Subacute thyroiditis: a review of 105 cases.

A retrospective review of 4023 thyroid scans performed at the Royal Adelaide Hospital in the five years to February 1987 identified 105 cases of subacute thyroiditis. Subacute thyroiditis accounted for 9.9% of subjects scanned for hyperthyroidism. Eighty-four percent had painful thyroiditis, 6% postpartum thyroiditis, and 10% painless thyroiditis. Follow-up was obtained in 68% of cases, and 11% were taking thyroxine, probably indicating long-term hypothyroidism. Apart from the presence of antibodies in post-partum thyroiditis, no other factor was identified which predicted the development of long-term hypothyroidism. As subacute thyroiditis is a common cause of hyperthyroidism in our community, the authors believe all people with hyperthyroidism should have a thyroid scan unless they have distinctive features of Graves' disease.