endocrine Flashcards
inheritance of congenital adrenal hyperplasia
autosomal recessive
cause of CAH
- block in production of 21 hydroxylase
- accumulation of 17 alpha hydroxyprogresteron
- converted to androgens to cause virilisation
- causes adrenal hyperplasia
- also leads to reduced aldosterone production -> salt losing crisis
aldosterones function
- retains sodium in kidney so increase sodium in blood and then retain water -> increases bP
- increase excretion of potassium in urine
presentation of CAH
GIRLS -> ambiguous genitalia, amenorrhoea
BOYS -> hyperpigmentation and penile enlargement, precocious puberty
salt losing crisis -> vomiting, hypotension, dehydration
investigations for CAH
- raised 17 hydroxy- progesterone
- hyponatraemia
- hyperkalaemia
- metabolic acidosis
+ USS pelvis, karyotype, hypoglycaemia
management of CAH
- hydrocortisone
- fludrocortisone
causes of hypothyroidism
- thyroid agenesis
- ectopic gland * (common in developing countries)
- Hashimotos (autoimmune)
- iodine deficiency (most common worldwide)
presentation of Graves disease
- chemosis (swelling of conjunctiva)
- exopthalmosis (bulging eyes)
- pretibial myxoedema
presentation of neonatal hypothyrodisim
present at 6 weeks old…
- poor feeding
- prolonged jaundice
- hypotonoia
- constipation
- macroglossia
- pale, mottled skin
investigations for graves disease
TSH receptor antibodies **
TPO antibodies
investigations for hashimotos
TPO antibodies *** (95%
thyroglobulin antibodies (60-80%
thyrotropin receptor antibodies)
presentation of hashimotos
painless goitre
investigations for hypothyroidism
- newborn screening - TSH >10
- T4 low
- tSH high
- thyroid USS - if dysgenesis/ agenesis/ cysts
complications of untreated hypothyroidism
spasticity
significant learning difficulties
dysarthria
developmental delay
causes of hyperthyroidism
- GRaves disease ***
- neonatal thyrotoxicosis - babies born to mothers with Graves, check TFTs on day 5
3.thyroid carcinoma - papillary or follicular - pituitary adenoma
investigations for hyperthyrodiism disease
- high T4
- low TSH
- USS
- graves - TSH antibodies
management of hyperthyroidism
carbimazole (SE - GI upset, agranulocytosis)
radio-iodine therapy
anatomy and role of adrenal gland
ADRENAL CORTEX
glomerulosa - aldosterone
fasciculata - cortisol
reticularis - androgens
ADRENAL MEDULLA
- adrenaline
causes of cushings syndrome
- adrenal adenomas - causes cortisol overproudction
- pituitary tumours - excess ACTH
- exogenous steroids
- syndromes e.g. MEN1, McCune Albright
presentation of cushings syndrome
- central weight gain
- buffalo hump
- depression
- risk of diabetes
- moon facies
- muscle weakness
- striae, easy bruising
investigations for cushings syndrome
- 24 hour urinary free cortisol levels - increased
- serum ACTH
- dexamethasone suppression test -give steroid at night, if 9am cortisol suppressed, pituitary ACTH cause.
- MRI head
management of cushings syndrome
trans sphenoidal removal of tumour
causes of adrenal insufficiency
PRIMARY
- congenital adrenal hyperplasia
- addisons disease
- familial glucocorticoid deficiency
SECONDARY
- long term steroid withdrawal
- hypopituirism
- severe illness/ in PICU
presentation / features of addisons disease
- weakness
- hyperpigmentation (of gingiva)
- dizziness
- salt craving
- weight loss
- low mood
investigations for addisons disease
- synacthen test
- hyperkalaemia
- hyponatraemia
- metabolic acidosis
test for low cortisol / adrenal cortisol insufficiency
SYNACTHEN TEST
- measure cortisol -> give synacthen (ACTH) -> repeat cortisol 1 hour after
- no rise in cortisol = primary adrenal failure
- rise in cortisol = ACTH problem
management of addisonian crisis
- IV fluids
- IV hydrocortisone
what is diabetes insipidus
deficiency of AVP causing high volumes of high volumes of dilute urine and hypernatraemic dehydration
central causes of diabetes insipidus
1.craniopharyngioma
2. germinoma
3. traima
4. post radiotherapy
5. aneuryms/ haemorrhage / sickle cell
nephrogenic causes of diabetes insipidus
- CKD
- inherited e.g. x linked nephrogenic DI
- pregnancy
- medications e.g lithium, orlistat, ofloxacin
