid infection as the cases of many other viral infections. Patients classically complain of symptoms of thyrotoxicosis mainly palpitations and sweating but with associated tenderness in neck with or without fever. Subacute thyroiditis has seldom been seen after viral vaccinations. We present a case series of subacute thyroiditis which presented after administration of the COVID-19 vaccine. Material(s) and Method(s) Case 1 A 28-year-old female without previous medical problems, presented to the clinic for sore throat, palpitations and dizziness . No recent history of any upper respiratory tract infection or pregnancy. The patient received her second dose of Pfizer/BioNTech mRNA vaccine for COVID-19 2 weeks earlier. Thyroid function testing was done and revealed TSH 0.001, fT4 3.29, fT3 6.8. Her TPO antibody, thyroglobulin antibodies and Trab were negative. Technetium-99m pertechnetate scan revealed diffuse thyroiditis. The patient was prescribed prednisone 20 mg daily. She reports rapid improvement of her symptoms and prednisone treatment was given for 3 weeks then stopped. Repeated tests showed normal TSH 10 days after stopping steroids. Case 2 A 49-year-old female with the history of V Leiden mutation and repetitive abortions presented to the clinics on May 25, 2021 for the complaint of unintentional weight loss of 6 kg in 20 days and palpitations, preceded by fever and neck pain at the end of April. The patient noted that she was vaccinated with her second dose of Sinopharm vaccine on the 6th of April 2021. Thyroid function test revealed a thyrotoxic profile TSH 0.005, fT4 42, fT3 9,02. With negative thyroglobulin antibody, TRAb. CRP 60 , . Thyroid Ultrasound showed a diffuse heterogenous echtexture of the thyroid. A fever work up was done to rule out other infectious causes including Salmonella and Brucella, all were negative. The patient was prescribed prednisone 40 mg daily and propranolol 10 three times daily, gradually tapered over one months. Her Symptoms resolved and her follow up tests showed normal tsh and CRP Result(s) Discussion: Subacute thyroiditis is usually associated with upper respiratory tract infections including Covid -19 infection. This can be explained by T cells cross reacting between the virus and the thyroid cells. Moreover, De Quervain thyroiditis following viral vaccines has been reported influenza vaccines. Thyroiditis has not been described until now as a frequent side effect of Covid vaccine. So we presented the cases of a 28 and 49- year-old females who has presented with cases of subacute thyroiditis after receiving respectively the Pfizer mRNA vaccine and Sinopharm vaccine for COVID-19. Conclusion(s) Conclusion: Subacute thyroiditis after Covid-19 vaccine is rare but may be underreported. Further investigations are required to evaluate predisposing factors to De Quervain thyroiditis following Covid-19 vaccine.