From Balding to Lustrous Locks: Levothyroxine Therapy’s Transformative Impact on Hair Loss in Juvenile Hypothyroidism

A 13-year-old girl was referred to the endocrinology outpatient clinic with chief complaints of significant hair loss leading to balding and poor height gain noted since the age of 5 years. She was born full term with a normal birth weight and had achieved all appropriate developmental milestones. Physical examination (Fig. 1) revealed a pulse of 56 beats per minute, height of 102 cm [<3rd percentile, height standard deviation score (Ht SDS) = -6.92], and weight of 22 kg. She had dry skin, facial puffiness, and a protuberant abdomen. There was diffuse hair loss involving the frontal, temporal, and occipital areas of the scalp with no scarring. Hair loss was noted in the lateral one-third of the eyebrows as well. Her thyroid function tests showed a thyroid stimulating hormone (TSH) level above 100 mIU/mL with low T4 and T3. The bone age was suggestive of 5 years. Antithyroid peroxidase (anti-TPO) testing was not done as it was not available at our center. She was diagnosed with juvenile hypothyroidism and was initially treated with 25 µg of levothyroxine, which was escalated to a full replacement dose after 2 weeks. Two months later, during the follow-up visit (Figs 2A and B), the child was more active and cheerful, facial puffiness had reduced, and there was substantial improvement in hair growth as well. Repeat thyroid function tests showed a TSH level of 1.51 mIU/mL with normal T4 and T3.