Abstract
Introduction: The thyroid gland is highly resistant to infection due to a robust blood supply, good lymphatic drainage, and high iodine concentration. Suppurative thyroiditis (ST) often presents with fever, tachycardia, leukocytosis, tenderness, and euthyroid labs. However, when ST occurs with thyrotoxicosis, it can meet criteria for thyroid storm, which presents a diagnostic dilemma. Clinical Case: A 17 year old female with family history of Graves’ disease presented to the ER with a sore throat. She was diagnosed with viral pharyngitis and treated with dexamethasone. Over the next 2 weeks, she developed fatigue, body aches, nausea, vomiting, and chills. She returned to the ER and was found to have tachycardia, hyperthyroidism [free T4 5.64 ng/dL (0.8 - 2.0 ng/dL), TSH <0.015 uIU/mL (0.5 - 4.5 uIU/mL)], and WBC 11 k/uL (3.5 - 11.5 k/uL). She was prescribed atenolol and referred to Endocrinology. Three days later she developed fever, diaphoresis, ear pain, vomiting, and abdominal pain. In the ER, she was febrile to 101.2°F with a heart rate (HR) of 117 BPM. Labs showed a free T4 6.14 ng/dL, TSH <0.015 uIU/mL, and WBC 20 k/uL. She was treated with methylprednisolone, propylthiouracil, and labetalol with improvement and transferred for concern of impending thyroid storm. Exam showed left-sided thyroid enlargement with tenderness. Thyroid ultrasound showed an enlarged heterogenous left thyroid lobe with 2 nodules, one 25 x 33 x 21 mm heterogenous and one 19 x 11 x 19 mm homogenous, without discrete abscess. That night she developed vomiting, hand tremors, HR in the 130’s BPM, fever to 104.1°F, and a headache. Treatment was initiated with methimazole, SSKI drops, propranolol, and dexamethasone. Symptoms improved save persistent neck tenderness and dysphagia. CT neck demonstrated a left-sided 25 x 17 x 90 mm abscess with concern for 4(th) branchial apparatus abnormality. She underwent incision and drainage with drain placement. Cultures grew Streptococcus anginosus and Fusobacterium necrophorum. Broad spectrum antibiotics were started and later narrowed to ampicillin-sulbactam. Betablockers and methimazole were discontinued and thyroid labs nearly normalized by discharge [T4 11.8 mcg/dL (4.5-11.5 mcg/dL), free T4 2.0 ng/dL (0.8-2 ng/dL), and total T3 78 ng/dL (100-210 ng/dL)]. Thyroid auto-antibodies were negative. Discussion: In patients with ST, only 11% present with hyperthyroidism. Current thyroid storm scoring systems are sensitive but not specific so an acute bacterial infection with thyrotoxicosis can easily meet criteria. While ultrasound is standard for assessing for thyroid abscesses, in the setting of high clinical suspicion, further imaging with contrasted neck CT is warranted.