Myxedema as Presenting Feature of Profound Primary Hypothyroidism in a Toddler

This case study reported an unusual presentation of primary hypothyroidism in a 2-year-old boy, characterized by myxedema, pericardial effusions, and severe biochemical hypothyroidism, despite negative thyroid antibodies. The child, who had a history of lissencephaly and developmental delay, exhibited symptoms such as non-pitting edema and a sallow complexion, but lacked typical signs like cold intolerance or hair loss. His thyroid function tests showed an elevated TSH of 562 mcu/ml and a low FT4 of 0.3 ng/dl. Treatment with levothyroxine was initiated. The study highlighted the importance of recognizing atypical presentations of hypothyroidism in young children to ensure timely treatment and better neurocognitive outcomes.