Hypothyroidism in children can be congenital or acquired. Thyroid hormone is essential for the development and functioning of the brain and body. Undiagnosed hypothyroidism can lead to significant problems with neurodevelopment and intellectual disability.
Congenital hypothyroidism is where the child is born with an underactive thyroid gland. This occurs in around 1 in 3000 newborns. It can be the result of an underdeveloped thyroid gland (dysgenesis) or a fully developed gland that does not produce enough hormone (dyshormonogenesis). Very rarely it can be the result of a problem with the pituitary or hypothalamus. This usually occurs without any other problems and the cause is not clear.
Congenital hypothyroidism is screened for on the newborn blood spot screening test. Where it is not picked up a birth, patients can present with:
- Prolonged neonatal jaundice
- Poor feeding
- Increased sleeping
- Reduced activity
- Slow growth and development
Acquired hypothyroidism is where a child or adolescent develops an underactive thyroid gland when previously it was functioning normally.
The most common cause of acquired hypothyroidism is autoimmune thyroiditis, also known as Hashimoto’s thyroiditis. This causes autoimmune inflammation of the thyroid gland and subsequent under activity of the gland. It is associated with antithyroid peroxidase (anti-TPO) antibodies and antithyroglobulin antibodies. There is an association with other autoimmune conditions, particularly type 1 diabetes and coeliac disease.
This can lead to symptoms of:
- Fatigue and low energy
- Poor growth
- Weight gain
- Poor school performance
- Dry skin and hair loss
Children will be managed and followed up by a paediatric endocrinologist. Investigations include full thyroid function blood tests (TSH, T3 and T4), thyroid ultrasound and thyroid antibodies.
Levothyroxine orally once a day is used to replace the normal thyroid hormones. Doses are titrated based on thyroid function tests and symptoms.
Last updated January 2020