Hypothyroidism in Children and Adolescents

When the thyroid gland stops working despite being normal in the newborn period it is called ‘acquired’ hypothyroidism. Hashimoto’s thyroiditis  (also called autoimmune thyroiditis) is the most common cause of acquired hypothyroidism in children and adolescents.

It usually develops after the first few years of life. It can present with or without goitre. Hence thyroid hormone levels are to be done if any symptoms of hypothyroidism or history of thyroid disease in the family.

Less common causes of hypothyroidism in children include:

• Thyroiditis, temporary inflammation of the thyroid that may be caused by a viral or bacterial infection.
• Surgical removal of the thyroid gland
• Radiation treatment that destroys or injures the thyroid gland.
• Medicines like lithium, amiodarone, and oxcarbazepine that can prevent the thyroid gland from working
• Too much or too little iodine, which can prevent the thyroid gland from working normally.
• Damage to the pituitary gland. The pituitary (the “master gland”) in the brain tells the thyroid how much hormone to make.

What Are The Symptoms of Hypothyroidism?

Two important symptoms in children are:

• Slowing of height – an important early sign of hypothyroidism in children and
• Delayed puberty in children.

Others could be the presence of Goiter, poor scholastic performance, fatigue (being more tired than expected), constipation, increased sensitivity to cold, dry skin, brittle hair, irregular and/or heavy menstrual periods and weight gain.

How Is Hypothyroidism Diagnosed?

1. Measurement of thyroid hormones in the body-T3, T4, TSH, FT4. In hypothyroidism T3, T4, FT4 are low and TSH is high.

• Thyroid auto-antibodies – the immune system makes antibodies against thyroid proteins (called thyroid Peroxidase and thyroglobulin) and the antibody levels may be measured to confirm the diagnosis of Hashimoto’s disease.

How is it Hypothyroidism Treated?

The goal is to bring the T4 and TSH back to the normal range and restore the body’s normal functions. The majority of patients can achieve normal thyroid hormone levels by taking levothyroxine.

The ideal way to take levothyroxine is on an empty stomach, at least 45 to 60  minutes before eating. Avoid missing doses.

Calcium or iron supplements or vitamins should not be taken at the same time as levothyroxine

How should the follow up be?

A thyroid hormone levels should be checked 6 to 8 weeks after starting levothyroxine (T4) or after any change in levothyroxine dose. The goal of treatment is to keep the TSH and FT4 in the normal range.

Older children can have these levels checked every 3 months until they have finished growing and going through puberty. Then it could be checked once in 6 months.

What Can You Expect Over The Long Term?

The dose of levothyroxine often changes during childhood and adolescence due to growth and change in metabolism. There are no restrictions on everyday life and activities. Patients with hypothyroidism can and should have productive and rewarding lives.