Rickets Flashcards
Give 4 causes of rickets
Nutritional deficiency
Intestinal malabsorption
Increased metabolism of 1,25-dihydroxycholecalciferol
Decreased production of 1,25-dihydroxycholecalciferol
Decreased production of 25-hydroxycholecalciferol
3 risk factors for nutritional deficiency
Vit D deficient diet -Extensive breast feeding into late infancy
Low exposure to light
Dark skin
Low maternal Vit D
2 causes of intestinal malabsorption
Cystic fibrosis
Coeliac disease
Previous bowel resection
2 types of drugs which cause Vit D deficiency?
Phenytoin
Carbamazepine
Phenobarbitol
What feature might you see on a chest x-ray in someone with rickets?
Rachitic rosary
3 features you might see on an x-ray of a wrist in some one with rickets?
Widening (Splaying) of the metaphysis
Fraying of the metaphysis
Cupping of the metaphysis
Looser Zones (pseudofractures)
Features of rickets?
Moderate
• Radiological or biochemical changes
Severe
• Poor growth/short stature
• Misery
• Rachitic rosary –> Palpable costochondral junction
• Craniotabes –> Ping-pong ball sensation elicited by pressing firmly over occipital or posterior parietal bones
• Widened knee and ankles (esp in walking infants)
• Harrison’s sulcus –> Horizontal depression on lower chest corresponding to attachment of softened ribs with diaphragm
• Bow-legged –> Genu vara/ Genu valga
• Delayed closure of anterior fontanelle
• Delayed dentition
• Pseudoseizures
• Motor delay
Severe and life threatening • Cardiomyopathy • Hypocalcaemic convulsions (carbapedal spasms) • Hypotonia • Seizures • Respiratory distress
Investigations
ALP level high
25-hydroxyvitamin D level low (if high, suspect renal problem)
PTH level high
Calcium and phosphate levels low
Management
Based on 25(OH)D levels:
Usually diet modification
If not, Vit D supplements (cholecalciferol) +/- calcium
If hypocalcaemia –> Vit D + IV calcium
