Common Thyroid Disorders in Children

J Raine

Great Ormond Street Hospital for Sick Children, London

Endocrine Nurses Training Course 9-11 September 2004
Wills Hall, Stoke Bishop, Bristol, BS9 1AE

This talk will concentrate on thyroid disorders unique to children and on some common disorders stressing the difference between children and adults.

Thyroglossal cysts which are cystic remains of the fetal thyroglossal tract may occur. Treatment is surgical. Congenital hypothyroidism is a common disorder with an incidence of 1 in 4000. The most common cause is an absent or dysplastic gland. Other causes include an ectopic gland or dyshormonogenesis. A radio-isotope scan helps determine the exact diagnosis. Nationwide TSH screening of babies on day 7 of life has been a great medical success story preventing the learning difficulties which occurred in the past when this condition was not diagnosed till the child was several months or a year old. Treatment should be instituted urgently and in most cases is life long.

Sick preterm babies may have low thyroxine levels and 1 study suggested that thyroxine supplementation improved IQ. However, a Cochrane analysis of several studies has found insufficient proof to recommend routine thyroxine supplementation in preterm babies. Further research is in progress.

Neonatal thyrotoxicosis due to the transplacental transfer of maternal antibodies is extremely rare with an incidence of about 1 in 50000. These infants present with the signs of thyrotoxicosis and can be very sick. Treatment consists of carbimazole, propranolol and occasionally Lugol’s iodine and chloral hydrate. Fortunately the disease is self limiting and rarely lasts more than 3 months.

Autoimmune thyroiditis is quite common and can be very insidious. It is commoner in certain conditions such as Down’s syndrome in whom routine annual TFT’s should be performed from school age onwards. Children are characteristically short and overweight and in some cases it is clear in retrospect that the illness has been present for 2-3 years. Treatment is started gradually usually over 4-6 weeks. Although catch up growth and loss of weight do occur, if the history has been prolonged the child may never achieve their height potential. Most patients require treatment for life.

Graves disease is rare. Eye signs are usually milder than in adults. Patients are taller than expected for their mid-parental height centile and are thin in spite of a large appetite. It is usually treated initially with carbimazole and propranolol although a minority of paediatricians prefer a block and replace regime. Unfortunately, about 75% of patients relapse when treatment is stopped after 2 years. Options then include continuation of carbimazole, radioiodine or surgery. Most patients opt for further treatment or surgery. There have been concerns about the risks of cancer in children treated with radioiodine but there is no evidence of an increased risk and this treatment is now gaining popularity.

Thyroid neoplasms are very rare and usually present as a thyroid nodule in a euthyroid, autoantibody negative patient. The prognosis in the more common thyroid cancers is very good.

The opinions expressed in this paper are those of the speaker and do not necessarily reflect the views of the Society