ESPE Abstracts

Background: Thyrotoxicosis in neonates is a life-threatening condition that can be associated with lasting neurologic problems. Most cases are seen in neonates born to mothers with Graves’ disease in which thyroid stimulating immunoglobulin (TSI) is transferred to the foetus and results in hyperthyroidism. Hypothyroidism due to topical iodine use has been reported in neonates, but thyrotoxicosis has never been described in this age, while in adults is a known entity. We hereby describe a first case of topical iodine induced thyrotoxicosis in a new-born with giant omphalocele.

Case presentation: A female baby born at 34 weeks of gestation with multiple congenital abnormalities, including a giant omphalocele, persistent ductus arteriosus, and thoracolumbar scoliosis. In preparation for surgery omphalocele was covered with daily betadine dressings containing potassium iodide (KI). On day 3rd of life, evaluation of thyroid revealed suppressed TSH at 0.59 mcIU/ml (NL 0.73–4.60 mcIU/ml) and elevated free thyroxine (FT₄) at 5.63 ng/dl (NL 0.58–1.64 ng/dl) that subsequently lead to symptomatic hyperthyroidism with tachycardia and hypertension. Maternal history was negative for thyroid disease and thyroid antibodies were negative. Therefore we presumed that hyperthyroidism was secondary to KI dressing. On day 5th of life the KI dressing was changed to SilvaDene (iodine free) dressing, and propranolol 0.01 mg/kg per dose was started to treat hypertension and tachycardia. Serial daily thyroid tests were monitored. Thyroid status gradually improved with complete resolution in 8 days after removal of KI dressing (FT₄ 1.26 ng/dl, TSH 2.21 mcIU/ml, and FT₃ 2.34 pg/ml). Propranolol discontinued.

Conclusion: Hypothyroidism due to topical iodine use in omphalocele has been described in new-borns. Novel insight: to our knowledge, this is the first case of topical iodine induced neonatal thyrotoxicosis. This case demonstrates the critical need to monitor thyroid status in new-borns treated with topical iodine, in order to identify thyroid abnormalities and to consider alternative methods.