Severe headache as the initial manifestation of painless thyroiditis: a pediatric case report.

Painless thyroiditis is a potential cause of thyrotoxicosis, typically presenting with weakness, fatigue, irritability, palpitations, and tremors; however, headache is an uncommon manifestation. Herein, we report two pediatric cases of painless thyroiditis in which headache was the initial presenting symptom. Two 14-yr-old boys presented to our emergency department with chief complaints of severe migraine-like headaches. They did not exhibit typical symptoms of thyrotoxicosis. Head imaging findings revealed no abnormalities, and blood test results indicated elevated thyroid hormone and suppressed thyroid-stimulating hormone levels. Both patients were diagnosed with painless thyroiditis based on the absence of thyroid pain and increased blood flow on thyroid ultrasonography, and were monitored on an outpatient basis with only symptomatic treatment. One patient experienced palpitations and required treatment with propranolol. Within a few months, thyroid hormone levels normalized spontaneously in both patients, and their headaches improved accordingly. Although the mechanism by which thyroid hormones cause headaches remains unclear, these two cases suggest that thyrotoxicosis may be associated with headaches. Thus, it is important to measure thyroid hormone levels in patients with severe headaches without an obvious cause. Furthermore, early detection of thyrotoxicosis may be possible, leading to appropriate treatment, prediction of the future course of the patient's headache, and relief of the patients' and parents' anxiety levels.