Thyroid Disease in Children
By Robyn Koumourou, 2001
Although thyroid disease occurs less frequently in children than in adults, the signs and symptoms can be
similar. However, there are a few important differences that need to be brought to light.
Thyroid gland disorders have a profound effect upon the human body. The thyroid gland is located at the front of the neck, just below the Adam’s apple. It is responsible for the speed of all metabolic and chemical processes in our body, by affecting every cell, tissue, and organ. The thyroid gland is therefore essential for life, growth and development.
When the thyroid gland produces too much thyroid hormone (becoming overactive), the condition is called Hyperthyroidism. When the thyroid gland produces too little thyroid hormone (becoming underactive), the condition is called Hypothyroidism.
Congenital hypothyroidism is a disorder that affects infants at birth, and occurs in about 1 in 4000 live-born babies. It is characterized by the loss of thyroid function, due to the thyroid gland failing to develop normally. In some cases, the gland is totally absent. If there is a delayed diagnosis, and immediate treatment is not given, congenital hypothyroidism can lead to defects in growth and development, and severe mental retardation.
Fortunately, routine testing for thyroid function in newborns has been mandatory since 1976, both in Victoria and NSW. Within the first week of life, a heelprick blood sample is taken to assess an infant’s thyroid hormone level. If any abnormality is found, a repeat blood sample is taken. If this confirms congenital hypothyroidism, the infant is immediately given thyroid hormone replacement therapy. Normal growth and development would then continue, with no adverse affects on the child’s mental capacity.
Before newborn thyroid screening began, this condition was easily missed. Even within a few days, subtle symptoms would emerge, such as, poor feeding, constipation, low body temperature, cool skin, slow pulse, prolonged jaundice, and increased sleepiness, and decreased crying. After a few weeks, other physical signs would become more noticeable, such as, poor growth and development, dry skin and hair, poor muscle tone, slow tendon reflexes, hoarse crying, enlarged tongue, umbilical hernia, and puffiness or swelling. By this time, there would already be some devastating consequences. Treatment with thyroid hormone replacement would resolve most of the physical symptoms, but the child would more than likely have permanent brain damage.
Hyperthyroidism in Newborns
Hyperthyroidism, an overactive thyroid gland, is only seen occasionally in newborns. This condition is referred to as neonatal hyperthyroidism. This only occurs when fetal hyperthyroidism is not discovered earlier. If the mother has Graves’ disease, the thyroid-stimulating antibodies in her blood can cross the placenta and stimulate the unborn child’s thyroid gland, thus producing too much thyroid hormone. Some newborns may be hardly affected, if the levels of antibodies are low. No treatment may be necessary, as the mother’s antibodies will soon clear from the baby’s bloodstream, usually within two to three months. However, in rare circumstances, the levels of stimulating antibodies are enough to cause severe thyrotoxicosis. Treatment with antithyroid medication will be given immediately to correct the hormone imbalance. Newborns with advanced hyperthyroidism display similar symptoms to those in adults, such as, an extremely fast pulse, prominent eyes, irritability, flushed moist skin, increased appetite, little weight gain, and a body structure that is long and thin. Fortunately, treatment with antithyroid drugs will only be needed for a short period of time, until the stimulating antibodies pass from the baby’s bloodstream.
Hashimoto’s Thyroiditis in Children
The most common cause of hypothyroidism in children and adolescents is Hashimoto’s thyroiditis, an autoimmune disease. Here, the body’s own immune system attacks the thyroid gland and interferes with the production of thyroid hormones. The onset of this condition can occur at any age, and the diagnosis may be easily overlooked for years, as the symptoms of hypothyroidism develop very slowly. As the thyroid gland becomes increasingly underactive, physical and mental changes will become more obvious. Often the first sign is that the child’s growth rate decreases unexpectedly and skeletal development is delayed. The child may also have an obvious swelling of the neck (goiter), as the thyroid gland becomes inflamed. Other symptoms may emerge, such as, unusual tiredness or lethargy, dry itchy skin, increased sensitivity to cold, weight gain or generalized swelling, poor concentration, decreased energy, and constipation. If hypothyroidism is suspected, a simple blood test is taken, measuring the levels of thyroid hormone, and Thyroid Stimulating Hormone (TSH), in the blood. The presents of thyroid antibodies are also helpful in confirming the diagnosis.
