Etiology of Hyperthyroidism and Evidence of a Geographic Variation in Frequency of Painless Thyroiditis
- 1. Kamijo Thyroid Research Institute, Kamijo Thyroid Clinic, Japan
CITATION
Kamijo K (2018) Etiology of Hyperthyroidism and Evidence of a Geographic Variation in Frequency of Painless Thyroiditis. JSM Thyroid Disord Manag 3(1): 1015.
LETTER TO THE EDITOR
The prevalence of painless thyroiditis may become a controversy in clinical thyroidology. Nicolai, et al. [1], found the disorder in 10% to 20 % of their cases of hyperthyroidism. From a review of the subject, Woolf [2] agreed that painless thyroiditis was relatively common, occurring in 3.6% to 23% of all cases of hyperthyroidism. Similarly, in a review of 3,674 patients with hyperthyroidism seen in my thyroid clinic between 1996 and 2015 in Sapporo, Japan, we found 643 patients with painless thyroiditis as the causal mechanism, an incidence of 17.5% (Table 1). This is compatible with that Tajiri, et al.[3], in Japan and is contrast to the rarity (0.51% - 2.4%) reported from authors [4,5]. Graves’ disease was found in 2,601(70.8%) of the 3,674 hyperthyroid patients and subacute thyroiditis occurred in 367(10.0%) cases. Toxic nodular goiter was seen in 63(1.7%) of the patients. The present study suggests a geographic variation in painless thyroiditis.
Table 1: Frequency of 3,758 patients with thyrotoxicosis at initial visit in our clinic.
Graves’ Disease | Painless Thyroiditis | Subacute Thyroiditis | Toxic Nodular Goiter | Total | |
Male | 400 | 69 | 27 | 5 | 501 |
Female | 2,201 | 574* | 340 | 58 | 3,173 |
2601 (70.8%) | 643 (17.5%) | 367 (10.0%) | 63 (1.7%) | 3,674 |