453

EDITORIAL

Silent Thyroiditis in Uncommon Setting

Kumiko Tsuboi

Key words: thyrotoxicosis, pregnancy

(Intern Med 51: 453, 2012)(DOI: 10.2169/internalmedicine.51.6785)

The most common causes of thyrotoxicosis in Japan aresilent thyroiditis and Graves disease. For patients with thy-rotoxicosis present in early pregnancy, both gestational thy-rotoxicosis and undiagnosed Graves disease must be con-sidered. Silent thyroiditis is a rare condition during preg-nancy. Postpartum thyroiditis is a variant of silent thyroiditisthat occurs in the postpartum period, a few months after de-livery, and occasionally as long as 1 year later. The develop-ment of postpartum thyroid disease might be due to suppres-sion of the immune system during pregnancy, with a subse-quent rebound of immune-competence after delivery. It isnot uncommon to find women who have started on theirnext pregnancy within this transient thyrotoxicosis. In this

issue of Internal Medicine (1) Sato et al discuss thyrotoxico-sis in the first trimester of pregnancy with this time frame.Overt thyrotoxicosis has an impact on pregnancy out-

comes and offspring development. Silent thyroiditis, how-ever uncommon in pregnancy, must be differentiated fromGraves disease.

The authors state that they have no Conflict of Interest (COI).

Reference

1. Sato S, Endo K, Iizaka T, et al. A case of painless thyroiditis in avery early stage of pregnancy. Intern Med 51: 475-477, 2012.

Division of Diabetes, Metabolism and Endocrinology, Toho University, JapanReceived for publication October 26, 2011; Accepted for publication October 30, 2011Correspondence to Dr. Kumiko Tsuboi, kumiko@med.toho-u.ac.jp 2012 The Japanese Society of Internal Medicine Journal Website: http://www.naika.or.jp/imindex.html