Flashcards in Endocrinology || Deck (94):
What type of diabetes do most children have?
Type 1 requiring insulin
What are the causes of type 2 diabetes in children (3)?
1. Obesity and increasing insulin resistance
2 Higher incidence in certain ethnic groups e.g. Asian/black children
3. Positive family history
What is the presentation of type 1 diabetes?
1. Common (3)
2. Less common (3)
How is it different to adults?
Unlike adults, children only present with a few weeks of symptoms
3. Weight loss
1. Secondary enuresis
2. Skin sepsis
3. Candida and other infections
Why is it important to diagnose type 1 diabetes early?
To avoid diabetic ketoacidosis
How is type 1 diabetes diagnosed in a child (3)?
Confirmed in a symptomatic child by finding a markedly raised random blood glucose (>11.1 mmol/L), glycosuria and ketosis
If in doubt:
1. Fasting blood glucose >7mmol/L
2. A raised HbA1c
What is the late presentation of T1DM or diabetic ketoacidosis (8)?
1. Smell of acetone on breath
4. Abdominal pain
5. Hyperventilation due to acidosis (Kussmaul breathing)
6. Hypovolaemic shock
8. Coma and death
What are the essential early investigations of diabetic ketoacidosis (7)?
1. Blood glucose(>11.1 mmol/L)
2. Blood ketones (>3.0 mmol/L)
3. Urea and electrolytes, creatinine (dehydration)
4. Blood gas analysis (severe metabolic acidosis)
5. Evidence of a precipitating cause e.g. infection (blood and urine cultures performed)
6. Cardiac monitor for T-wave changes of hypokalaemia
7. Weight (compare with recent clinic weight to ascertain level of dehydration)
What is the immediate management of diabetic ketoacidosis if they are hyperglycaemic, ketoacidotic, clinically dehydrated and/or vomiting, drowsy or clinically acidotic (5)?
1. Urgent hospital admission
-if in shock, initial resus with 0.9% saline.
-then dehydration should be corrected gradually over 48 hours (too rapid rehydration can lead to cerebral oedema)
-Monitor fluid in/output, blood glucose hourly, blood ketones (1-2 hourly), electrolytes, creatinine and acid-base status 2-4 hourly, and neurological state
3. Insulin infusion started after iv fluids running for 1 hour
-Monitor blood glucose hourly (aim for gradual reduction)
4. Potassium replacement started as soon as maintenance fluids are started (displacement from cells in exchange for H+ ions)
-Cardiac monitoring and 2-4 hour plasma potassium measurement until it is stable
5. Abx if diabetic ketoacidosis was precipitated by an intercurrent infection
What is the medical management of type 1 diabetes (4)?
-most children are started on a continuous subcutaneous insulin pump
-a multiple daily injection regimen (basal-bolus) with rapid-acting insulin given before each meal plus long-acting insulin in late evening and/or before breakfast to provide background basal insulin
2. Blood glucose monitoring
-Record should be kept in a diary or transferred from the memory of the blood glucose meter
3. Blood ketone testing mandatory during illness or when control is poor
4. Measurement of HbA1c should be checked 4x a year
What are the insulin injection sites (4)?
Why is rotation of the injection sites necessary?
Anterior and lateral aspects of the thigh, buttocks and abdomen
Needs to be rotated to prevent lipohypertrophy or more rarely, lipoatrophy
What blood glucose levels do people aim for with treatment of T1DM?
What does the HbA1c indicate?
The overall diabetes control over the previous 6-12 weeks
What is the initial non-medical management of T1DM (2)?
1. Intensive educational programme needed for parents and child
-Basic understanding of the pathophysiology of diabetes
-Injection of insulin: technique and sites
-Blood glucose (finger prick) monitoring
-Encouragement to exercise regularly
-Recognition and treatment of hypoglycaemia
-Psychological impact of a lifelong condition
-Where to get help/advice 24 hours a day
-Encouraged to eat a healthy diet and insulin doses to match carbohydrate intake
-High in fibre for sustained release of glucose
What are the aims of long term management of T1DM (7)?
1. Normal growth and development
2. Maintaining as normal a home and school life as possible
3. Good diabetes control through knowledge and good technique
4. Encouraging children to become self-reliant but with adult supervision until they are able to take responsibility
5. Anticipating and minimising hypoglycaemia
6. To maintain a HbA1c of less than 48mmol/mol (6.5%)
7. Helping adolescents to deal with the biological, psychological and social factors with their diabetes.
What are the long-term complications of diabetes (2)?
