Hypothyroidism in Children: Causes, Symptoms, and Treatment

Hypothyroidism is a condition characterized by insufficient production of thyroid hormones. In infants, it can lead to poor feeding and failure to grow, while in older children and adolescents, the symptoms are similar to those seen in adults, but may also include growth failure and delayed puberty, or both.

What is Hypothyroidism in Children?

Hypothyroidism in children is a common endocrine disorder in which a child’s thyroid gland does not produce enough thyroid hormone. A child with an underactive thyroid might face symptoms such as fatigue, weight gain, constipation, slowed growth, and other related issues. The thyroid, a small, butterfly-shaped gland located at the front of the neck just below the Adam’s apple, produces hormones that influence many aspects of your child’s health, including heart rate, energy metabolism (how efficiently the body uses calories), and overall growth and development.

Types and Causes of hypothyroidism

Congenital Hypothyroidism

Congenital hypothyroidism (CH) happens when the thyroid gland doesn’t develop or work properly before birth. It’s a common condition, affecting about 1 in every 2,500 to 3,000 babies. Several factors, such as family history, the child’s physical exam, the severity of hypothyroidism at the time of diagnosis, and the treatment given during the first few years of life, will help the doctor to determine if the condition is inherited and if long-term treatment is needed.

Autoimmune Hypothyroidism: chronic lymphocytic thyroiditis

Acquired hypothyroidism is commonly caused by an autoimmune condition called chronic lymphocytic thyroiditis (CLT). In this condition, the child’s immune system mistakenly attacks the thyroid gland, causing damage and reducing its function. The disorder was first described by Japanese doctor Hakaru Hashimoto, so it is often known as Hashimoto’s thyroiditis. CLT is more common in girls than boys and occurs more frequently in adolescents than in younger children.

Iatrogenic Hypothyroidism

Iatrogenic hypothyroidism is a type of acquired hypothyroidism that happens in children who have had their thyroid gland either destroyed through medical treatment or surgically removed. Without the thyroid gland, the body stops producing thyroid hormones, resulting in iatrogenic hypothyroidism.

Central Hypothyroidism

Central hypothyroidism happens when the brain fails to produce thyroid-stimulating hormone (TSH), which signals the thyroid gland to function. This condition is much rarer than other thyroid-related disorders.

Symptoms of Hypothyroidism may include:

 Fatigue or difficulty tolerating exercise

 Weight gain

 Constipation

 Thin, dry, and coarse hair

 Dry, thickened, and rough skin

 Slow heart rate

 Sensitivity to cold

 Muscle cramps

 Thinning or loss of eyebrows

 A dull facial expression

 Hoarse voice

 Slow speech

 Puffy or swollen face

 Enlarged thyroid causing a goiter-like growth on the neck

 Heavier menstrual flow and cramping in girls and young women

Testing and diagnosis

The diagnostic process starts with a detailed medical history and a physical exam of your child. 

A thyroid function test, which is a blood test, checks the levels of thyroid hormone (T4) and thyroid-stimulating hormone (TSH).

Anti-thyroid antibody tests measure the levels of anti-thyroperoxidase (anti-TPO) and anti-thyroglobulin (TgAb), which are higher in autoimmune hypothyroidism. Unlike the antibody found in Graves’ disease (a form of hyperthyroidism), these antibodies don’t have any active role. Instead, they are used as markers to help diagnose the condition.

A thyroid ultrasound uses sound waves to create an image of your child’s thyroid and nearby lymph nodes.

Who should be tested for Hypothyroidism?

Children with poor growth (unhealthy height to weight ratio)

Children who have received cranial radiation as part of cancer treatments 

Children who are obese (excess weight for their age)

Children with a history of severe brain injury or developmental issues

Anyone showing symptoms of hypothyroidism

All pregnant women with a family history of thyroid disease or symptoms of thyroid problems

Treatment

Replacement therapy with synthetic thyroid hormones is typically provided as a single daily tablet, usually prescribed by a pediatric endocrinologist. Thyroid hormones are essential for normal brain development in infants and children, so it’s crucial to administer the correct dose of synthetic hormone. Since the body may require higher doses over time, the child should be regularly retested to ensure they are receiving the right amount of hormone, with the dose adjusted as needed.

 Conclusion

Most children with hypothyroidism who follow their medication plan can experience normal growth and development. Since thyroid hormone replacement is based on weight and age, more frequent check-ups are required while your child is still growing.