Background: Hypothyroidism is associated with impared growth and pubertal delay. However, there are female patients with untreated acquired hypothyroidism and paradoxical precocious pubertal signs, which include thelarche, galactorrhoea and menarche. These girls do not have axillary and pubic hair development. The exact mechanism for this pseudoprecocious puberty is not clear. The most probable explanation is that high levels of TSH act through the FSH receptor and cause gonadal stimulation.
Clinical Case: A 10-year old girl was admitted to Endocrinology department with complains of short stature, fatigue, loss of appetite, constipation and cold intolerance. Physical examination showed: pale and dry skin, puffy face, height 123 cm (<3th percentile), body weight 22 kg (<3th percentile), blood pressure - 88/56 mmHg, pulse 59 beats/ min. Thyroid gland was not tender but the size was normal. Breast development was Tanner stage III IV without galactorrhoea or other pubertal signs. Bone age was 7 years and 10 months. Laboratory data showed: Haemoglobin-10.5 g/dl, Cholesterol- 7.02 mmol/l (normal <4.40), Tryglycerides 1.5 mmol/l. Hormonal evaluation revealed: FT4- <4.50 pmol/l (normal 10.8 22.7), TSH 1261 mIU/l (normal 0.40-4.00), Anti-Thyroglobulin Ab- 676 IU/ml (normal <35), Anti- Thyroid Peroxidase Ab 553 IU/ml (normal <40), pubertal levels of FSH and prepubertal levels of LH and prolactin. Ultrasound of the thyroid showed typical changes for autoimmune thyroiditis. Echocardiogram revealed moderate pericardial effusion. Initial treatment was with increasing doses of L-Thyroxin and decreasing doses of corticosteroids. Follow up showed improvement of patient's physical condition and hormonal status, as well as decrease in the size of her breasts.
Conclusion: Early recognition of thyroid dysfunction is very important because untreated hypothyroidism has negative effect on growth and metabolism and may also cause pseudoprecocious puberty in girls. Hormonal replacement with L-Thyroxin leads to a resolution of all these complications.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology