Training in Paediatric Endocrinology – as part of my Endocrinology specialty rotation at Birmingham Children’s Hospital, Birmingham, U.K.
Α) Thyroid diseases
Among children, the age of onset of hypothyroidism (in the child, this is defined as an underactive thyroid gland or else non-production of hormones by the gland) has been dropping in recent years, with the result that many children are needing to initiate treatment from early on. Age criteria to determine among those children who have no aggravating factors which should be screened do not at present exist, thus the decision must be taken based on a combination of data assembled by an endocrinologist who is specialized in paediatric endocrinology. Frequently, thyroxine doses are lower than the adult ones and the decision whether to start treatment or not will be more cautious.
Treatment for hyperthyroidism, which is rarer, is primarily carried out with drugs. Radioactive iodine is considered as safe in children over the age of 10 and the risk of tumorigenesis is low.
Thyroid nodules in childhood and adolescence are more likely to be malignant than they are in adults; thus, investigation into them must be immediate and monitoring of them extremely thorough and systematic.
In general, when thyroid diseases are not treated at these ages, they are likely to negatively affect the child’s growth as well as his/her academic performance at school.
Β) Diabetes mellitus type I and type II
The initial check-up for the presence of insulin-dependent type I diabetes mellitus and the decision on its treatment must be carried out in the Department of Diabetology of a children’s hospital, but further monitoring of insulin treatment may be conducted on an outpatient basis via the cooperation of an endocrinologist, a dietician and a psychologist.
Whereas in the past incidence of diabetes mellitus type II (whose treatment is with antidiabetic tablets) among children and adolescents was very rare, today it is ever more frequently appearing among these younger ages. Childhood- and adolescent-onset diabetes mellitus type II is making its appearance more and more often because of the coexistence of a sedentary lifestyle, unhealthy eating and obesity.
Children with diabetes mellitus who are on insulin treatment need to be investigated for possible presence of hypoglycaemia in order to determine whether there is coexistence of other endocrine diseases: the hypoglycaemia can then be reduced or prevented via modification of lifestyle and diet and through education. Adolescents are more susceptible than adults to develop hypoglycaemia, which is known to arise after starvation. Prolonged hypoglycaemia may also lead to neurodevelopmental disorders.
The rising prevalence of obesity among children and adolescents is primarily the result of chronic caloric imbalance, i.e. that too few calories are being expended for the amount of calories consumed, which means too much eating and too little physical activity. However, it ultimately stems from a combination of numerous causes including, as mentioned, an unhealthy diet and a sedentary lifestyle, but also various genetic, behavioural and environmental factors, all of which lead to increased fat deposition. Diagnosis in each child is carried out via monitoring of centile curves for weight and BMI in accordance with the child’s age. The decision about the child’s diet must be taken extremely carefully, ‘crash diets’ and very-low-calorie diets having been shown to very negatively impact the child’s development. Most importantly, each child must be taught from an early age to follow the rules of healthy eating and regular exercise since later on it is extremely difficult to change ingrained habits.
D) “Short” stature
This can be due to:
a) familial short stature
b) rare syndromes that affect growth (e.g. Down’s syndrome)
c) endocrinological-hormonal aetiologies
d) other disorders such as chronic gastrointestinal, cardiac, psychological, haematological, neurological diseases
e) unexplained causes when all other causes have been ruled out.
Diagnosis concerning short stature is carried out by the endocrinologist.
When necessary, growth curves for height are used to check the growth rate and height at regular intervals. In addition, special endocrine tests can be conducted that will be recommended by the specialized endocrinologist; it is to be noted that the simple measurement of fasting hormone levels does not suffice for an accurate diagnosis.
The decision as to administration of growth hormone or not and the monitoring of such treatment if decided upon needs to be made promptly. Monitoring is conducted based on the child’s growth and appropriate hormonal tests.
Ε) “Tall” stature
This is most often a cause for parent’s alarm when it concerns girls, though it may also relate to very tall stature in boys. Monitoring is required of the child’s growth based on age curves relevant for his age group in combination with that of the child’s development of gender characteristics. Use is made of the child’s medical history as well as that of the parents; if judged necessary, the appropriate endocrine tests are carried out. Once again it is stressed that the simple measurement of fasting hormone levels is not sufficient for a correct diagnosis. The causes of “tall” stature, as mentioned, may be hormonal, the result of rare syndromes, familial tall stature, early puberty, obesity, etc.
The aim of treatment is to delay bone growth and thus to achieve a reduction of final height. The treatment, tailored to the needs of each patient, consists of administration either of steroids (hormones) or of injectable medications that suppress the growth. In any case, the earlier the initiation of treatment, the better will be the final results.
F) Precocious puberty
This occurs more commonly in girls, fairly rarely in boys. Breast and testicular development are tracked as well as that of pubic and axillary (underarm) hair, height and weight, while the child’s and the family medical history are studied.
- Precocious puberty (puberty starts when the hypothalamus releases a hormone, the gonadotropin-releasing hormone, which signals to the pituitary gland to release two more hormones, which latter event marks the commencement of puberty) is that which starts at the age of 7-8 years in girls (breast development at 7 years and appearance of pubic and axillary (underarm) hair before the age of 8) and at the age of 9 in boys (development of the testes and penis and pubic and axillary hair growth).
- Idiopathic – no cause found
- Other causes may stem from disorders of the central nervous system (hypothalamus and pituitary) or may arise from tumours or growths in the ovaries, adrenal glands, pituitary gland or brain.
- Rare genetic syndromes
- Various endocrine disorders
Depending on the cause, there are various physical manifestations.
- precocious development of breasts (before the age of 6-7 years) and of andrenarchy (pubic and axillary (armpit) hair before the age of 7-8 years), and start of menstruation and ovulation.
- enlarged penis and testicles, pubic, axillary (armpit) and facial hair, production of sperm, acne, deepening of voice.
Hormone therapies are undertaken, tailored to the individual case, in order to delay development of puberty so as to prevent precocious epiphyseal fusion which would result in short stature.
G) Delayed puberty
This is the absence of the secondary sex characteristics at the age of 13 in girls and 14 in boys.
Delayed menarche (start of the girl’s period) means when it has not appeared by the age of 15 years.