Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

extra 1 (e) > Growth, Endocrine and Metabolism 2 > Flashcards

Growth, Endocrine and Metabolism 2 Flashcards

1
Q

What is precocious puberty?

A

Early puberty
Girls = <8yr
Boys = <9yr

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Is precocious puberty concerning?

A

Usually benign in girls

Concerning in boys, rarely idiopathic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are two types of precocious puberty?

A

1) Central (true) = gonadotrophin-dependent

2) Peripheral = gonadotrophin-independent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is central precocious puberty?

A

Puberty beings as a result of early activation of the hypothalamic pituitary axis

Normal pubertal development follows

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are some causes of central precocious puberty?

A

Idiopathic - no cause found in 80% girls and 40% boys

CNS abnormalities:

  • Tumours eg gliomas, hCG-secreting germ cell tumours
  • CNS trauma or injury eg infection, radiation, surgery
  • Hamartomas of hypothalamus
  • Congenital disorders such as hydrocephalus and arachnoid cysts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is peripheral precocious puberty?

A

Puberty begins as a result of excess sex-steroids (androgens, oestrogen, progesterone) which do not involve physiological gonadotrophin secretion from the pituitary = independent of HPG axis

Gonad matures without GnRH stimulation and levels of testosterone and estradiol are elevated whilst LH and FSH are surpassed =abnormal pubertal development follows

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are some causes of peripheral precocious puberty?

A

1) Congenital adrenal hyperplasia (CAH)
2) Tumours
3) McCune-Albright syndrome
4) Silver-Russell syndrome
5) Testotoxicosis
6) Exogenous oestrogen or androgen exposure (therapeutic or accidental)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How may precocious puberty present in females?

A

1) Isolated pubic hair (pubarche)

2) Premature breast development (thelarche)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How may precocious puberty present in males?

A

Bilateral enlarged tests = gonadotrophin release

Unilateral enlarged tests = suggest gonadal tumour

Premature pubarche

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are hamartomas?

A

Mostly benign, focal malformation that resembles a neoplasm of its tissue of origin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is an arachnoid cyst?

A

CSF covered by arachnoidal cells and collaged that can develop between the surface of the brain and the cranial base, or on the arachnoid membrane (middle meningeal layer)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What tumours may cause peripheral precocious puberty?

A

hCG-secreting tumours:
- Liver = hepatomas / hepatoblastomas

  • Choriocarcinomas of gonad, pineal gland, mediastinum
  • Adrenal tumours (rare)

Ovarian tumours may cause masculinisation or feminisation

Testicular Leydig-cell tumours can cause early virilisation in men

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is McCune-Albright syndrome (MAS)?

A

A genetic condition in which there is increased risk of multiple endocrinopathies:

  • Thyrodoxicosis
  • Cushing’s syndrome
  • Acromegaly
  • Hyperparathyroidism etc
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are some signs of MAS?

A

Café-au-lait spots
Pathological fractures due to fibrous dysplasia of bones
Recurrent ovarian cysts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is testotoxicosis?

A

= Familial male precocious puberty

Autosomal dominant condition characterised by progressive pubertal changes, rapid physical growth, skeletal maturation and sexually aggressive behaviour in the first 2-3yrs of life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What investigations are done for precocious puberty?

A

1) Sex steroids
- Early morning testosterone is higher in boys in early puberty
- Estradiol levels are less reliable marker for puberty in girls as they are very variable (very high = ovarian pathology)

2) Gonadrotrophins LH and FESH
- Random LH useful for CPP
- Random FSH will not distinguish prepuberty from puberty

3) TFTs

4) Adrenal steroid precurorors
- If CAH suspected

5) HCG
- If hCG secreting tumour suspected

6) Imaging:
- Pelvic US
- MRI
- Hand and wrist x-rays for bone age

7) GnRH stimulation test
- Flat response in gonadotrophin-independent puberty

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the management of precocious puberty?

