Hypothyroidism in Kids: Causes, Symptoms & Treatment

The thyroid gland is one of the most important glands in the human body, and plays a vital role in your overall development. Proper functioning of the thyroid is essential for the growth of a child, and a thyroid deficiency can lead to multiple disorders.

What Is Thyroid?

The thyroid is a butterfly shaped, ductless gland which is located in the neck. The gland secretes hormones such as the Thyroxine and Triiodothyronine, which are responsible for ensuring proper growth and development, maintaining normal heart rate to control body weight, and regulating the body temperature.

What Are The Types Of Thyroid Disorder?

At times, the thyroid gland might not function properly, resulting in an imbalance of hormone production, leading to a thyroid disorder. Thyroid disorders can be of two basic types:

1. Hypothyroidism –

This condition is caused by the dip in thyroid hormones in the blood. Hypothyroidism is known to affect women more than men and can get severe with age.

2. Hyperthyroidism –

This refers to an increase of thyroid hormone in the blood because of an overactive thyroid gland.

What Is Hypothyroidism?

As discussed, hypothyroidism is an endocrine disorder where the thyroid gland is underactive and does not produce enough hormones required for the proper functioning of the body.

Types of Hypothyroidism

The condition can, in turn, be divided into two types. These include:

1. Congenital Hypothyroidism

This is a thyroid disorder which occurs when the thyroid gland does not develop or function properly prior to birth. This is a common problem which can be diagnosed during the newborn screening process. The doctor will determine the course and length of treatment for this disorder based on factors like the child’s health and history of this disorder in the family.

2. Autoimmune Hypothyroidism: Chronic Lymphocytic Thyroiditis

This condition is caused by an autoimmune disorder known as chronic lymphocytic thyroiditis and occurs when the child’s thyroid gland is attacked by the immune system. This results in damage and decreased functioning of the thyroid gland.

3. Latrogenic Hypothyroidism

This occurs when the thyroid gland stops producing thyroid hormones in children after being medically destroyed or removed surgically.

4. Central Hypothyroidism

This is a condition where the brain does not make the thyroid stimulating hormone (the signal that tells the thyroid gland to work). The abnormal development of the hypothalamus or pituitary glands can cause central hypothyroidism.

Who should be screened for hypothyroidism?

Thyroid screening should be performed in the following cases:

• Children who fail the thyroid tests in the new-born screening
• Children who have poor linear growth
• Children with history of abnormal development or brain injury
• Children who have undergone cranial irradiation as a part of treatment for cancer
• Children with symptoms of hypothyroidism such as fatigue or weight gain
• Pregnant women who have had family history of thyroid disease

Causes Of Hypothyroidism In Kids

In children, the condition can be congenital or acquired after birth. It can also be caused due to autoimmune diseases, radiation therapies, removal of the thyroid gland, or due to the side effects of medication. Although such cases are rare, the disease can also be caused due to the treatment received for hyperthyroidism.

Sign and Symptoms Of childhood hypothyroidism

The symptoms are usually subtle and resemble symptoms of other medical conditions. The condition can go undetected for many years because of its non-specific nature.

Following are the symptoms of hypothyroidism:

• Fatigue
• Weight gain
• Slower reaction time
• Constipation
• Frequent instances of cold
• Dull facial expression
• Swollen and puffy face
• Droopy, tired eye-lids
• Sparse, dry and coarse hair
• Slow pulse and heart rate
• Frequent muscle cramping
• Poor growth

Since these symptoms can be associated with a large number of medical conditions, a doctor should be consulted to find out the real cause of these symptoms in children before opting for treatment for hypothyroidism.

Diagnosis and Tests

Here are some of the tests available to identify hypothyroidism in children:

• Thyroid functioning screening
• Anti-thyroid antibody level studies
• Nuclear medicine uptake and scan
• Thyroid ultrasound

Treatment

It is important to rectify this disorder in the child as it can hinder the growth and development of the child and have an adverse effect on the quality of life.

Hypothyroidism can be treated by hormone replacement therapy, where the deficient thyroid hormones are replenished by administering levothyroxine, a chemical which is identical to thyroxine.

The doctor might also prescribe medication to cure this condition in some cases.

When To Treat Hypothyroidism

Treatment in case of congenital hypothyroidism should be started immediately after the child is born and should be monitored closely. Most cases of congenital hypothyroidism will require lifelong hormone replacement.

In case of acquired hypothyroidism, the start of treatment and the necessary dosage of medicine are dependent on the age and weight of the child with this condition.

Course Of Medical Treatment

If a child is diagnosed with the condition, L-thyroxin is administered as a remedy. Here is a guideline of the recommended dosage. Do remember, however, that a doctor must be consulted before medicine is offered to the child.

1. For acquired hypothyroidism

The course of administering L-thyroxine for acquired hypothyroidism is as follows:

• For age group of 1 to 3 years: 4 to 6 mcg/kg once in a day
• For age group of 3 to 10 years: 3 to 5 mcg/kg once in a day
• For age group of 10 to 16 years: 2 to 4 mcg/kg once in a day
• For age group higher than 17 years: 1.6 mcg/kg once in a day

2. For congenital hypothyroidism

For treatment of congenital hypothyroidism, the dosage of L-thyroxine should be 10 to 15 mcg/kg, administered once in a day. The medication should start immediately and should be monitored closely.

Monitoring Of Hypothyroidism Disorder in a Child

Children who suffer from the disorder need to be monitored frequently during the first few years of their life. The monitoring frequency of the disorder is as follows:

• First 6 months after birth: Child to be monitored every one to two months
• Between 6 months to 3 years from birth: To be monitored every three to four months
• From 3 years to end of growth: To be monitored every six to twelve months

Hypothyroidism And Being Overweight

Thyroid hormones are closely related to body composition as they regulate basal metabolism, lipid metabolism, glucose metabolism, food intake and fat oxidation. Thyroid dysfunction can lead to changes in body weight and composition.

This disorder leads to decreased thermogenesis, decreased metabolic rate, higher body mass index and obesity. Even subclinical hypothyroidism can lead to significant changes to body weight, resulting in increased risk of obesity.

Challenges for parents

The effects of hypothyroidism in a child can be severe and last for a lifetime. This condition poses a severe challenge for the parents as they need to closely monitor the development of their child, and ensure timely and effective treatment of the disorder and its symptoms.

The treatment is a slow process which can even last for a lifetime. In such situations, it becomes extremely important for the parents to be patient and support their child throughout.

Hypothyroidism is a complex disorder which has a direct effect on the growth and development of a child. It is important to take necessary treatment immediately and continuously so that the child can have a chance to lead a normal life. Proper medication and monitoring can reduce the impact of this condition significantly.