Rickets: Difference between revisions
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==Background== | ==Background== | ||
* | *Bone disorder characterized by soft, weak, and deformed bones | ||
* | *Predominantly caused by [[Vitamin D deficiency]] or impaired vitamin D metabolism, but can also be due to [[hypocalcemia]] | ||
* | *More common in areas with high rates of early childhood malnutrition/starvation | ||
*The predominant cause is a [[Vitamin D deficiency]], but also inadequate calcium and impaired metabolism of vitamin D may also lead to rickets | |||
===Metabolism and Physiology of Vitamin D=== | |||
*Gained from diet, supplements, or sunlight exposure | |||
**Fortified foods (mainstay), supplements, fatty fish, egg yolks, fish liver oil, and some mushrooms | |||
**Synthesis of vitamin D occurs in the skin through exposure to ultraviolet B radiation from sunlight | |||
*Hydroxylated in liver→ 25-hydroxyvitamin D, which is further hydroxylated in kidney or extrarenally→ 1,25-dihydroxyvitamin D (active form) | |||
**Second hydroxylation regulated by PTH, serum calcium, and phosphorus levels | |||
*Vitamin D acts to: | |||
**Stimulate intestinal calcium absorption | |||
**Maintain adequate phosphate levels for bone development | |||
**Regulate cell growth proliferation and apoptosis | |||
**Modulate immune function and inflammation reduction | |||
===Etiology of Vitamin D Deficiency=== | |||
*Inadequate intake | |||
**Maternal [[vitamin D deficiency]]: in utero, 25-hydroxyvitamin D passes through the placenta to the infant | |||
**Exclusive breastfed infants without vitamin D supplementation | **Exclusive breastfed infants without vitamin D supplementation | ||
* | *Inadequate sunlight exposure, dark skin pigmentation | ||
** | *Impaired vitamin D absorption | ||
*** | **[[Crohn's disease]], [[cystic fibrosis]] | ||
*Impairment in conversion of vitamin D into active metabolites | |||
**[[Renal Failure]], [[Liver failure]] | |||
===Types of [[Rickets]]=== | |||
*Hereditary rickets | |||
**Kidneys unable to retain phosphate | |||
*Nutritional rickets | |||
*Vitamin D Resistant Rickets | |||
*Vitamin D Dependant Rickets | |||
*Congenital Rickets | |||
==Clinical Features== | ==Clinical Features== | ||
*Peak incidence between 3 and 18 months of age | *Peak incidence between 3 and 18 months of age | ||
*Enlarged and soft skull ( | *Bony pain | ||
*Generalized muscle [[weakness]] | |||
*[[Hypocalcemia]] | |||
* | *[[failure to thrive (peds)|Growth disturbance]] | ||
*Enlarged and soft skull (craniotabes), long bones, joints of rib cage ("rickety rosary") | |||
*Metaphyseal hyperplasia (double malleoli sign, widening of wrist) | |||
*Bowed legs in toddlers (genu varum), knock-knees in older children (genu valgum) | |||
*[[Dental problems]] | |||
* | |||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
*[[Hypocalcemia]] | |||
*[[Hyperparathyroidism]] | |||
*[[Hypophosphatemia]] | |||
*Malignancy | |||
*[[Nonaccidental trauma]] (if evidence of multiple acute or healing fractures) | |||
{{template:vitamin deficiencies DDX}} | |||
==Evaluation== | ==Evaluation== | ||
*Assess for fractures, if indicated | |||
*BMP, Mg/Phos, serum calcium | |||
===Serum 25-hydroxyvitamin D=== | |||
''Vitamin D assessed by measuring this precursor to hormonally active 1,25-dihydroxyvitamin D'' | |||
*Normal range: 75-250 nmol/L | |||
*Insufficiency: 25-75 nmol/L | |||
*Deficiency: <25 nmol/L | |||
==Management== | ==Management== | ||
* | *Treat complications (e.g. [[hypocalcemia]], [[fractures]], [[analgesia|bone pain]]) | ||
** | *Supplemental vitamin D | ||
**Initial high-dosage treatment phase: 1,000 IU cholecalciferol per 10 nmol/L required serum increase given daily for 2-3 months | |||
**Maintenance: 400 IU daily | |||
***Double dosage for premature infants, infants/children with dark pigmentation, children with limited sun exposure, and obese patients | |||
**Some populations may require higher dosing (i.e. parathyroid disease, chronic liver disease, renal failure, and malabsorption disorders) | |||
==Disposition== | ==Disposition== | ||
==See Also== | ==See Also== | ||
*[[Vitamin D deficiency]] | |||
==External Links== | ==External Links== | ||
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==References== | ==References== | ||
<references/> | <references/> | ||
[[Category:Orthopedics]] [[Category:Pediatrics]] [[Category:FEN]] |
Latest revision as of 19:13, 23 February 2021
Background
- Bone disorder characterized by soft, weak, and deformed bones
- Predominantly caused by Vitamin D deficiency or impaired vitamin D metabolism, but can also be due to hypocalcemia
- More common in areas with high rates of early childhood malnutrition/starvation
- The predominant cause is a Vitamin D deficiency, but also inadequate calcium and impaired metabolism of vitamin D may also lead to rickets
Metabolism and Physiology of Vitamin D
- Gained from diet, supplements, or sunlight exposure
- Fortified foods (mainstay), supplements, fatty fish, egg yolks, fish liver oil, and some mushrooms
- Synthesis of vitamin D occurs in the skin through exposure to ultraviolet B radiation from sunlight
- Hydroxylated in liver→ 25-hydroxyvitamin D, which is further hydroxylated in kidney or extrarenally→ 1,25-dihydroxyvitamin D (active form)
- Second hydroxylation regulated by PTH, serum calcium, and phosphorus levels
- Vitamin D acts to:
- Stimulate intestinal calcium absorption
- Maintain adequate phosphate levels for bone development
- Regulate cell growth proliferation and apoptosis
- Modulate immune function and inflammation reduction
Etiology of Vitamin D Deficiency
- Inadequate intake
- Maternal vitamin D deficiency: in utero, 25-hydroxyvitamin D passes through the placenta to the infant
- Exclusive breastfed infants without vitamin D supplementation
- Inadequate sunlight exposure, dark skin pigmentation
- Impaired vitamin D absorption
- Impairment in conversion of vitamin D into active metabolites
Types of Rickets
- Hereditary rickets
- Kidneys unable to retain phosphate
- Nutritional rickets
- Vitamin D Resistant Rickets
- Vitamin D Dependant Rickets
- Congenital Rickets
Clinical Features
- Peak incidence between 3 and 18 months of age
- Bony pain
- Generalized muscle weakness
- Hypocalcemia
- Growth disturbance
- Enlarged and soft skull (craniotabes), long bones, joints of rib cage ("rickety rosary")
- Metaphyseal hyperplasia (double malleoli sign, widening of wrist)
- Bowed legs in toddlers (genu varum), knock-knees in older children (genu valgum)
- Dental problems
Differential Diagnosis
- Hypocalcemia
- Hyperparathyroidism
- Hypophosphatemia
- Malignancy
- Nonaccidental trauma (if evidence of multiple acute or healing fractures)
Vitamin deficiencies
- Vitamin A deficiency
- Vitamin B deficiencies
- Vitamin B1 deficiency (Thiamine)
- Vitamin B3 deficiency (Pellagra)
- Vitamin B9 deficiency (Folate)
- Vitamin B7 deficiency (Biotin)
- Vitamin B12 deficiency
- Vitamin C deficiency (Scurvy)
- Vitamin D deficiency (Rickets)
- Vitamin E deficiency
- Vitamin K deficiency
- Zinc deficiency
Evaluation
- Assess for fractures, if indicated
- BMP, Mg/Phos, serum calcium
Serum 25-hydroxyvitamin D
Vitamin D assessed by measuring this precursor to hormonally active 1,25-dihydroxyvitamin D
- Normal range: 75-250 nmol/L
- Insufficiency: 25-75 nmol/L
- Deficiency: <25 nmol/L
Management
- Treat complications (e.g. hypocalcemia, fractures, bone pain)
- Supplemental vitamin D
- Initial high-dosage treatment phase: 1,000 IU cholecalciferol per 10 nmol/L required serum increase given daily for 2-3 months
- Maintenance: 400 IU daily
- Double dosage for premature infants, infants/children with dark pigmentation, children with limited sun exposure, and obese patients
- Some populations may require higher dosing (i.e. parathyroid disease, chronic liver disease, renal failure, and malabsorption disorders)