A

No management required for central

Surgical resection of tumours (will not regress pubertal changes)

GnRH agonists

Testolactone

Tamixofen in MAS

Ketoconazole (eg in testotoxicosis) inhibits steroid biosynthesis

Cyproterone acetate + flutamide = anti-androgen

Medroxyprogesterone = progesterone analogo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How to GnRH agonists help in precocious puberty?

A

Over-stimulate the pituitary, causing desensitisation and thus less release of LH and FSH

Continued until the time for normal puberty arrives

Used in CPPP, MAS, testotoxicosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does testolactone work?

A

= aromatase inhibitor thus inhibits steroid biosynthesis

Used most commonly for MAS but also used in testotoxicosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is delayed puberty?

A

Boys:
- Absence of testicular development (or a testicular volume lower than 4ml) by 14yr

Girls:
- Absence of breast development by 13yr, or primary amenorrhoea with normal breast development by age 15yr

= Most have simple constitutional delay in growth and puberty (CDGP and do not need investigation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Is CDGP more common in boys or girls?

A

Boys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are some causes of central delayed puberty (relating to hypothalamo-pituitary axis)?

A

Intact axis:

1) CDPG = most common but must rule out other causes
2) Chronic illness eg Crohn’s
3) Malnutrition eg CF
5) Excessive physical exercise
5) Psychological deprivation
6) Steroid therapy
7) Hypothyroidism

Impaired axis:

8) Tumours adjacent to axis eg pituitary tumour
9) Congenital abnormalities eg congenital panhypopituitarism
10) Irradiation treatment
11) Trauma
12) IHH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is IHH?

A

Idiopathic hypogonadotropic hypogonadism

= low gonadotrophin and sex steroid levels in the absence of abnormalities in hypothalamic-pituitary-gonadal system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What features may be seen in IHH?

A 
Cryptotorchordism
Micropenis
Synkinesia (mirror movements)
Cleft lip and palate
Dental agenesis
Skeletal anomalies
Hearing loss
 \+/- Loss of smell (Kallman's syndrome)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are some causes of peripheral delayed puberty in boys?

A

Bilateral testicular damage eg torsion / mumps

Syndromes causing cryptorchidism or gonadal dysgensis eg Prader-Wili

Irradiation

Drugs eg cyclophosphamide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are some causes of peripheral delayed puberty in girls?

A

Gonadal dysgenesis eg Turner

Irradiation

Drugs eg cyclophosphamide or busulfan (ovarian failure)

DSD eg CAH

PCOS

Toxic damage eg iron overload (thalassaemia) or galactosaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What investigations should be done for delayed puberty?

A

Usually not required as most are CDGP

Investigations for chronic disease:
FBC
Ferritin
Renal function tests 
U&amp;Es
Coeliac screen 
Urinalysis
Investigations for disorders of gonadal axis:
Chromosome analysis
Basal FSH/LH and estradiol/testosterone
TFTs
GNRH and GH
Pelvic USS
Bone age - wrist x ray
MRI/CT of pituitary
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What may LH and FHSH be in CDGP and IHH? And gonadal failure?

A

Low in CDGP and IHH

Elevated in gonadal failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the management of CDGP?

A

Not often necessary but short courses of sex steroid can help individuals catch up with peers

Boys: testosterone PO or depot injection for 3-6 months then reassess
- Usually rapid and effective

girls: gradually increasing oestrogen treatment, with cyclical progesterone once adequate oestrogen levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is given in primary testicular / ovarian failure?

A

Pubertal induction followed by ongoing hormone replacement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is congenital hypothyroidism?

A

Lack of thyroid hormones present from birth, if not detected early = irreversible neuroligcal problems and poor growth

  • some develop after birth = primary hypothyroidism rather than CH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Is CH more common in boys or girls?

A

2x more common in girls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Where is CH more common?

