Recently, Liel and Alkan1 reported 2 cases of thyrotoxicosis in young adults who had used iodine-containing preparations to purify water during backpacking trips to Central and South America ("travelers' thyrotoxicosis"). Interestingly, in both cases, serologic test results were positive for thyroperoxidase antibodies, and 1 patient had a family history of immune thyroid disease. The authors postulated a form of iodide-induced thyrotoxicosis, reflecting an inadequate response to an iodide excess in association with a presumed preexisting, asymptomatic, autoimmune thyroid disease. However, this underlying thyroid disease was not serologically or histologically documented in either of the 2 patients.
Mueller B, Diem P, Bürgi U. "Travelers' Thyrotoxicosis" Revisited. Arch Intern Med. 1998;158(15):1723. doi: