Difference between revisions of "Rickets"
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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) | ||
==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 16:45, 29 September 2019
Contents
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)
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)