SAT-464 A Case of Impending Thyroid Storm in a Patient with Subacute Thyroiditis Following an Influenza Vaccine

Abstract

Introduction: Thyroid storm is a rare, potentially fatal condition, affecting 1% of individuals with thyrotoxicosis. Although it can theoretically be seen in any cause of thyrotoxicosis, the most likely underlying etiology is Graves’ disease. The rarity of thyroid storm due to thyroiditis makes the diagnosis challenging as the clinical and biochemical features overlap Grave’s disease. Here we describe a rare case of severe thyrotoxicosis in a woman due to subacute thyroiditis that developed after receiving an influenza vaccine.Case report: A 30 year-old Caucasian female with no known past medical history presented to the ED with worsening sore throat, odynophagia and anterior neck pain. Symptoms began 4 weeks ago prior to presentation, 1 day after receiving an influenza vaccine. Other symptoms included loss of appetite, chills, fever, fatigue, malaise, abdominal pain, diarrhea, palpitations, heat intolerance and 5lbs weight loss. She was treated by her primary care provider for suspected pharyngitis with a course of corticosteroids and antibiotics. Two weeks later, given worsening symptoms, was referred to the emergency room. On exam, she appeared anxious and was tachycardic (124 beats per minute) and tachypneic (28 breaths per minute). She had no lid lag, stare, thyromegaly or thyroid bruit. However, there was significant tenderness on palpation of the anterior neck. Laboratory evaluation was notable for TSH <0.01 uIU/mL (0.39 - 4.0.8), free T4 5.19 ng/dL (0.58 - 1.64), free T3 10 pg/ml (2.53-3.87), ESR 95 mm/hr (0-20) and CRP 9.339 mg/dl (0.0-0.9) consistent with thyrotoxicosis. Given Burh-Wartofsky score of 45, there was a concern for impending thyroid storm. She received hydrocortisone, methimazole and beta blockers and was admitted to the intensive care unit. She responded dramatically to treatment and was discharged within 24 hours on prednisone and metoprolol. The 24-hour radioactive iodine uptake (RAIU) was 2.7% 2 weeks post admission, consistent with a diagnosis of subacute thyroiditis. TSI was negative. Family history was negative for autoimmune disease. She continued on beta blockers with a steroid taper for 8 weeks. Thyroid function tests and inflammatory markers normalized within 3 months.Conclusion:Aside from the described patient, only three other cases of thyrotoxic crisis due to subacute thyroiditis have been reported in the literature. This case underscores the importance of thoroughly investigating the etiology of severe thyrotoxcosis, given the management and prognosis varies depending on underlying cause. Thyroiditis should be considering in the differential diagnosis of thyroid storm in patients who do not have a personal or family history of autoimmunity and present with neck tenderness in the setting of a precipitating event. Subacute thyroiditis is very uncommon after influenza vaccine, there have been 4 reported cases.