A

Areas with iodine deficiency eg Bangladesh / China / Peru

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What are some causes of CH?

A

1) Thyroid gland defects = 75%
- Not inherited so low chance of sibling affected

2) Disorders of thyroid metabolism = 10%
- Eg TSH unresponsiveness / defects in thyroglobulin structure
- Usually inherited

3) Hypothalamic or pituitary dysfunction = 5%
- Pituitary hypothyroidism usually occurs with other disorders of pituitary function if GH deficiency
- Hypothalamic causes include tumours, ischaemic damage etc

4) Transient hypothyroidism = 10%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is transient hypothyroidism usually related to?

A

Maternal medications eg carbimazole or maternal antibodies

In maternal thyroid disease, IgG auto-antibodies can cross the placenta and block thyroid function in utero - this improves after delivery

36
Q

What genetic defects have been associated with CH?

A

PAX8 - related to formation of kidney and thyroid gland

DUOX2 - related to production of thyroid hormones

37
Q

Why are infants with CH usually clinically normal at birth?

A

Presence of maternal thyroid hormones

38
Q

What symptoms may an infant with CH present with? (4)

A

1) Feeding difficulties
2) Somnolence (sleepiness)
3) Low freq of crying
4) Constipation

39
Q

What signs may an infant with CH present with? (15)

A

1) Large fontanelles
2) Myxoedema
3) Nasal obstruction
4) Macroglossia
5) Low temp (<35) with cold and mottled skin on extremities
6) Jaundice = prolongation of physiological jaundice
7) Umbilical hernia
8) Hypotonia
9) Hoarse voice
10) Cardiomegaly
11) Bradycardia
12) Pericardial effusion - usually asymptomatic
13) Failure of fusion of distal femoral epiphyses
14) Refractory anaemia
15) Goitre = more common with thyroid hormone resistance and transient hypothyroidism

40
Q

What is the appearance of a child with hypothyroidism?

A 
Short stature
Hypertelorism
Depressed bridge of nose
Narrow palpebral fissures 
Swollen eyes
41
Q

What causes myxoedema in hypothyroidism?

A

Connective tissue reacts to increased TSH levels

42
Q

How is CH diagnosed?

A

All babies are screened at birth via heel pinprick and analysed for TSH and T4 (Guthrie)
- High TSH and low T4 confirm diagnosis

Thyroglobulin levels

Thyroid USS or radionuclide scanning

43
Q

What is included in the UK Newborn Screening Programme?

A

TSH and T4
Phenylketonuria
CF
Sickle cell disease

44
Q

What is the management of CH?

A

Aim = early detection and early thyroid hormone replacement to avoid irreversible neurological disability

Lifelong thyroxine replacement with L-thyroxine given once daily and titrated to TFTs
- Levothyroxine 10-15mcg/kg/day

Regular monitoring

Transient hypothyroidism does not need to be treated unless low T4 and raised TSH last <2 weeks
- Treatment for this is usually terminated after 3-5 months

45
Q

What monitoring is required in CH?

A

TFTs
Growth charts
Achievement of childhood milestones
Mental development in all 4 areas = fine motor, gross motor, speech and language, social

46
Q

What is the most common form of acquired childhood hypothyroidism?

A

Lymphocytic thyroiditis = Hashimoto’s autoimmune thyroiditis

47
Q

When does Hashimoto’s autoimmune thyroiditis usually present?

A

Adolescence

48
Q

In what condition are there a high incidence of Hashimoto’s autoimmune thyroiditis?

A

Turner syndrome

Down’s syndrome

49
Q

What are the signs of Hashimoto’s autoimmune thyroiditis?

A

Slowing of growth
+ other hypothyroid symptoms eg skin changes, cold intolerance

Delayed puberty (younger children may have galactorrhea or precocious puberty)

50
Q

What is a particular issue with adolescents with Hashimoto’s autoimmune thyroiditis?

