MANAGEMENT
Thyroid function should be monitored by testing every two to four weeks, dependent on the severity of the patient’s symptoms and rate of progression.1 Often, no treatment is required.1,2
Symptomatic relief of mild thyroid pain can be achieved with NSAIDs or aspirin (2 to 3 g/d). Severe symptoms can be treated with short-term prednisone, which should be tapered and discontinued.1-3 Steroids suppress the inflammatory response, and the dramatic relief of thyroid pain within 24 hours can be diagnostic of SAT.2
During the thyrotoxic phase, β-blockers (propranolol) can alleviate adrenergic symptoms, with the dose tapered once the patient is euthyroid.1-3 Antithyroid medications that directly inhibit thyroid hormone synthesis (eg, methimazole or propylthiouracil) are ineffective due to the lack of T4 and T3 production in the follicular cells after the inflammatory response.2,3
During the transient hypothyroid phase, thyroid hormone replacement may be indicated if the TSH level is markedly elevated or the phase refractory. However, levothyroxine therapy should be low dose (< 100 μg) and not be considered lifelong.2,3
DIFFERENTIAL DIAGNOSIS
During the prodrome, SAT is often misdiagnosed as pharyngitis. Acute suppurative thyroiditis initially may mimic SAT, but the febrile and leukocytic responses are greater, and localized edema, erythema, and tenderness become more evident as the condition progresses.
Painless or silent thyroiditis is distinguished from SAT by the lack of pain or tenderness and a normal ESR in the presence of a similar pattern of thyroid dysfunction. Graves disease presents with symptoms similar to the thyrotoxic phase of SAT, but T3 is usually disproportionately elevated compared to T4, RAIU is elevated, and thyroid antibodies are prevalent.2
CONCLUSION
Primary care providers may encounter SAT at some point, and a level of clinical suspicion must be maintained. Referral to endocrinology may be warranted in some cases; however, textbook cases can often be followed in primary care. Patient education is the foundation of SAT care. Symptomatic treatments may be employed as needed. Fortunately, for most patients, this self-limited disease state rarely leads to complications.
REFERENCES
1. Cooper DS. The thyroid gland. In: Gardner D, Shobeck D (eds). Greenspan’s Basic and Clinical Endocrinology. 9th ed. China: McGraw-Hill; 2011:163-226.
2. Guimaraes VC. Subacute and Riedel’s thyroiditis. In: Jameson JL, De Groot LJ (eds). Endocrinology Adult and Pediatric. 6th ed. Philadelphia: Saunders; 2010:1595-1600.
3. Jameson JL. Disorders of the thyroid gland. In: Jameson JL (ed). Harrison’s Endocrinology. 2nd ed. China: McGraw-Hill; 2010: 62-98.
4. Smallridge RC. Thyroiditis. In: McDermott MT (ed). Endocrine Secrets. 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:289-293.