The treatment for Hashimoto’s thyroiditis in children and adolescents is exactly the same as in adults. Thyroid hormone replacement (T4 - Thyroxine) is taken on a daily basis, and is taken for life. The dosage of thyroid hormone will need to be age-appropriate, as the body’s demands for thyroid hormone vary with age. Regular thyroid function tests will need to be assessed by a doctor to ensure that normal hormone levels remain stable.
For those children and adolescents being treated for hypothyroidism, the results are mainly positive. The majority of their symptoms will disappear, and the body’s time for ‘catch-up’ growth will begin. An increase in bone development will also occur. However, in children who have had long-standing hypothyroidism, ultimate height potential may be partly lost. As the child regains normal thyroid function behavioural problems may arise as their physical and mental processes speed up. An increase in energy and alertness may lead to a decreased attention span and a loss of concentration, especially in school. Teachers should be made aware of the child’s condition, as well as treatment and possible changes in behaviour. Over time, any problems with behaviour, or school difficulties, will resolve.
Graves’ Disease in Children
The most common cause of Hyperthyroidism in children and adolescents is an autoimmune condition called Graves’ Disease. In Graves’ disease the body produces antibodies that stimulate the thyroid gland uncontrollably, to make too much thyroid hormone. Children can have similar symptoms to adults, although they are less likely to complain about them. Initially the most prominent sign of this condition may be that the child displays increased energy. They may appear hyperactive and restless, be noisier in class, and easily distracted. This may lead to poor academic performance, and parent frustration. A child’s hyperthyroidism may not be diagnosed until more pronounced signs and symptoms appear. These include the development of eye complications (swelling) and an enlarged thyroid gland.
Other symptoms that may appear, look like the following: a fast pulse, nervousness, heat intolerance, weight loss, accelerated growth rate, prominent (or bright) eyes, shaky hands, muscle weakness, diarrhea, and sleep and behavioural disturbances. Once a thyroid disorder is suspected, a simple blood test is performed to measure the levels of thyroid hormones and Thyroid Stimulating Hormone (TSH) in the blood. The presents of thyroid antibodies may also be helpful in confirming the diagnosis. If test results come back positive, then appropriate treatment is commenced immediately.
Treatment of hyperthyroidism in children initially involves the use of antithyroid drugs, such as propythiouracil or cabimazole, and if well tolerated, these may be continued for months or even years. For some children, these drugs alone stabilize their condition, and no further treatment is needed. For others, surgery or even radioactive iodine may be necessary, depending on the severity of their thyroid disorder, or their response to antithyroid medication. Throughout a child’s treatment protocol, thyroid hormone levels will need to be regularly monitored, along with their clinical symptoms.
In children and adolescents with Graves’ Disease, the main difficulties usually occur before treatment is initiated. Once their condition is under control, their physical and mental capabilities will return to normal.
In children and adolescents receiving treatment for their thyroid disorder, parents involvement is vital. Parents will need to supervise the taking of medication on a daily basis, and carefully monitor their child’s progress. They will also need to be aware of the signs and symptoms of under-medicating, or over-medicating, so they can work with their doctor to obtain the right level of medication.
As children grow, it is important for parents to keep close track of their child’s thyroid hormone levels, as periodic changes in dosage will occur with changes in age. Doctors often recommend that a child have blood tests at least every six months, or even more frequently while they are young. Some children may have a tendency to neglect their medication regimen, and this may lead to symptoms reappearing.
Thyroid disorders can run in families, so it is important to let your doctor know of your family background. If close family members or parents have either hypothyroidism or hyperthyroidism, then it would be wise to keep a close eye on the children in the family. Girls tend to be especially prone to developing thyroid problems, due to hormonal changes throughout their life.
In summary, the signs and symptoms of thyroid disease are similar in children, adolescents, and adults. However, there are a few key differences that relate to growth, development and behaviour. If children are treated early and appropriately, with regular monitoring, they will grow and develop normally, and enjoy life as a child.
Mary Shomon, 'Helping Your Hypothyroid Child, Jan 12, 2019' - HealthCentral
© Robyn Koumourou.