presentation of diabetes insipidus
dilute excess urine
polydipsia
dehydration
investigations for diabetes insipidus
- urine osmolality - low (<750)
- serum osmolality - high (>295)
- hypernatraemia
- MRI brain
test to confirm causes of diabetes insipidus
water deprivation test
- child weighed and deprived of water for 7 hours + measure osmolality
- give desmopressin
- if increase in urine concentration -> central DI causes
if no increase in urine conc -> nephrogenic cause
what is SIADH
excess secretion of ADH (inserts more aquaporin 2 channels into collecting ducts) causing retention of water and leading to dilutional hyponatraemia and reduced serum osmolality
cause of SIADH
- tumours e.g brain, small cell lung Ca, ewings sarcoma
- CNS disorders e.g. haemorrhage, infections, trauma
- pneumonia
- medications e.g. thiazine diuretics, SSRIs
presentation of SIADH
- headache
- confusion
- lethargy
- muscle cramps
investigations for SIADH
- urine osmolality - high
- serum osmolality - low
- hyponatraemia
management of SIDAH
- fluid retention
- vasopressin receptor antagonist e.g. tolvaptan
- hypertonic saline
management of Diabetes insipidus
central - desmopressin + water
nephrogenic - thiazide diuretics + water
what is phaeochromocytoma
neuroendocine chromaffin cell tumour in the adrenal medulla
presentation of phaeochromocytoma
- palpitations
- sweating
- headache
- severe hypertension
- diarrhoea
investigations to diagnose phaeochromocytoma
urine catechloamines - VMA/ HMA
management of phaeochromocytoma
- alpha adrenoreceptor blocker pre surgery
- surgical removal
features of MEN type 1
- pituitary adenoma
- parathyroid hyperplasia
- pancreatic islet cell tumour
features of MEN type 2
- pituitary adenoma
- parathyroid hyperplasia
- medullary thyroid cancer
- phaeochromocytoma
- mucosal neuroma
presentation of craniopharyngioma
- GH deficiency
- diabetes insipidus
- visual impairment e.g. bitemporal hemianopia
- headache
- behavioural change, irritable
mechanism of parathyroid hormone
- low calcium
- parathyroid hormone released from chief cells
- activates kidney to increased calcium reabsorption and increase phosphate excretion
- activates small intestine to reabsorb more calcium
- stimulates osteoblasts so calcium released from bone
causes of hypoparathryoid
- removal of thyroid gland
- Digeorge
- Magnesium deficiency
- vit D deficiency
- pseudo- hypoparathyroid(mutation in GNAS gene)
blood tests for hypoparathyroid
- low PTH
- low calcium
- increase phosphate
causes of hypercalcaemia
- hyperparathyroid
- sarcoidosis
- TB
- williams syndrome
5.vit D therapy
signs of hypocalcaemia
- seizures
- paraesthesia
- tetany
- carpal spasm (trousseus sign)
- paraesthesia
pathophysiology of type 1 diabetes
destruction of beta cells in islets of langerhans by…
1. glutaric acid decarboxylase antibodies
2. insulin antibodies
3. islet autoantigen 2 antibodies
causing absolute insulin deficiency
causes of type 1 diabetes
- autoimmune
- DR3/DR4
- family history
- downs syndrome, cystic fibrosis
diagnosis of type 1 diabetes
- fasting blood sugar - >7 mmol/l
- random blood sugar >11.1mmol/l
- 2 hour plasma conc >11.1mmol/l 2 hours after 75g glucose in OGTT
target blood sugars in diabetes
4-7 = waking, before meals
5-9 = after meals
tests to do in type 1 diabetes
- anti- GAD antibodies
- HbA1c
- anti TTG
- TFTs
- U&E, urine creatinine ratio
- vit D and calcium
- triglycerides
management of type 1 diabetes
BASAL/BOLUS REGIME
- long acting insulin = 40% daily dose e.g. glargine, detemir
- short acting insulin = 60% daily dose e.g. aspart, lispro
CONTINUOUS INSULIN PUMP
- regular rapid acting insulin via s/c
- Resisted every 2-3 days
annual screening in type 1 diabetes
- urine albumin: creatinine ratio (from 12 y/o)
- blood pressure
- TFT
- diabetic eye screening
- HbA1c
DKA criteria
- hyperglycaemia >11
- ketones >3
- metabolic acidosis ph <7.3
management of DKA
- 10ml/kg saline bolus over 60 mins (if shocker 20mls/kg)
- fluid deficit - initial bolus (over 48 hours) + fluid maintenance (over 24 hours)
- fixed insulin 0.1 units/kg/hour + long acting insulin
severity of DKA
mild ph 7.2-7.29 = 5% dehydration
