Autism Spectrum Disorder With Iodine Deficiency Hypothyroidism in a 6-Year-Old Boy

This case study reports on a 6-year-old boy with autism spectrum disorder (ASD) in Japan who developed iodine deficiency hypothyroidism due to extreme picky eating. Despite Japan's high iodine diet, the boy's limited intake of foods like white rice and specific beverages led to deficiencies in iodine, vitamin D, copper, and zinc. His thyroid function was severely impaired, with elevated thyroid-stimulating hormone (TSH) and low free-thyroxine (fT4) levels. Initial treatment with potassium iodide and levothyroxine was unsuccessful due to his inability to take medications, necessitating hospitalization. A multidisciplinary approach, including the use of a token economy method, improved his nutritional status and thyroid function. Post-discharge, his condition stabilized with the introduction of bottled tea containing kelp, which provided necessary iodine. Although his physical growth improved, his psychiatric symptoms and picky eating persisted. The study highlights the challenges of managing nutritional deficiencies in children with ASD and the importance of flexible treatment strategies.