What is the Thyroid Gland and what is its function?
The thyroid gland is an important endocrine organ in our body. It is a small, butterfly-shaped gland located in the front of the neck that produces the hormones thyroxin (T4) and triiodothyronine (T3).
These thyroid hormones have a major impact on the following functions:
- Growth, puberty and fertility
- Use of vitamins, proteins, carbohydrates, fats, electrolytes, and water
The secretion of these hormones is controlled by the thyroid stimulating hormone (TSH) produced by the pituitary gland. (The pituitary gland located at the base of the brain produces hormones which control other glands). For your child’s body to function properly, the thyroid gland needs to secrete the right amount of hormones into the blood stream.
What is Thyroid disease?
In general, the endocrine disorders in children are caused by too many or too few hormones. Similarly, the diseases of thyroid can be due to:
- Low thyroid hormone in blood (hypothyroidism)
- High thyroid hormones (hyperthyroidism)
- Thyroid swelling (goitre)
All the three diseases can occur in children, the most common being hypothyroidism.
Can you describe the signs and symptoms associated with thyroid problems?
A new born with hypothyroidism has jaundice, feeds poorly, shows lethargy and increased sleepiness, and constipation at birth. Later in childhood, this child displays poor memory, poor growth, mild weight gain, slowness in activities and increased sleepiness.
Hypothyroidism can also cause delay the onset of menses. Any child with poor academic performance, short stature, and delay in onset of menses or poor mental development should be evaluated with thyroid function tests which include free T4 and TSH.
Hyperthyroidism occurs due to increased production and release of thyroid hormones (also called Graves’ disease). Although Graves’ disease is uncommon in children, it leads to behavioural problems, emotional problems, declining school performance, and occasionally, loss of weight and anxiety.
Goitre is commonly seen in the adolescent age group around the time of puberty. Any localised swelling of the thyroid (nodule) should be imaged with thyroid ultrasound scan and if needed, a needle aspiration should be done to rule out cancer.
What causes thyroid problems in children?
Are babies affected?
Hypothyroidism (low thyroid hormones) can occur due to a primary problem in the thyroid or a secondary problem in the pituitary. (Tertiary Hypothyroidism, which is not very common, is because of the hypothalamus not stimulating the pituitary). Hypothyroidism is often referred to as an ‘underactive thyroid gland’. The most common cause is primary hypothyroidism. This can occur due to acquired or genetic reasons. The acquired causes are autoimmune (where the body produces antibodies that destroy own thyroid cells), iodine deficiency in diet, radiation and surgery.
Globally, one out of 4000 babies born is affected with hypothyroidism from birth. In India, the incidence is higher, and stands at one out of 2800. The reasons for this are the absence of thyroid gland or a defect in the enzymes involved in thyroid hormone production.
How prevalent are thyroid problems among Indian children?
Thyroid disorders are more common in girls. In India, the prevalence of goitre in school children varies from 8% to 21%. In another study of 6,283 school girls, 1,810 had goitre and 58 had autoimmune thyroid disease.
Can thyroid disease be prevented?
Congenital hypothyroidism, autoimmune hypothyroidism and Graves' disease cannot be prevented. If hypothyroidism is not diagnosed and treated, children can have mental retardation and growth failure. Hypothyroidism was a common occurrence on account of iodine deficiency four decades ago. Now, with universal salt iodisation (e.g. Tata salt), the problem is rarely seen.
All new born babies should undergo thyroid testing as part of a neonatal screening to identify congenital hypothyroidism. Although we cannot prevent thyroid abnormalities, early detection and treatment by a paediatric endocrinologist can help such babies have a normal brain development. Smoking increases the risk for thyroid disease, particularly autoimmune hypothyroidism. Healthy living is an important part of recovery from thyroid conditions.
Can you explain diagnosis and treatment options available for children with thyroid disease?
Hypothyroidism is diagnosed through a blood test to identify free T4 and TSH. A single daily tablet of Thyroxin taken orally in the early morning hours on an empty stomach helps manage the condition. Nothing should be consumed for 30 minutes after this except water. Your endocrinologist will periodically monitor the response with a blood test for TSH every 6 to 12 weeks. Taking too much of the thyroid hormone will speed up metabolism and can cause a rapid or irregular heart rate and loss of calcium from the bone. However, excess thyroid hormone levels are unlikely to occur when the treatment is carefully prescribed and monitored. Treatment of congenital hypothyroidism should begin soon after birth. In most cases, your child will need to take daily thyroid hormone tablet throughout life.
Graves’ disease is diagnosed by the findings of high free T3, high free T4 and low TSH, through blood tests. A thyroid scan using nuclear imaging can confirm the problem. Anti-thyroid drugs are used for treatment, and these bring down production to normal levels. Radioiodine therapy which is available in select centres across India (available in Apollo Hospital, Chennai) is used on children after they cross 10 years of age, and if there is no response to anti-thyroid drugs. Surgical removal of thyroid is another option. However this brings about the need to take Thyroxin supplements for life.
What you should know
- Make sure that your new born baby is screened for thyroid functions under the neonatal screening program.
- Always use iodised salt in your diet.
- Any child with poor academic performance, short stature, and delay in the onset of menses or poor mental development should be evaluated with thyroid function tests including free T4 and TSH. Consult a paediatric endocrinologist.
- Avoid smoking at home if your child is suffering from Graves' Disease.
- Ensure prescription drug compliance.
- Its a myth that food items like cauliflower, radish, soybean and cabbage aggravate thyroid conditions.
Dr S Ramkumar, a consultant diabetologist and endocrinologist at Apollo Hospitals, Chennai.