A

Poor compliance in medication

51
Q

What are some causes of Hashimoto’s autoimmune thyroiditis?

A

Iatrogenic eg treatment of hyperthyroidism

Suppurative thyroiditis

Subacute non-supperative thyroiditis = de Quervain’s disease

52
Q

What are causes of painless and painful thyroiditis?

A

Painful = caused by radiation/infection/trauma

  • Suppurative thyroiditis
  • De Quervain’s disease

Painless = AI or medication
- Hashimotos

53
Q

How common is childhood obesity?

A

1/10 children aged 4-5yr

1/5 children aged 10-11yr

54
Q

What are some contributory factors for childhood obesity? (8)

A

1) Poor dietary habits
2) Lack of exercise
3) Sleep deprivation
4) Genetics
5) Lower socio-economic status
6) Medication

Also:

7) High birth weight or low birth weight associated with catch-up growth
8) Intrauterine exposure to maternal gestational DM or obesity

55
Q

What endocrine disorders may cause obesity? (8)

A

1) Hypothyroidism
2) Cushing’s syndrome
3) GH deficiency
4) Muscular dystrophy and other causes of immobility
5) OCIS
6) Hypothalamic damage
7) Spina bifida
8) Genetic conditions eg Prader-Willi

56
Q

What medications may aggravate weight gain?

A

Antidepressants - mirtazapine, paroxetine, imipramine

Anticonvulsants - sodium valporate, gabapentin, vigabatrin and carbamazepine

Antipsychotics - clozapine, olanzapine, pimozide

Lithium

Corticosteroids

57
Q

What are good measures of obesity in children?

A

BMI not as useful as does not consider age, gender, puberty, race/ethnicity

Gold standard = densitometry or dual-energy X-ray absorptiometry (DEXA) scanning

58
Q

What BMI centiles are:

1) Overweight
2) Obese
3) Severely obese

A

1) Overweight = >91st
2) Obese = >98th
3) Severely obese = >99.6th

59
Q

What are some complications of obesity in children?

A

1) T2DM
2) Breathing problems eg sleep apnoea
3) Orthopaedic conditions
4) Non-alcoholic fatty liver disease
5) Psychosocial morbidity
6) PCOS
7) Metabloc syndrome
8) Vit D and iron deficiency

60
Q

What is phenylketonuria (PKU)?

A

Most common inborn error of amino acid metabolism

Absent / virtually absent phenylalanine hydroxylase (PAH) enzyme activity

This enzyme converts dietary phenylalanine to tyrosine

Products of this pathway are important in formation of catecholamines, neurotransmitters and melanin

61
Q

What does high plasma concentrations of phenylalanine in PKU cause?

A

Formation of byproducts phenylpyruvic acid and phenylethylamine

Neurotoxic above a certain threshold

62
Q

How may PKU present?

A

Usually normal at birth but picked up on newborn baby heel-prick screen

1) Very fair with blue eyes (compared to family)
2) Musty / ‘mousey’ odour
3) Developmental delay and general learning disability
4) Recurrent vomitting
5) Eczematous skin eruptions and scleroderma-like skin lesions
6) Seizures

63
Q

What are the types of PKU?

A

Type I
Type II
Malignant

64
Q

How is type I PKU inherited? Which chromosome?

A

Autosomal recessive

Chr 12

65
Q

What is type II PKU?

A

5% enzyme activity retained - less serious

66
Q

What is malignant PKU?

A

Deficiency in enzymes co-factor THB

= more severe

67
Q

What investigations are done for PKU?

A

Heel-prick blood assayed for phenylalanine >12hrs after birth

Blood levels of phenylalanine

Phenylketones detected in urine

68
Q

How is PKU managed?

