What is Subacute (Nonsuppurative or
'de Quervain's') Thyroiditis?

This condition was first described in 1904. It is caused by a viral infection characterised by an enlarged tender thyroid with fever, muscle aches and malaise. There is a phase of thyroid overactivity followed by under activity and finally the thyroid function returns to normal (Euthyroid). The disease is usually self-limiting.

The diagnosis is made by the clinical findings. During the acute phase the serum T3 and T4 concentrations are elevated, these then become subnormal in those patients who enter a hypothyroid phase. There is a high blood sedimentation rate (ESR) and evidence of no uptake on the thyroid nuclear scan.

Treatment is directed at controlling the pain and aspirin is effective; rarely a short course of steroids is needed. In some patients who have a significant hypothyroid phase treatment with thyroxine is necessary, but rarely needs to extend beyond 3 to 4 months. There is no indication for surgery unless fine needle aspiration raises doubts about the diagnosis.