Zusammenfassung der Ressource
parathyroid disorders
- PTH
- ++ bone formation via
osteoblasts (bone forming
cells)
- when Ca2+ levels low
- ++ bone
resorption via
osteclasts
- ++ renal uptake of Ca2+
- activate vit D metabolism
- ++ gut absorption of Ca2+
- hypoparathyroidism
- rare in childhood
- low serum
Ca2+
- Rx
- of symptomatic
hypocalcaemia
- iv 10% calcium gluconate solution
- must be dilated
- else extravasation of infusion->
severe skin damage
- chronic hypocalcaemia
- oral Ca2+
- high dose vit D analogues
- adjust dose to keep
plasma [Ca2+] just
under normal range
- avoid hypercalciuria
- can cause nephrocalcinosis
- so monitor urinary Ca2+ excretion
- PTH very low
- raised serum phosphate
- normal alkaline phosphate
- if severe ->
- muscle
spasm
- fits
- stridor
- diarrhoea
- common in premature infants
- can be a presentation of severe rickets
- other causes rare in childhood
- causes in infants
- congenital deficiency
- DiGeorge syn
- thymic aplasia
- defective immunity
- cardiac defects
- facial abnormalities
- in older children
- autoimmune disorder
- associated w/ Addison disease
- pseudohypoparathyroidism
- end organ
resistance to action
of PTH
- due to mutation
in a signalling
molecule
- normal or high PTH
- abnormal Ca2+ & phosphate levels (low?)
- clinical features
- short stature
- obesity
- subcutaneous nodules
- short 4th metacarpals
- learning
difficulties
- teeth enamel hypoplasia
- calcification of basal ganglia
- pseudopseudoparathyroidism
- PTH, Ca2+, phosphate all normal
- similar physical
features to
pseudoparathyroidism
- +ve fam hx of pseudohypo and pseudopseudohypo in
same kindred
- hyperparathyroidism
- -> high Ca2+ level->
- constipation
- anorexia
- lethargy
- behavioural effects
- polyuria
- polydipsia
- wrist radiograph
- bony erosions of
phalanges
- neonates & young kids
- assoc w/ rare genetic
abnormalities
- e.g. William syn
- later childhood
- secondary to spontaneously
occurring adenomas
- part of multiple
endocrine
neoplasia (MEN)
syndromes
- Rx of severe hypercalcaemia
- rehydration
- diuretics
- bisphosphonates