1. Macrovascular - hypertension, coronary heart disease, cerebrovascular disease
2. Microvascular - retinopathy, nephropathy, neuropathy
What are the problems that can interfere with diabetes control (7)?
1. Unhealthy diet
2. Infrequent blood glucose testing
3. Illness - viral illness common in the young
4. Exercise - vigorous or prolonged planned exercise requires reduction in insulin dose and increase in carbohydrate intake
5. Eating disorders
6. Family disruption
7. Inadequate family support
Who needs to be involved with the management of a child's diabetes (3)?
2. Diabetes team
How does the school help to manage the diabetes of a child (3)?
1. Managing dietary needs
2. Knowing what to do if child becomes hypoglycaemic
3. For younger children, help is needed to test blood glucose. calculate and give the prelunch insulin injection or bolus from the pump
What are the short-term complications of T1DM (2)?
2. Diabetic ketoacidosis
What are the causes of hypoglycaemia in children?
1. In neonatal period (1)
2. Beyond the neonatal period
1. Transient neonatal hypoglycaemia in neonates is common due to exposure to high levels of insulin in utero in mothers with diabetes or glucose intolerance
Beyond the neonatal period:
1. Insulin excess
-Excess exogenous insulin
-Autoimmune (insulin receptor antibodies)
2. Without hyperinsulinaemia
-Ketotic hypoglycaemia of childhood
-Inborn errors of metabolism
2. Leucine sensitivity
3. Fructose intolerance
4. Maternal diabetes
5. Hormonal deficiency
6. Aspirin/alcohol poisoning
What is the definition of hypoglycaemia?
Plasma glucose <2.6 mmol/L
but most will experience symptoms by below 4mmol/L
What are the clinical features of hypoglycaemia (4)?
What are the dangers of hypoglycaemia (2)?
3. CNS signs of irritability, headache, seizures and coma
4. May complain of hunger, tummy ache, sweatiness, feeling faint or dizzy
Can lead to seizures and coma
What are the investigations done for hypoglycaemia?
1. Blood (3)
2. Urine (2)
1. Glucose-sensitive strips with a meter
2. Confirm hypoglycaemia with lab blood glucose
3. Growth hormone, IGF-1, Cortisol, Insulin, C-peptide, Fatty acids, Ketones, Glycerol, Branched-chain amino acids, acylcarnitine profile, lactate, pyruvate
First urine after hypoglycaemia
1. Organic acids
2. Consider saving blood and urine for toxicology, e.g. salicylate, sulphonylurea
What is the treatment of hypoglycaemia?
In hospital (1)
Not in hospital (2)
1. In hospital: iv infusion of glucose (max of 5ml/kg of 10% glucose bolus followed by 10% glucose infusion)
If not in hospital:
2. Orally if early stages - easily absorbed glucose in tablets or sugary drink or oral glucose gels can be absorbed from the buccal mucosa.
3. In severe cases with reduced consciousness, glucagon im injection and then carers should give the child some food (usually a biscuit or sandwich) to prevent the blood glucose dropping again.
Why are infants more prone to hypoglycaemia?
What needs to be avoided in infants to prevent hypoglycaemia?
Infants have high energy requirements and relatively poor reserves of glucose from gluconeogenesis and glycogenesis.
They are at risk of hypoglycaemia with fasting, so should never be starved for more than 4 hours e.g. preoperatively
What is the definition of short stature in children?
Height below the 2nd centile (i.e. 2 SD below the mean)
What is a sensitive indicator of growth failure?
Measuring height velocity
How do you measure height velocity?
2 accurate measurements at least 6 months, but preferably a year apart allow calculation of height velocity in cm/year
This is plotted at the midpoint in time on a height velocity chart
What must the height centile of a child be compared with (2)?
1. Weight centile
2. Estimate of his/her genetic expected height calculated from the height of his/her parents
What are normal or non-pathological causes of short stature (4)?
2. Constitutional delay in growth and puberty
3. Small for gestational age and extreme prematurity
4. Inadequate nutrition (rare)
What are pathological causes of short stature?
Long-term illness (5)
Chromosomal disorder/syndromes (4)
1. Coeliac disease
2. Crohn's disease
3. Chronic kidney disease
5. Congenital heart disease
2. Psychosocial deprivation
1. Hypothyroidism (usually autoimmune thyroiditis)
2. Growth hormone deficiency - rare (may be isolated e.g. Laron syndrome or secondary to wider pituitary dysfunction)
3. Cushing syndrome (usually iatrogenic)
1. Down syndrome
2. Turner syndrome
3. Noonan syndrome
4. Russell-Silver syndrome
What can be the causes of pituitary dysfunction in children leading to growth hormone deficiency (4)?
