Neck Pain and Symptomatic Hypothyroidism: An Atypical Presentation of Subacute Thyroiditis

Subacute thyroiditis (SAT) is a rare form of thyroid disease characterized by fever, neck pain, and dysregulated thyroid hormone levels. It is caused by the post-viral inflammation and destruction of thyroid follicles. Patients typically present with symptoms of hyperthyroidism, as stored thyroid hormone is released into the blood. In this case, we describe a 34-year-old female who presented to the clinic complaining of neck pain and a headache for two days. She endorsed fatigue, myalgias, dizziness, and constipation but denied any fever. She reported only minimal pain relief with ibuprofen and denied a history of recent illness. On exam, she was afebrile and normotensive. Her physical exam was notable for neck tenderness over the right lobe and isthmus of the thyroid, thyromegaly, and a palpable thyroid nodule. Her complete blood count showed no sign of infection or hematologic abnormality, but her thyroid studies showed an elevated thyroid stimulating hormone of 2.1 mIU/L and a decreased thyroxine (T4) level below 0.01 ng/dL. The laboratory results, history, and physical exam led to the diagnosis of the hypothyroid stage of subacute thyroiditis. She was initially treated with ibuprofen 600mg without resolution of her symptoms. She was then treated with prednisone 40mg with symptom relief. This case highlights an atypical presentation of subacute thyroiditis and adds a new presentation to the discussion for patients with this condition.