A child with diabetes mellitus Flashcards
Congenital Hypothyroidism - pathophysiology
- After birth, there is a surge in TSH level leading to transiently raised T3, T4, normalises within a week
- Congenital hypothyroidism • 1:4000
- Preventable cause of severe learning difficulties
How is Congenital Hypothyroidism detected?
- Guthrie test at D5 of life
- Screening for raised TSH
- Pituitary abnormalities will not be picked up (as TSH may be low)
Congenital Hypothyroidism - causes
Maldescent of thyroid gland
• Failure of migration of thyroid from base of tongue to below the larynx • Thyroid may fail to develop partially or fully
Dyshormonogenesis
• Inborn error of thyroid hormone synthesis • Commoner in consanguineous marriages
Iodine deficiency – uncommon in UK
TSH deficiency
• Rare
• Pituitary dysfunction
• Other hormonal deficiencies may be associated too
Congenital Hypothyroidism - Clinical features
- Faltering growth
- Feeding problems
- Prolonged jaundice
- Constipation
- Pale, cold, mottled skin • Coarse facies
- Large tongue
- Hoarse cry
- Umbilical hernia
- Delayed development
what is the cause of Acquired hypothyroidism?
- Usually caused by autoimmune thyroiditis
- Uncommon
- Increased risk in children with Down’s syndrome/Turner syndrome
- May be associated with other autoimmune disorders e.g. Vitiligo, rheumatoid arthritis, diabetes mellitus
Acquired hypothyroidism - Clinical features
- Females > Males
- Short stature/ Poor growth
- Cold intolerance
- Dry skin
- Bradycardia, cool peripheries • Thin hair, loss of eyebrows
- Goitre
- Slow-relaxing reflexes
- Constipation
- Delayed puberty
- Learning difficulties
- Obesity
Management of congenital hypothyroidism
- Life long thyroxine
* Titrate to maintain normal growth, TSH and T4 levels
Pathophysiology of childhood Hyperthyroidism
• Usually secondary to autoimmune thyroiditis (Grave’s ds) due to antibodies
• Raised T3/T4, Very low TSH
• If Thyroid Peroxisomal antibodies present – may eventually lead
to hypothyroidism
• Neonatal hyperthyroidism may occur due to transplacental transfer of antibodies - transient
Treatment of childhood Hyperthyroidism
- Treatment
- Carbimazole or Propylthiouracil
- B-blockers for symptomatic relief of anxiety, tachycardia • Radio-iodine may be considered
- Surgery
Clinical features of childhood hyperthyroidism
- Anxiety
- Tremor
- Tachycardia
- Increased appetite
- Weightloss
- Diarrhoea
- Advancedbonematurity
- Warmperipheries
- Goitre
- Learningdifficulties
- Exophthalmos
- Lid lag
- Ophthalmoplegia • Lid retraction
What is the function of PTH?
• PTH
Parathyroid disorders
• Promotes bone formation via osteoblasts
• When calcium is low:
• PTH promotes bone resorption via osteoclasts • Promotes calcium absorption
• Activates vitamin D
Biochemical features of Parathyroid disorders
Hypoparathyroidism Serum calcium Low Serum phosphate Raised PTH Very low
Pseudohypoparathyr oidism Serum calcium Low Serum phosphate Raised PTH Normal or high
Pseudopseudohypop arathyroidism
Normal
Normal
Normal
Hyperparathyroidism Serum calcium High Serum phosphate Low PTH High
Management of Hypocalcemia
- 10%calciumgluconate
* Oral calcium supplements with vitamin D
Management of Hypercalcemia
- Rehydration
- Diuretics
- Bisphosphonates
Congenital Pituitary disorders
- Congenital • Structural
- Mid-linedefects
- Septo-optic dysplasia • Pituitary hypoplasia
Acquired Pituitary disorders
- Braintumours
- Craniopharyngioma • Cranial irrardiation
- Trauma
- Infection
- Infiltration
- Structural
- Hydrocephalus
- Diabetesinsipidus • ADH deficiency
Presentation of Congenital Adrenal Hyperplasia
- Insufficient cortisol & mineralocorticoid secretion
- Autosomalrecessive
- Presentation
- Ambiguousgenitalia
- Salt-losing crisis (low Na, high K)
- Hypotension
- Hypoglycaemia
- Metabolic acidosis
Treatment of Congenital Adrenal Hyperplasia
- Treatment
* Lifelonggluco-corticoids+/- mineralocorticoids
Addison’s disease Causes
- Autoimmune
- Haemorrhage/ Infarction
- X- linked adrenoleukosytrophy • TB
- Pituitary dysfunction
- Disease process
- Hypothalamus-pituitary-adrenal suppression due to long term steroid therapy
Addison’s disease - Presentation
Acute • LowNa • HighK • Hypoglycaemia • Dehydration • Hypotension • Growth failure • Circulatory collapse
Chronic
• Vomiting
• Lethargy
• Brown pigmentation (gums, scars, skin creases)
Diagnosis of Addison’s disease
- Lab parameters
- Metabolic acidosis
- Plasma cortisol is low • ACTH is high
- Synacthen test – plasma cortisol remains low
- In primary adrenal dysfunction
- In long-standing pituitary/hypothalamic dysfunction • Normal response excludes adrenal insufficiency
Management of Addison’s disease
- Life long glucocorticoids • Hydrocortisone
- Mineralocorticoids • Fludrocortisone
- Monitoring of growth
- 17 α-hydroxyprogesterone levels
- Sick day rules
- Adrenal crisis
- Emergency treatment with fluids and steroids
Cushing syndrome Clinical features
- Usually due to long-term glucocorticoid treatment
- Clinical features
- Growth failure
- Face and trunk obesity • Flushed cheeks
- Hirsutism
- Striae
- Hypertension
- Muscle wasting
- Psychological issues
causes of Delayed puberty
- Girls – 14yr Boys – 15yr
- Causes
- Familial (commonest)
- Low gonadotrophin secretion
- Systemic disease
- Hypothalamo-pituitary disorders
- High gonadotrophin secretion
- Chromosomal abnormalities (Klinefelter’s, Turner’s) • Steroid hormone enzyme deficiencies
- Acquired gonadal damage