1. Congenital midfacial or midline defects
3. Hypothalamic tumour
4. Trauma e.g. head injury, meningitis and cranial irradiation
What are the symptoms of a craniopharyngioma (3)?
1. Abnormal visual fields (usually bitemporal hemaniopia)
2. Optic atrophy
3. Papilloedema on fundoscopy
What is Laron syndrome?
How are GH levels affected?
Condition due to defective GH receptors resulting in GH insensitivity
Patients have high GH levels but low levels of the downstream active product of GH known as IGF-1 produced at the growth plate and liver
What are the causes of Cushing's in children?
How common is it (2)?
Rare in children
1. Usually iatrogenic and induced by corticosteroid therapy
2. Non-iatrogenic Cushing syndrome is very unusual and may be caused by pituitary or adrenal pathology
What are the pathological causes of extreme short stature (2)?
1. Idiopathic short stature - no diagnostic explanation
2. Abnormalities in gene short stature homeobox (SHOX) located on the X chromosome
-Absence of one SHOX gene in Turner syndrome causes short stature
What are features of Russell-Silver syndrome (5)?
IUGR combined with some of the following:
1. Dismorphic features - Triangular shaped face with a small jaw and a pointed chin that tends to lessen slightly with age. The mouth tends to curve down
3. Excessive sweating as a baby
4. Continued poor growth with no "catch up" into the normal centile lines on growth chart
5. A striking lack of subcutaneous fat
What are the features of Turner's syndrome (6)?
1. Short and webbed neck
2. Low-set ears
3. Low hairline at the back of the neck
4. Short stature
5. Swollen hands and feet are seen at birth
What are the features of puberty in females (4)?
1. Breast development
2. Pubic hair growth and rapid height growth - occur almost immediately after breast development
4. Acne, axillary hair, body odour and mood changes
What are the features of puberty in males (4)?
1. Testicular enlargement to over 4ml volume, measured using an orchidometer - first clinical sign of puberty
2. Pubic hair growth
3. Rapid height growth
4. Acne, axillary hair, body odour and mood changes
What are the possible abnormalities of puberty (4)?
Premature sexual development:
1. Precocious puberty
3. Pubarche or adrenarche
4. Isolated premature menarche
What age is the development of secondary sexual characteristics considered premature?
1. 8yo in females
2. 9yo in males
How is precocious puberty categorised (2)?
1. Gonadotrophin dependent (central/true precocious puberty) from premature activation of the hypothalamic-pituitary-gonadal axis
2. Gonadotrophin independent (pseudo/false precocious puberty) from excess sex steroids outside the pituitary gland
How common is gonadotrophin-dependent precocious puberty in females and why?
Fairly common as ovaries are very sensitive to secretion of gonadotrophins from the pituitary gland
What is usually the cause of gonadotrophin-dependent precocious puberty in females?
Idiopathic or familial
How common are pathological causes of precocious puberty in girls? What are they caused by? How do they present?
Can be secondary to:
Gonadotrophin-independent causes such as excess androgens from congenital adrenal hyperplasia or adrenal tumours
1. present with pubic and axillary hair
2. adult body odour
3. virilisation of the genitalia before breast development
Gonadotrophin-dependent causes such as pituitary adenoma where pubertal development will be consonant but perhaps rapid
How can precocious puberty be investigated in females?
US examination of the ovaries and uterus
-The uterus changes from an infantile 'tubular' shape to a 'pear' shape with the progression of puberty and the endometrial lining can be identified close to menarche
How common is gonadotrophin-dependent precocious puberty in males and why?
Uncommon as the testes are relatively insensitive to secretion of gonadotrophins from the pituitary gland
What are the pathological causes of precocious puberty in males? What would be found on examination of the testes?
1. Bilateral enlargement of testes, volumes greater than 4ml - suggests gonadotrophin-dependent PP. Can be caused by:
-Secretion of beta-human chorionic gonadotropin from a liver tumour (rare)
2. Prepubertal testes suggest a gonadotrophin-independent cause e.g. adrenal pathology such as a tumour or congenital adrenal hyperplasia
3. Unilateral enlarged testis suggests a gonadal tumour
How are tumours in the hypothalamic region best investigated?
Cranial MRI scan
What is thelarche?
What age does it usually affect?
Premature breast development
Affects females between 6 months and 2 years of age
How does thelarche usually present (2)?