A

Diet:

  • Low penylalanine
  • High tyrosine

Avoid milk, dairy, fish, chicken, beans, eggs, nuts

Regular monitoring of blood phenylalanine and its metabolites

69
Q

What are some complications of PKU? (4)

A

1) Developmental delay / intellectual disability if non-adherence to diet
2) Epilepsy
3) Severe behavioural disturbance
4) Congenital anomaly and intellectual disability in offspring of PKU mothers

70
Q

What are the 3 main groups of short stature?

A

1) Primary growth disorders - condition intrinsic to growth plate
2) Secondary growth disorders - growth plate changes as a consequence of the condition
3) Idiopathic

71
Q

What is the causes the majority of short statures?

A

CDGP
Familial growth stature
Idiopathic

72
Q

What are some primary growth disorders? (3)

A

1) Genetic syndromes:
- Down’s syndrome
- Prader-Willi etc

2) IUGR with failure to catch up:
- Prematurity
- Placental dysfunction

3) Congenital bone disorders:
- Achondroplasia
- Hydrochondroplasia
- Osteogenesis imperfecta

73
Q

What are some secondary growth disorders? (7)

A

1) Endocrine:
- Hypothyroidism
- Cushings
- GH deficiency
- Precocious puberty

2) Metabolic
- Glycogen storage disease

3) DM poorly controlled

4) Chronic disease:
- CV
- Resp eg CF
- Haemoglobinopathies
- JA

5) Malnutrition:
- IBD
- Coeliac
- Rickets

6) Psychosocial deprivation
- Hyperphagic short stature syndrome

7) Medication
- Steroid therapy

74
Q

What is important to determine regarding height in a child with a short stature?

A

Determine if there is steady growth behind centiles (more likely to be constitutional or maturational delay)

or if there is a fall-off in growth across centiles (more likely to be chronic illness or acquired hypothyroidism)

75
Q

What is important to include on examination of a child with a short stature?

A

Height and weight
- inc sitting and standing height to consider skeletal disproportion eg achondroplasia

GH deficiency

  • Look for other features of pituitary deficiency eg hypogonadism
  • Or features of pituitary tumour eg bitemporal hemaniopia

Features of Cushing’s, CKD, hypothyroidism, fetal alcohol syndrome, Turner syndrome

Skeletal causes
- Eg rickets = craniotabes, bulbous wrists and bowing of extremeties

Skin lesions

  • Café-au-lait (McCune-Albright syndrome)
  • Large hemaniomas
76
Q

How is expected final height calculated?

A

Mid-parental height

77
Q

How is mid-parental height used to calculate expected height in boys?

A

Mid parental height =

(fathers height + (mothers height + 13)) /2

78
Q

How is mid-parental height used to calculate expected height in girls?

A

Mid parental height =

((fathers height - 13) + mothers height) /2

79
Q

What investigations should be done for short stature?

A

Bloods - FBC, renal function, LFTs, TFTs, ESR, CRP, urinalysis

Karyotyping

Specific tests eg CF

Bone age

Dental age

80
Q

What is bone age?

A

Predicts final adult height by estimating skeletal maturation from an assessment of the ossification of the epiphyseal centres

81
Q

How is bone age measured?

A

Radiograph L hand and wrist using standards from standards from Greulich-Pule atlas

82
Q

When is bone age considered delayed?

A

Two standard deviations below chronological age

83
Q

What is the management of short stature?

A

Depends on cause

Growth hormone = somatropin

Can be used in:

  • GH deficiency
  • Prader-Wili
  • CKD
  • SGA with subsequent growth failure at 4yrs or later
84
Q

What should be considered in hx of short stature?

A

FH
- Parental growth rate, early/late puberty/menarche

SH
- neglect

DH
- Steroids

+ BIND !!!!!

Birth history

  • Antenatal illness/drugs
  • Gestational age

Immunisations

Neonatal

  • Birthweight
  • Illnesses

Developmental
- Goals met/ delayed

85
Q

What should be plotted in short stature?

A

Height
Weight
Head circumference

= plot growth chart

extra 1 (e) (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions