Rickets Flashcards
What is rickets?
The failure to mineralize newly formed bone
What are the causes of rickets?
- Lack of vitamin D
2. Lack of phosphate and calcium
Why does rickets occur more in infants?
Because it characteristically manifests during periods of rapid growth which occurs during infancy or adolescent growth spurts
What are the clinical features of rickets?
- Long bone deformities- genu valgus ad genu Varys, windswept appearance
- Delayed closure of the fontanelles
- Rickety rosary(enlarged costochondrial joints)
- Widened metaphyses(ankles and wrists)
- Harrisons sulcus
- Craniotabes
What are the clinical signs of hypocalcaemia?
- Convulsions
- Apneoic attacks
- Laryngospasm
What are the clinical signs of muscle weakness?
- Hypotonia
- Delayed motor milestones
- Prominent abdomen
What specific test would we do in rickets?
- Serum calcium, phosphate, parathyroid hormone, 25OHD
What is on your differential diagnosis if it is not rickets?
- Osteogenesis imperfecta
- Healed rickets
- Metaphyseal dysplasia
What are the pre-disposing factors to getting rickets in young infants?
- Darker skin
- Covering up skin
- Vegetarian diets
- Prolonged breast feeding with no vitamin D supplementation
- Babies born to vitamin d deficient moms
How is vitamin D metabolized?
- It comes in two forms. From the skin(cholecalciferol) and from the diet(ergocalciferol)
- It is then stored in the GIT tract or the muscle or transported in the liver where it becomes 25OH
- It is then transported to the kidney where phosphate or PTH hydroxyulate it to 1,25OH2D
What are the causes of rickets divided into?
- Calcium deficiency rickets
2. Phosphorous deficiency rickets
What are the causes of calcium deficient rickets?
- Decreased vitamin D intake
- diet or sunlight - Decreased Vitamin D absorption
- biliary atresia, coelioc disease - Impaired hydroxylation of vitamin D to 25OH
- Decreased synthesis of 1,25dihydroxy vitamin D
- renal failure - Increased metabolism due to drugs like anti-convulsants
What are the causes of phosphorous deficiency rickets?
- Decreased intake of phosphate
- prematurity - Decreased intestinal absorption
- ingesting aluminum hydroxide - Increased renal losses
- Franconi’s syndrome