How is it differentiated from gonadotrophin-dependent precocious puberty?
1. Breast enlargement may be asymmetrical and fluctuate in size
2. Rarely progressing beyond stage 3 of puberty
Differentiated from PPP by absence of axillary and pubic hair and of a significant growth spurt
What is the course of thelarche?
Non-progressive and self-limiting
What is premature pubarche (adrenarche)?
When pubic hair develops before 8 years in females and before 9 years in males but with no other signs of sexual development`
What is the most common cause of premature pubarche?
Accentuation of the normal maturation of androgen production by the adrenal gland between the age 6-8 years
What is the course of premature pubarche?
What investigations would you do for premature pubarche to distinguish it from a non-classical congenital adrenal hyperplasia or an adrenal tumour (3)?
1. Urinary steroid profile
2. Evaluating levels of androgens in the blood
3. Measuring bone age
What is the definition of delayed puberty?
The absence of pubertal development by 14 years of age in females and 15 years in males
Is delayed puberty more common in boys or girls and why?
What are the most common causes?
Boys - relative insensitivity of the testes to gonadotrophin secretion
Most commonly due to constitutional delay in growth and puberty, may be induced by dieting or excessive physical training.
What are the basic investigations for delayed puberty in boys (2)?
1. Pubertal staging, especially testicular volume
2. Identification of long-term systemic disorders
Why is delayed puberty less common in girls?
Ovaries are sensitive to gonadotrophins
What investigations would be done for delayed puberty in girls (5)?
1. Karyotyping to identify Turner syndrome
2. Measure thyroid hormones
3. Measure sex hormones
4. Consider possibility of eating disorder
5. Consider pituitary pathology
What is the definition of overweight and obese for clinical use, in children?
Overweight = BMI over 91st centile
Obese = BMI over the 98th centile
What are the risk factors for obesity in children (4)?
Due to changes in the environment and behaviour relating to diet and activity
1. More energy-dense foods
2. Decreased energy expenditure due to increased transport in cars
3. More time in front of screens instead of playing outside
4. Low socioeconomic homes are a risk factor
Where are obese children managed?
If the child has complications or if an endogenous cause is suspected, then specialist paediatric assessment is indicated
What is the principle of management of obese children?
The aim is for weight maintenance rather than reduction and will result in a demonstrable fall in BMI on their centile chart as height increases
How are most obese children managed (3)?
Changes in lifestyles
1. Healthier eating e.g. regular meals, nutrient-rich foods that are lower in energy and glycaemic undex, increasing fruit and veg intake etc
2. Increase physical activity by walking/cycling for transport, playing, household chores.
At least 60 minutes of moderate or greater intensity physical activity is recommended each day
3. Limiting Tv and other screen recreational activity to less than 2 hours a day
When do children have drug treatment/surgery for obesity?
What drug/surgeries are available?
Drug treatment can be given to children over 12 years with extreme obesity (BMI>40kg/m2) or have a BMI over 35kg/m2 and complications of obesity
-Orlistat, a lipase inhibitor
Bariatric surgery - only considered in children or young people if they have almost achieved maturity, have very severe or extreme obesity with complications e.g. T2DM
What are some complications associated with obesity (8)?
3. Gallbladder disease/gallstones
5. Orthopaedic problems e.g. SUFE, bow legs etc
7. Hypoventilation syndrome - snoring, OSA
8. Psychological sequele e..g low self-esteem, depression
What are some syndromes associated with obesity in children (3)?
2. Cohen - retinal dystrophy, progressive high myopia (nearsightedness), acquired microcephaly,
Non-progressive mental retardation, global developmental delay, hypotonia, joint hyperextensibility
3. Bardet-Biedl Syndrome - obesity, retinitis pigmentosa, polydactyly, hypogonadism, and renal failure in some cases
How common is type 1 and type 2 diabetes in children?
98% have T1 but the number with T2 is increasing
What are the presenting features of T2DM in children (5)?
1. Persistent hyperglycaemia (random plasma glucose more than 11 mmol/L)
2. Typical symptoms such as: thirst, polyuria, blurred vision, weight loss, recurrent infections, and tiredness are not usually severe and may be absent
3. Risk factors for type 2 diabetes (such as a strong family history, obesity, or Black or Asian origin)
4. Evidence of insulin resistance (for example acanthosis nigricans)
5. No additional features of type 1 diabetes or diabetes secondary to a pathological condition or disease, drug treatment, trauma, or pancreatic surgery
What is the management of T2DM in children (6)?
