Endocrine Flashcards
Diagnosis diabetes
Symptomatic + random glucose >11, fasting >7 or 2hr test >11
Asymptomatic + venous sample in diabetic range + confirm with repeat test another day (random/fasting/2h)
The two insulin regimes
Twice daily (2/3 before breakfast and 1/3 pre dinner, both are split 1/3 short acting and 2/3 medium acting)
Multiple dose pen injection (basal background in eve and short acting pre meals)
What advice should be given about exercise in diabetic child
Sugary snack before
When should blood glucose be monitored more closely in children?
When ill
What is the dawn phenomenon
Increase in glucose at 4am due to GH surge
What is somogyi phenomenon
Insulin extra given to counteract dawn phenomenon- rebound hyperglycaemia
How do you know how dehydrated the child is in DKA
pH <7.1= 10%
> 7.1 = 5%
Paediatric DKA Rx
Bolus 10ml/kg if shocked
maintenance and defecit fluids 0.9% saline
Insulin 0.01-0.1u/kg/h infusion after the first hour of fluid (to reduce glucose at a rate of <5mmol/h)
Add potassium when electrolytes back (40mmol/L)
When glucose <12 change the fluid to 0.9% saline and 5% dextrose
Most common cause ambiguous genitalia
Congenital adrenal hyperplasia
What is true hermaphroditism
Genetic e.g. chimeric 46XX/XY
What could cause virilisation of a female foetus?
Maternal androgens e.g. ingested or tumour
How is sex determined in a foetus
Y chromosome has SRY gene that = gonads –> testes. If absent, they become ovaries
What is congenital adrenal hyperplasia
Autosomal recessive
Affect synthesis of adrenal steroids
Low cortisol=ant pit secretes more ACTH=more adrena androgens produced=virilisation of female foetus
90% congenital adrenal hyperplasia caused by what
21-hydroxylase deficiency
How might congenital adrenal hyperplasia present
Adrenal (salt losing) crisis 1-2w
Precocious puberty in boys
Cliteromegaly in girls
HTN
Tall stature child/short as adult
Hirsutism
Old bone age
skin hyperpigmentation
What type of congenital adrenal hyperplasia presents as intersex boys but non-virilised girls
17-hydroxylase defic
If Dx congenital adrenal hyperplasia antenatally what can you do?
Give maternal dex to reduce chance of virilisation of foetus
Precocious puberty ages
<8 girls
<9 boys
FSH and LH high or low in gonadotrophic dependent precocious puberty?
High, central control, premature activation of HPG axis
FSH and LH high or low in gonadotrophic independent precocious puberty?
Low, peripheral cause
Which type of precocious puberty is likely to have an unusual progression e.g. isolated thelarche
Pseudo/gonadotrophic independent
Bilaterally enlarged testes suggests what cause of precocious puberty
IC lesion releasing gonadotrophin
Unilat enarlged testes suggests what cause of precocious puberty
Gonadal tumour
Small testes suggests what cause of precocious puberty
Adrenal
Female precocious puberty is usually..?
idiopathic, familial, not worrying
precocious puberty cause with cafe au lait spots and polyostic fibrous dysplasia?
McCune Albright syndrome
First sign of female puberty
Breast development
First sign of male puberty
Testicular enlargement
When do female pubertal growth spurts occur?
Breast stage 3 (no nipple contour separation)
When do male pubertal growth spurts occur?
At testicular volume 10-12mL
What four things are used to determine a boy’s stage of puberty?
Genitals 1-5
Pubic hair 1-5
Axillary hair 1-3
Testicular volume 2-25mL
What four things are used to determine a girl’s stage of puberty?
Breast 1-5
Pubic hair 1-5
Axillary hair 1-3
Menarche
What ages = delayed puberty
Girls by 13
Boys by 14
Boys or girls delayed puberty more common? What is most common cause
Boys
Constitutional
Causes of delayed puberty with low gonadotrophin secretion
Short stature:
- Constitutional
- Hypothyroid
- Malnutrition
- Prader-willi
Normal stature:
-Prolactinoma
Kallman’s (no sense of smell)
Causes of delayed puberty with high gonadotrophin secretion
Short stature: Turner’s
Normal stature: Klinefelters (47XXY) or Gonadal disease e.g. torsion, trauma, RT
Raised TSH and low thyroxine is what type of hypothyroid
Primary
cause of 90% congenital hypothyroid?
Thyroid dysgenesis- aplasia or ectopic
How does a baby with congenital hypothyroid present
Goitre
Wide spaced eyes, flat nasal bridge, macroglossia
Large fontanelle
Short, broad fingers
Dry skin
Hypotonic
Constipation and abdo distentino, unconj jaundice
Cardiomegaly/brady/murmurs
Hoarse cry, feeding probs, apnoea/noisy resp
Sleepy
Mental slowness
How and when do you test for congenital hypothyroid
Guthrie test at 5days (TSH >100)
Causes of primary acquired hypothyroid
Thyroiditis (hashimotos or atrophic autoimmune)
Iodine defic
RT due to leukaemia or lymphoma
How does acquired hypothyroid present
Growth decel
Delayed ossification
Dry skin and hair
Lat 1/3 eyebrow lost
Low energy
Mental slowness
Constipation
Cold intolerance
Phenylketonuria is a defect in what?
phenylalanine breakdown (involving phenylalanine hydroxylase)
If untreated phenylketonuria leads to what?
Slowly progressive mental retardation
Spastic cerebral palsy
Hyperactivity
Athetosis
Acquired microcephaly
Fair hair, skin and blue eyes
Test for phenylketonuria?
Guthrie test showing raised phenlyalanine levels
What is the Guthrie test?
5 days old heel prick screening for:
S gh ickle cell
CF
Congenital hypothyroidism
6 metabolic diseases including phenylketonuria
How do you calculate expected height from parental height?
Boys:
((Mothers height + 12.5) + father’s)/2
Girls:
((Father’s height - 12.5) + mother’s)/2
How is bone age useful in short stature?
Idea of skeletal maturity. Delayed bone age w/o pathology means they will grow more
What growth velocity requires investigation
<25th centile
What height = short stature
<2nd centile
Causes of short stature
- Familial
- Constitutional
- Psychosocial deprivation
- Chronic illness/malnutrition
- Endocrine- GH defic, hypothyroid, PHP and PPHP, cushing’s
- Chromosomal- Turners, downs, prader willi
- IUGR (Russell-Silver synd)
- Achondroplasia
Which causes of short stature can be treated with GH injections
GH deficiency
Turners
IUGR
Prader Willi
When is it FTT
height/weight <2nd centile or cross down 2 centiles
Weight faltering suggests what?
Psychosocial
Reasons for FTT
Inadequate intake (available food, breastfeeding technique, anorexia, meal time behaviour, low SES)
Inadequate retention (vom, gord)
Malabsorption (coeliac, CF, CMPI, short gut synd)
Can’t use the nutrients (sydromes, T21, prem, storage disorders, IUGR)
Increased requirements (thyrotoxicosis, CF, malignancy, chronic infection, renal failure, heart disease)
History in FTT
Food diary
What happens at meal times
Child well? Energy?
Lethargy/D+V/cough
Prem? IUGR? birth probs? Meconium
Family growth and FHx
Which short child should be reviewed by GP and which by paeds?
<2nd centile GP
<0.4 Paeds
What tool is used to define obesity in children
BMI percentile charts adjusted to age and gender
Primary amenorrhoea, no pubic hair, groin swellings suggests what?
Androgen insensitivity
Male karyotype but female phenotype
Groin swellings are undescended testes