Bone Flashcards
(16 cards)
what does PTH do?
increases CA
(dec in PO4)
- releases Ca from bone
- inc Ca absorp from gut
- inc Ca uptake from kidneys
what is the work up for short stature
cbc liver and renal panel ESR?CRP for implammatory TTG to rule out celiac TSH/FT4 carotene and folate for nutrition Ca/mg/PO4 Urine - RTA Bone age Karyotype for a girl
(IGF 1/IGF BP3
porlactin)
what are the CF of hypocalcemia
asymptomatic
msl: intermittent muscle cramps - at rest or during exercise, laryngospasm, tetany
CNS: SZ, papillodema, basal ganglia calcifcation
H&N: cataract, enamel hypoplasia
CVS: QTc and ST prolongation, arrythmia, HB
what are common causes of Vit D def
Lack of dietary intake Lack of sun exposure liver disease renal disease drugs - phenytoin. phenobar Vit D resistance
what are the 4 main causes of hypocalcemia
- Vit D def
- Malabsorption
- hypoparathyroidism - congenital or acquired
- pseudohypoparathyroidism - resistance to PTH
if pt has hypopartathyroidism, what will the PTH, Calcitriol, Ca and PO4 be
low PTH
low calcitriol
low Ca
high PO4
what are risk factors for Vit D def
exclusive BF mothers that are Vit def darker skin poor sun exposure northern communities
what are the 2 main groups of rickets?
hypocalcemic
hypophosphatemic
what are hypophosphatemic causes of rickets?
1) not enough PO4 going in: malnutrition, GI losses, antacids
2) too much out - congenital disorders, systemic illness
what are clinical features of rickets in the newborn
FTT
poor energy
muscle weakness
bone deformities and fractures
what are clinical features of Rickets
frontal bossing craniotabes delayed closure of fontanelles rachitic rosaries Harrison Groove enlarged wrists and ankles bowing
what are radiologic features of rickets
widening of distal ulna and radius
concave cupping
frayed and poorly demarcated ends
increased space of writs
what are the lab abnormalities of Vit D def
Vit D low Low/N Ca Low PO4 high PTH high ALP
what is Albright hereditary osteodystrophy
pseudohypoparathyroidism - resistance to PTH
High PTH but LOW Ca
short stature, round facies with a low nasal bridge, obesity, disproportionate shortening of the limbs (particularly brachydactyly of the third, fourth, and fifth metacarpals and first distal phalanx), heterotopic ossification, and intellectual disability.
what are causes of early and late neonatal hypocalcemia?
Early - (birth to 4 days) = prematurity, maternal diabetes, perinatal asphyxia, and IUGR
Late - (5 to 10 days) = hyperphosphatemia, hypomagnesaemia, hypoparathyroidism, maternal vit D deficiency, and infantile osteopetrosis.
patient is seen for bowing of the legs.
BW phosphorus level is very low, but the PTH level is normal. Dx
X-linked hypophosphatemic rickets
