Acquired Hypothyroidism in Children

What is acquired hypothyroidism?

Acquired hypothyroidism (hi-po-THI-roi-dizm) is a condition where the thyroid gland makes too little or no thyroid hormone. This occurs anytime during childhood and usually affects children starting at six months of age. The thyroid gland is a butterfly-shaped organ that can be found in the front part of your neck. Thyroid hormones are special chemicals that help control how your body works. This includes keeping a normal body temperature, heart rate, and growth. The thyroid hormones also control how your body uses energy, and affects weight gain and loss. In children, thyroid hormones play an important role in normal growth and development.

What causes acquired hypothyroidism?

The following conditions may cause or increase your child's risk of having acquired hypothyroidism:

Autoimmune disease:

The immune system is your body's defense against infections and diseases. A problem with the immune system may make the body attack even its own cells. Autoimmune thyroiditis (swelling of the thyroid gland) is the most common autoimmune disease that may cause acquired hypothyroidism.

Delayed onset of congenital hypothyroidism:

Some children who have hypothyroidism when they are born, may only show signs and symptoms much later in childhood.

Diet:

Having too little or no iodine in your child's diet may cause hypothyroidism. Iodine is an important mineral used by the thyroid gland to work correctly and make thyroid hormones.

Family history:

Having a family member with hypothyroidism or autoimmune disease may also increase your child's risk.

Medicines:

Taking certain medicines, such as those used to treat depression or other mental problems, may cause hypothyroidism. Medicines to treat hyperthyroidism (too much thyroid hormone) may also decrease the thyroid hormones in your child's body.

Treatments:

Radiation therapy used to treat cancers of the head and neck can destroy your child's thyroid gland. Surgery to remove all or part of the thyroid gland makes him more likely to develop hypothyroidism.

Other diseases or conditions:

Having thyroid problems, such as an enlarged or swollen thyroid. Nodules (lumps) caused by infections or cancer may grow in your child's thyroid and affect how it works.

What are the signs and symptoms of acquired hypothyroidism?

The signs and symptoms of acquired hypothyroidism may be different depending on your child's age.

Early signs and symptoms:

Bulging soft mass in the belly button.

Coarse or dull-looking facial features.

Delay or failure in growth and development.

Dry, flaky skin or thin and brittle fingernails or hair.

Hoarseness and large tongue.

Large arm and leg muscles.

Later signs and symptoms:

Feeling depressed, irritable, or lacking energy.

Feeling too cold when the temperature is just right or normal for everyone else.

Learning, speech, or behavior problems

Problems moving his bowel, such as constipation (dry, hard stools).

Delay in sexual development, like breasts or testes.

Swelling of his whole body, very slow heartbeat, and troubled breathing.

Teeth may erupt (appear) late.

How is acquired hypothyroidism diagnosed?

Your caregiver will ask you about your child's health. This may include information on what signs and symptoms he may have and when they started. You may also be asked about his past diseases, and medicines he has taken, or are taking now. You may also be asked about your family's health.

Blood tests:

These may be done to see how well the thyroid is working. These tests may tell his caregiver how low the levels of thyroid hormones are in his blood. These may also be used to see how well his thyroid is responding to the treatments.

Thyroid scan:

This test shows caregivers how your child's thyroid is working. Radioactive dye may be put into your child's IV line or given to him to drink. The working part of the thyroid gland absorbs (soaks up) the dye. Two to 48 hours later, caregivers put a machine called a gamma camera over his neck. The machine takes pictures showing the areas of his thyroid that absorbed the dye.

Thyroid ultrasound:

This is a test that looks at the inside of your child's thyroid gland. Sound waves are used to show pictures of his thyroid gland on a TV-like screen.

X-ray:

This is a test that takes pictures of the inside of your child's body. Your child's caregiver may use it to look for any problems and see how his lungs and heart are doing. X-ray pictures can also check your child's bones. These may help his caregivers see if he has problems with his growth and development.

How is acquired hypothyroidism treated?

Treatment for acquired hypothyroidism will depend on the cause, your child's health, age, and the level of his thyroid hormones. Thyroid hormone medicines are given to replace and raise the hormone levels back to normal. If another disease or condition has caused his acquired hypothyroidism, it will also be treated. Medicines may also be given to decrease the symptoms of acquired hypothyroidism.

What problems can acquired hypothyroidism cause?

Hypothyroidism if not diagnosed early or left untreated, may cause learning problems, poor growth and intelligence, or mental retardation. Your child may also develop myxedema which is a dangerous condition. This causes extra fluid and swelling in your child's legs, ankles, lungs, or around his heart. Your child's temperature may go very low, and his heart may beat very slowly. He may have seizures (convulsions), or go into a deep coma and die if he does not get medical care quickly.

Where can I find support and more information?

Having a child with hypothyroidism may be hard for you and your family. You and those close to your child may feel angry, sad, or frightened. These feelings are normal. Talk to your child's caregivers, family, or friends about your feelings. You may also want to join a support group. This is a group of people who also have hypothyroidism or other thyroid problems. Contact the following for more information:

American Academy of Family Physicians
PO Box 11210
Shawnee Mission, KS 66207-1210
913-906-6000
1-800-274-2237
http://www.aafp.org

American Thyroid Association
6066 Leesburg Pike, Suite 550
Falls Church, VA 22041
703-998-8890
800-849-7643
www.thyroid.org