Atypical subacute thyroiditis mimicking tuberculosis: a case report and review of literature

Subacute thyroiditis is a self-limiting condition caused by thyroid inflammation. It usually presents with fever, neck pain and symptoms of thyrotoxicosis. Atypical presentations without neck pain are rare and often lead to misdiagnosis, especially in low-resource settings.

We report a case of atypical subacute thyroiditis in a man of Middle Eastern descent that was initially misdiagnosed as tuberculosis, with lymphoma, painless sporadic thyroiditis, and laryngeal malignancy being differentials. The patient, a 41-year-old male, presented with progressively worsening fevers, night sweats, and weight loss, with thyroid cartilage thickening and tenderness on physical exam. He was diagnosed with subacute thyroiditis through Doppler ultrasound scanning of the thyroid gland, elevated inflammatory markers, and the presence of antibody-negative hyperthyroidism on his biochemical thyroid screen. Symptomatic relief was provided with salicylate and prednisolone. The patient experienced transient asymptomatic hypothyroidism 4 months after disease onset, which was not treated. Euthyroidism was achieved 6 months after symptom onset.

Subacute thyroiditis is a rare disease thought to be postviral in origin. It generally presents with fever, neck pain, and signs of thyrotoxicosis and evolves in three phases-a hyperthyroid, hypothyroid, and euthyroid phase. Atypical subacute thyroiditis without neck pain is even rarer; therefore, clinicians should maintain a high index of suspicion for thyroid disorders whenever symptoms suggestive of thyrotoxicosis are encountered, and should always consider thyroid abnormalities when investigating weight loss or persistent fevers in an African setting.