1. Make sure the child and family have an ongoing integrated package of care provided by a multidisciplinary paediatric diabetes team
2. A continuing programme of education
3. Encourage them to have immunisations against:
4. Manage lifestyle issues
5. Screen for complications of T2DM
6. Encourage them to attend clinic 4x a year as regular contact is associated with optimal blood glucose control
What is the genetics of Prader-Willi syndrome (2)?
1. ~70% of cases occur when part of the father's chromosome 15 is deleted.
2. In another 25% of cases the person has two copies of chromosome 15 from their mother and none from their father.
What are the clinical features of Prader-Willi syndrome (6)?
1. A constant desire to eat food, which seems driven by a permanent feeling of hunger and can easily lead to dangerous weight gain
2. Restricted growth, leading to short stature
3. Reduced muscle tone (hypotonia)
4. Learning difficulties
5. Lack of sexual development
6. Behavioural problems, such as temper tantrums or stubbornness
What are the changes in thyroid hormone levels from fetal life to after birth (4)?
1. Only a small amount of thyroxine is transferred from mother to fetus
2. Fetal thyroid mainly makes reverse T3 which is largely inactive
3. After birth, there is a surge in TSH, accompanied by a marked rise in T4 and T3 levels
4. TSH levels decline to normal adult levels within a week
Why is the detection of congenital hypothyroidism important (2)?
1. It is common
2. It is a preventable cause of severe learning difficulties
What are the clinical features of congenital hypothyroidism in children (8)?
Usually asymptomatic and picked up on screening
1. Faltering growth
2. Feeding problems
3. Prolonged jaundice
5. Pale, cold, mottled dry skin
6. Hoarse cry
7. Coarse facies
8. Delayed development
What are the clinical features of acquired hypothyroidism in children (8)?
1. Short stature/poor growth
2. Cold intolerance
3. Dry skin
4. Cold peripheries
6. Thin, dry hair
8. Slow-relaxing reflexes
What are the main causes of congenital hypothyroidism (4)?
How common are they?
1. Maldescent of the thyroid and athyrosis - most common cause of sporadic congenital hypothyroidism
3. Iodine deficiency - most common cause of congenital hypothyroidism worldwide but rare in UK
4. Hypothyroidism due to TSH deficiency - isolated TSH deficiency is rare and usually associated with pituitary dysfunction
What are the main causes of acquired hypothyroidism?
Usually caused by autoimmune thyroiditis
What is the treatment of hypothyroidism in children?
Lifelong thyroxine should be started before 2-3 weeks of age to reduce risk of impaired neurodevelopment
What is the main cause of hyperthyroidism in children?
Graves disease - secondary to the production of thyroid-stimulating immunoglobulins (TSI)
What are the clinical features of hyperthyroidism in children (10)?
Similar to adults but eye features are less common
2. Increased appetite
5. Weight loss
6. Rapid growth in height
8. Tachycardia, wide pulse pressure
9. Goitre (bruit)
10. Learning difficulties behaviour problems
How is congenital hypothyroidism tested for?
Detected on routine neonatal biochemical screening (Guthrie test) - identifies a raised TSH in the blood
What group of children does hyperthyroidism most common present in?
What investigations would be done and what would they show for hyperthyroidism?
Elevated levels of T4 and/or T3
TSH levels suppressed
Antithyroid peroxismal antibodies may be present
What is the management of hyperthyroidism?
1. Carbimazole or propylthiouracil
2. b-blockers can be given for anxiety
Medical treatment given for 2 years, which controls the thyrotoxicosis, however the patient usually relapses.
A second course of drugs can be given or an option for permanent remission can be done:
1. Radioiodine treatment
2. Subtotal thyroidectomy
What is diabetes insipidus?
Antidiuretic hormone insufficiency leading to large amounts of urine being produced
What are the clinical features of diabetes inspidus (3)?
2. Excessive thirst although some children are unable to recognise thirst
3. May present with hypernatraemia
Which children are at risk of diabetes insipidus (2)?
1. Severe illness
2. Neurosurgery - presents with hyponatraemia
What is gynaecomastia?
What are its clinical features?
Breast development in males - soft, compressible, and mobile subcutaneous chest tissue palpated under the areola of the nipple in contrast to softer fatty tissue
What are the causes of gynaecomastia (7)?
1. Physiological changes - increase in oestrogen and decrease in androgen, or natural decline in testosterone
2. benign pubertal changes
In rare cases:
4. Klinefelter syndrome
5. Certain cancers
6. Endocrine disorders
7. Various medications