Common thyroid conditions in children
- thyroid nodules
- thyroid cancer
Sometimes children are born with a thyroid problem. In other cases, surgery, disease, or treatment for another condition causes it.
Hypothyroidism in children
Children can get different types of hypothyroidism. Congenital hypothyroidism occurs when the thyroid gland doesn’t develop properly at birth. Hypothyroidism is the most common thyroid disorder in babies, children and teenagers. Routine testing at birth uncovers hypothyroidism in one in every 1,500-3,000 newborns. The cause is usually a problem with the development of the thyroid gland, located at the base of the neck.
Hypothyroidism can also develop later in childhood or the teen years. Risk is four times higher in girls than in boys. And young people with a family history of autoimmune diseases or who have Down syndrome, Turner syndrome, type 1 diabetes or coeliac disease are also at a much higher risk.
Autoimmune hypothyroidism is caused by an autoimmune disease in which the immune system attacks the thyroid gland. This type is often caused by chronic lymphocytic thyroiditis. Autoimmune hypothyroidism often appears during the teenage years, and it’s more common in girls than boys.
Iatrogenic hypothyroidism happens in children who have their thyroid gland removed or destroyed — through surgery, for example.
Symptoms of hypothyroidism in children include:
- weight gain
- intolerance to cold
- dry, thin hair
- dry skin
- a slow heartbeat
- hoarse voice
- puffy face
- increased menstrual flow in young women
Parents and doctors may not suspect a sluggish thyroid at first as these symptoms are common complaints of everyday life, not specific to thyroid disease. A slow-down in growth, a delay in developing at puberty and, for girls, irregular menstrual periods are also key symptoms.
Hyperthyroidism in children
There are multiple causes of hyperthyroidism in children. Graves’ disease is less common in children than in adults. Graves’ disease often appears during the teenage years, and it affects more girls than boys. Hyperthyroidism accounts for 15% of paediatric thyroid disorders, with most cases attributable to autoimmune hyperthyroidism (Graves’ disease). In the UK, the incidence of Graves’ disease among paediatric patients is 1 case per 100,000. Graves’ disease is more common among girls, with a peak incidence between 10 and 15 years of age.
Hyperfunctioning thyroid nodules are growths on a child’s thyroid gland that produce too much thyroid hormone. Some hyperthyroid symptoms may also go unnoticed as being part of being a “typical teenager” these include restlessness, trouble sleeping, hyperactivity, mood swings and poor concentration. Your teenager may also experience increased bowel movements which they may be too embarrassed to mention to you.
Thyroiditis is caused by inflammation in the thyroid gland that makes thyroid hormone leak out into the bloodstream.
Symptoms of hyperthyroidism in children include:
- fast heart rate
- bulging eyes (in children with Graves’ disease)
- restlessness and irritability
- poor sleep
- increased appetite
- weight loss
- increased bowel movements
- intolerance to heat
Treatments for Hyperthyroidism in children and teenagers
Like adults, adolescents with Graves’ disease can be effectively treated with anti-thyroid drugs, radioiodine and thyroidectomy. Among these three treatments, there are some differences in the time needed to reduce raised thyroid hormone levels to normal.
In contrast to adults, most children with Graves’ disease need treatment with an anti-thyroid drug for a long time. However, the chances of a long-term cure of hyperthyroidism following a prolonged course of anti-thyroid drug therapy are lower than in adults and relapse is common.
Radioiodine therapy is a very effective treatment and in more than 1,000 children treated in this way there is no evidence of an increase in thyroid tumours or other non-thyroid problems. Because there is a theoretical risk of increased sensitivity of the thyroid gland in young children, however, most paediatric endocrinologists prefer not to treat them until they are ten years or older if possible. It is increasingly being used as the first line of treatment in teenagers.
Thyroid nodules in children
A thyroid nodule is an abnormal growth of thyroid cells that forms a lump within the thyroid gland. There may be one or more nodules in the thyroid gland and each one should be evaluated. Most thyroid nodules are benign (not cancerous); however, a small proportion may contain thyroid cancer. In order to diagnose and treat thyroid cancer at the earliest stage, thyroid nodules need evaluation.
Thyroid nodules come to medical attention in a variety of ways. Most thyroid nodules do not cause symptoms and the thyroid gland usually works normally despite the nodule. Some nodules are found by the patient, a friend, or a parent noticing a lump in the neck during routine daily activities. Some are discovered during routine physical examinations by dentists, and some are found by radiologic imaging (ultrasound, CT scan, or MRI), usually being performed for unrelated reasons. Rarely, nodules can get so large that they cause difficulty breathing or swallowing because the nodule is pressing on the windpipe or oesophagus.
Thyroid nodules that are benign usually do not need to be removed, but the patient should have a follow-up ultrasound to make sure the nodule has not grown or changed 6 to 12 months later. In children and adolescents, doctors usually recommend surgical removal of nodules if they are very large (measuring more than 3 to 4 cm across), if they are producing too much thyroid hormone (“hot nodules”), or if the nodule is impacting quality of life, even if they seem benign following a biopsy. In about 25% of patients, the results from a biopsy are not clear on whether a nodule is benign or malignant. When this occurs, the patient, family, and doctor will discuss the advantages and disadvantages of surgery versus close follow-up with repeat ultrasounds.
Thyroid cancer in children
Thyroid cancer is the most common type of endocrine cancer in children, yet it’s still very rare. It’s diagnosed in less than 1 out of every 1 million children under age 10 each year. The incidence is slightly higher in teens, with a rate of about 15 cases per million in 15 to 19-year-olds.
Children with any thyroid nodules found to contain thyroid cancer, or that are suspected to be cancerous, should have surgery by an experienced thyroid surgeon to remove the nodule and/or all the thyroid gland. More than 90% of thyroid cancers in children are papillary thyroid cancer. Even if this cancer is advanced when it is discovered, the vast majority of children do very well and live long, healthy lives after a thyroid cancer diagnosis.
As in adults, a thyroid nodule (localised lump or mass) is a common symptom of thyroid cancer. Thyroid nodules that develop in children and adolescents are even more likely to be cancerous than thyroid masses in adults. In adults with thyroid nodules, only about 5% turn out to be cancer. In children and teenagers, that percentage increases to over 26%. All children or teens who develop a lump in the thyroid or neck should be evaluated by a physician in order to ensure early diagnosis and treatment if cancer is indeed present. The prognosis is usually very good for children who have cancer that has not spread outside of the thyroid gland.
Symptoms of thyroid cancer in children include:
- a lump in the neck
- swollen glands
- tight feeling in the neck
- trouble breathing or swallowing
- hoarse voice
As with adults, surgery is the mainstay of treatment for thyroid cancer in children. Fortunately, the prognosis is usually very good for children with thyroid cancer. And depending upon the type of cancer and extent of spread, radioactive iodine treatments, chemotherapy, or radiation therapy may be given after surgery. Replacement thyroid hormone in pill form may be required for life after treatment.
Preventing thyroid dysfunction
In most cases, you can’t prevent hypothyroidism or hyperthyroidism. In developing countries, hypothyroidism is often caused by iodine deficiency.
Hyperthyroidism is often caused by Graves’ disease, an autoimmune disease that isn’t preventable. You can set off an overactive thyroid by taking too much thyroid hormone. If you’re prescribed thyroid hormone, make sure to take the correct dose. In rare cases, your thyroid can become overactive if you eat too many foods that contain iodine, such as table salt, fish, and seaweed.
Though you may not be able to prevent thyroid disease, you can prevent its complications by getting diagnosed right away and following the treatment your doctor prescribes.