Thyroid Diseases in Childhood:

A Guide to Symptoms, Diagnosis, and Treatment

Although they are much more common in older adults, thyroid disorders such as hypothyroidism and hyperthyroidism are not unheard of among infants, children, and adolescents. In fact, in the United States alone, it is estimated that as many as 1 in every 4000 infants born has a congenital thyroid disorder. Among Hispanic and Native American infants, the risk is even greater.

Other acquired thyroid diseases can develop later in childhood or adolescence. One of the age groups that has been most significantly impacted by the still-unexplained epidemic of thyroid cancer is adolescents age 15 to 19. Although infants, children, adolescents, and young adults account for less than 1% of all cases of thyroid disorders and diseases, they bear a disproportionate risk for developing certain types of disorders.

Because proper thyroid function is essential for normal growth and development in infancy and childhood, it is essential that any suspected thyroid disorder is monitored very carefully in young patients. This week, we will take a look at some of the challenges of preventing, diagnosing, and treating thyroid diseases and disorders that occur during childhood.

Childhood Hypothyroidism

Most cases of hypothyroidism in infants and children are congenital or acquired, that is, present from birth and inherited genetically. However, although most instances of the disorder in children are genetic in origin, they often are not properly diagnosed until later in childhood. If left untreated, congenital hypothyroidism can result in mental retardation, severe developmental delays, and even death.

The potential seriousness of congenital hypothyroidism has prompted lawmakers across the United States to require mandatory testing for the disorder. Today, most newborns are now given a routine test that screens basic thyroid function and detects the most serious forms of congenital hypothyroidism.

When a deficit in normal thyroid hormone levels are detected, the newborn begins treatment for thyroid disorder immediately. The typical treatment regimen includes a course of levothyroxine sodium that, in many cases, must be continued and monitored for life. If the drug is taken consistently and thyroid hormone levels remain stable, infants with congenital hypothyroidism suffer little or no ill effects from the disorder.

While these regulatory changes have initiated great strides in the early detection and treatment of congenital hypothyroidism in infants and children, this diagnostic test only applies to a few specific types of thyroid disorders. In some cases, an underactive thyroid gland is not detected until later in childhood. This is more likely to occur in milder cases that do not cause readily detectable symptoms.

Some common signs of hypothyroidism in infants include:

• Feeding, digestion, and appetite problems
• A bump, nodule, or general inflammation in the front part of the neck
• Jaundice (yellowing of the skin and eyes)
• Change in skin texture
• "Puffy" appearance
• Larger than normal "soft spots" on skull
• Respiratory disorders
• Enlarged tongue
• Slowed heartbeat
• Infrequent stools
• Lethargy
• Slow or no weight gain

If you have noticed any of these signs and symptoms in your infant, it's important to discuss your concerns with a licensed health care professional.

Childhood Hyperthyroidism

Although hypothyroidism is more commonly diagnosed in infants and children, hyperthyroidism is also sometimes seen in very young patients. Because of the relative rareness of this disorder, there are no standard screening procedures that are designed to detect an overactive thyroid gland in newborns.

However, in families with a history of hyperthyroidism, congenital hyperthyroidism can be diagnosed in newborns, infants, and young children. Like hypothyroidism, this disorder poses a grave threat to the infant's normal development if left untreated.

If repeated listens to the fetal heartbeat reveal an abnormally fast heart rate, further tests may be conducted to determine that the fetus' developing endocrine system is growing at a normal rate. In some cases, hyperthyroidism can be detected before birth. Ultrasound images can be used to check for abnormal goiter-like growths around the thyroid gland, as well. Likewise, the mother's thyroid health and hormone levels will also be investigated as a potential cause of the problem.

Signs and symptoms associated with hyperthyroidism in infants include:

• Lumps, growths, or inflammation in the thyroid region
• Larger than normal appetite and/or food intake
• Failure to gain weight
• Prominent, bulging eyes
• Rapid heartbeat
• High blood pressure
• Irritability and nervousness
• Frequent fevers
• High body temperature
• Rapid breathing
• Yellowing of the eyes and skin

If you are worried that your infant or young child may be experiencing thyroid problems, don't hesitate to discuss your concerns with a doctor. All thyroid disorders require immediate medical care, but the urgency is even greater when it comes to diagnosing and treating childhood thyroid disorders. By taking action as soon as you notice any problems, you could be greatly increasing your child's long-term health outlook.

Be sure to check back each week for more of the latest thyroid health news.

For Further Reading

• http://www.thyroid.ca/Guides/HG09.html

• http://www.tsh.org/disorders/pregnancy/newborns.html

• http://www.ehealthmd.com/library/hypothyroidismchildren/HYC_whatis.html