Myxoedema coma in a 2‐year‐old girl with untreated congenital hypothyroidism: Case report and literature review

Initial low‐dose oral levothyroxine in a child with Down syndrome, myxedema, and cardiogenic shock

“…Still, the dosage is in the vicinity of the recommended dose of 2 μg/kg for children in this age when treated for common hypothyroidism. Likewise, the doses used by Zhu et al who used 4 μg/kg/day for a 6‐year‐old child and Wankanit et al who used around 7 μg/kg/day for a 2‐year‐old child are similar to the dosage recommended for the ages of the children they treated, and slightly higher than the one we initially chose.…”

“…One controversy is whether to use high starting doses of thyroid hormones, or considerably lower doses . Secondly, intravenous administration is recommended as uptake can be compromised by intestinal edema, but other authors argue that oral preparations work, also in children . Thirdly, liothyronine (LT3) is often recommended along with LT4 as the peripheral conversion of LT4 into the more active form LT3 is believed to be compromised as well …”

“…To our knowledge, guidelines on the treatment of myxedema in children are lacking and there are no controlled studies. Five published cases, including the case mentioned above, are compiled in a recent report where all children had altered mental status, and two of them had pericardial effusion . In the comprehensive guidelines from the American Thyroid Association (ATA), myxedema in adults is treated with high doses of intravenous thyroxine (200‐400 μg or higher) .…”

“…To our knowledge, there are only two very recent reports on children with myxedema treated with oral preparations, and neither was published to guide us at the time our patient was treated. Zhu et al successfully treated a 6‐year‐old child with an initial dose of 4 μg/kg/day, and Wankanit et al treated a 2‐year‐old patient with 6.8‐7.3 μg/kg/day . The remaining four patients in the review by Wankanit were successfully treated with intravenous thyroxine in doses 3‐10 μg/kg/day …”

“…Zhu et al successfully treated a 6‐year‐old child with an initial dose of 4 μg/kg/day, and Wankanit et al treated a 2‐year‐old patient with 6.8‐7.3 μg/kg/day . The remaining four patients in the review by Wankanit were successfully treated with intravenous thyroxine in doses 3‐10 μg/kg/day …”