HISTORY Mdm T, a 49 years old Chinese woman presented with giddiness and fever for 10 days. She was previously well. Prior to this presentation, she was seen in a private hospital twice and was told that the fever was not due to dengue. She was given antibiotic but her condition did not improve
PHYSICAL EXAMINATION Her temperature was 37.4°C, BP 130/70 mmHg, pulse 72/min. A small diffuse goitre was noted, and the left lobe was tender on palpation. There was no palpable cervical lymph node and no clinical signs of hyperthyroidism.
In view of the physical finding, an ESR and a thyroid function test (TFT) were done, the results were:
ESR: 78 mm/h (normal: <21)
TFT: Free T4 54.5 pmol/L (normal: 9-25), TSH <0.01 mIU/L (normal: 0.4-4.7)
QUESTIONS:
What is the diagnosis and differential diagnosis?
What is the appropriate management of this condition?
What is the long-term outcome of this condition?
ANSWERS:
The presence of fever and thyroid pain and tenderness, biochemical hyperthyroidism, and high ESR together make the diagnosis of subacute thyroiditis most likely.1,2 Subacute thyroiditis is also known as de Quervain’s thyroiditis and granulomatous thyroiditis. It is believed to be caused by viral infection. In this condition, despite the marked release of thyroid hormones from the damaged thyroid follicular cells, clinical hyperthyroidism occurs only in 50% of patients, and the thyrotoxic symptoms are not serious and are transient. Because of this, it can be missed clinically. Furthermore, her thyroid pain was quite mild. In some case, the thyroid pain can be absent, and fever is the only manifestation.3 In acute suppurative thyroiditis, ESR is also elevated but the thyroid function is normal. Postpartum thyroiditis and Hashimoto’s thyroiditis may have a brief period of thyrotoxicosis but they do not have thyroid pain, and ESR is normal.
The treatment of subacute thyroiditis is essentially symptomatic, targeting the thyroid pain with non-steroidal anti-inflammatory agents or prednisolone (taper over 4-6 weeks) if the symptom is prolonged or severe.2
Recurrence of subacute thyroiditis can occur but is rare (about 2%).1 The biochemical hyperthyroidism may persist for several months, but eventually return to normal in about one year. However, in long-term follow-up study, hypothyroidism was documented in about 15% of affected individuals.4
REFERENCES
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