Background: Acute suppurative thyroiditis (AST) is a rare, life-threatening thyroid infection characterized by a tender neck mass and fever. As these features are shared with self-limited subacute thyroiditis (SAT), it is important to differentiate between the two disorders.
Patient findings: We report a case of AST in a 21-year-old woman who presented with steadily worsening throat pain for 3 weeks, a tender left neck mass, and thyrotoxicosis. She was initially given prednisone for treatment of presumed SAT but then it acutely worsened. Fine needle aspiration yielded pus on gross examination, and she required intubation and emergent surgical drainage to maintain her airway. Culture of the abscess isolated Streptococcus F and Porphyromonas, a gram-negative intracellular anaerobe not previously reported to cause AST. She improved quickly after surgery, developed transient hypothyroidism that did not require treatment with thyroid hormone, and is currently euthyroid. An abnormal piriform sinus fistula was identified on the left using an esophagram.
Summary: AST may be difficult to clinically differentiate from SAT. Fine needle aspiration revealing pus, culture yielding bacteria or fungi, abscess on ultrasonography and computed tomography, and left-sided predominance are important in the diagnosis of AST.
Conclusions: AST should be considered in any patient with SAT who does not rapidly improve following institution of steroids. Further, the presence of thyrotoxicosis does not eliminate AST as an initial diagnosis.