moderate 7.1 - 7.19 = 7% dehydration
severe = ph <7.1 = 10% dehydration
complications of DKA
- cerebral oedema - within 1st 12 hours, headache, irritable, reduced GCS
- Hypokalaemia
- hypernatraemia
- aspiration pneumonia
- pneumothorax
management of cerebral oedema in DKA
- 20% mannitol 1g/kg over 10-15 mins
- hypertonia saline 3%
monitoring of type 2 diabetes
HbA1c every 3 months (target <48)
management of type 2 diabetes
- weight loss, life style adaptations
- S/R metformin
presentation fo mODY
well non obese children with mildly raised blood sugars
types of MODY
type 1 (HNF4-alpha)
- low dose sulfonylureas
type 2 (GCK gene)*
- asymptomatic, no treatment
type 3 (HNF1-alpha) **
- low dose sulfonylureas
type 4
type 5 (HFN1B)
- renal cysts, low magensium, high uric acid and pancreatic atrophy
tests for mODY
- slightly elevated blood sugar
urine c peptide creatine ratio
genetic testing*
when does puberty start for girls
8 - 14 y/o
1st sign of puberty in girls
- breast development **
- pubic and axillary hair growth
- menarche - usually 2-3 years after breast bud development
- increased height velocity
when does puberty start for boys
9 - 14 y/o
1st sign of puberty in boys
1.testicular enlargement >4mls **
2. pubic hair growth
3. penile and scrotal enlargement - 1 year after testes enlargement
4. growth spurt
5. deep voice, acne
tanner stages of development
1 - pre adolescent
2 - enlargement of testes and scrotum
3 - further growth , enlargement of penis
4. increase in breadth of penis and development of glans
5. adult genitalia
define precocious puberty
secondary sexual characteristics before 8 y/o in girls and before 9 y/o in boys
causes of precocious puberty
CENTRAL (gonadotropin dependent, increase FHS/LH, same physiological pattern)
- idiopathic - girls
- hydrocephalus
- hypothalamic hamartoma
- craniopharyngioma/ tumours
- NF1
- intracranial haemorrhage
PERIPHERAL (gonadotropin independent, excess androgen secretion, virilisation but no increase in testes volume)
- congenital adrenal hyperplasia
- adrenal tumours
- russel silver
-McCune Albright syndrome - exogenous steroids
management of precocious puberty
- pelvis USS
- hand and wrist XR - assess bone age
- GnRH anologues - suppress gonadotropin secretion
define delayed puberty
onset of sexual development > 13 y/o in girls and >14 y/o inboys
causes of delayed puberty
- constitutional delay - benign
- chronic illness e.g. malnutrition, CKD
- genetic syndromes e.g Kallmanns, turner syndrome, prader willi, klinefelters
- hypothyrodid
- gonadal dysgenesis
6.prolonged steroid use
presentation of polycystic ovary syndrome
- hirsuitism, acne
- irregular menses
- weight gain
- depression, mood swings
- acanthosis nigricans
complications = infertility, CV disease, type 2 diabetes, OSA, endometrial CA
diagnosis of polycystic ovary syndrome
- increased testosterone
- reduced sex hormone binding globulin
- USS ovaries
How to calculate mid parental height
(dads height + mums height ) /2
- 7cm = girls
+7cm = boys
or (dad height + mum height +/- 13cm) /2
causes of short stature
- constitutional delay - deceleration in 1st 3 years of life, normal during childhood, delayed bone age
- familial short stature - normal bone age
- idiopathic
- genetics e.g. downs, russel silver, turners, noonans
- IUGR
- chronic disease e.g. CKD, coeliac, malnutrition, cardiac, glycogen storgae disorders
- endocrine e.g. hypothyroid, GH deficiency, IGF1 deficiency
8 psychosocial
presentation of GH deficiency syndrome
present <1 y/o with ..
- nystagmus
- reduced visual acuity
- micropenis
- reduced muscle bulk
- delayed bone age
presentation of hypopituitarism
- short stature
- delayed puberty
-round face, short neck - small hands and feet
- loss of body hair
- thin scalp hair
features of septo optic dysplasia
- agenesis of septum pallicudum + corpus callosum
- hypoplasia of optic nerve
- hypopituitarism
- developmental delay
calculate insulin sensitivity
100 / total daily dose of insulin
features of pseudo-hypoparathyroidism
high PTH (insensitive), low calcium, high phsophate
- round face
- short
- shortended 4th and 5th metacarpal
