Myxedema Coma due to Hashimoto Thyroiditis: A Rare but Real Presentation of Failure to Thrive in Infancy

Abstract

Background: Hashimoto thyroiditis (HT) is uncommon in infancy, and myxedema coma (MC) is even less common. While prior reports have documented these entities separately, to our knowledge, MC in combination with HT has not been reported before in this age group. Methods/Results: A 10-month-old female presented with ptosis, lethargy, dysphagia, and failure to thrive (FTT). She developed hypotension, bradycardia, hypothermia, and apnea requiring intubation. Initial thyroid-stimulating hormone was 422 μIU/mL, and free thyroxine was < 0.5 ng/dL, despite the presence of a normal thyroid newborn screen (NBS). Of note, sepsis workup was unremarkable. With the diagnosis of MC, treatment with intravenous levothyroxine was initiated, although after hydrocortisone administration to avert the possibility of an adrenal crisis, despite a random cortisol of 16.4 μg/dL. Based on positive thyroid antibodies suggesting HT, autoimmune workup later revealed positive acetylcholinesterase antibodies consistent with a diagnosis of ocular myasthenia gravis. Conclusion: MC may be a cause of altered mental status in infancy and may simultaneously be associated with FTT on presentation. With the presence of a normal thyroid NBS, autoimmunity should be entertained as the etiology of profound hypothyroidism, as positive thyroid antibodies may prompt an exploration for coexisting diseases which may explain other presenting features.

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

“…Therefore, the diagnosis could easily be missed. So far, to the best of our knowledge, there have only been five children reported to have myxoedema coma (Table ) . Our patient was one of the two youngest children reported.…”

“…Our patient was one of the two youngest children reported. Central hypothyroidism was diagnosed in two children, while the other three children had autoimmune thyroiditis . Myxoedema coma was an initial presenting symptom of hypothyroidism in four patients .…”

“…Regarding myxoedema coma treatment, there has been no consensus guideline for children. Most studies in children used intravenous thyroxine as an initial treatment to rapidly raise serum T4 and avoid the problem of poor enteral absorption . Only one reported paediatric patient used combined intravenous L‐thyroxine and liothyronine .…”

“…So far, to the best of our knowledge, there have only been five children reported to have myxoedema coma ( Table 1). [1][2][3][4][5] Our patient was one of the two youngest children reported. Central hypothyroidism was diagnosed in two children, 2,3 while the other three children had autoimmune thyroiditis.…”

“…Most studies in children used intravenous thyroxine as an initial treatment to rapidly raise serum T4 and avoid the problem of poor enteral absorption. [1][2][3]5 Only one reported paediatric patient used combined intravenous L-thyroxine and liothyronine. 1 However, both intravenous forms of L-thyroxine and liothyronine were not available in our country.…”