Difference between revisions of "Rickets"

(Clinical Features)
 
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==Background==
 
==Background==
*Preventable condition in infants and children that is attributed to [[Vitamin D deficiency]]
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*Bone disorder characterized by soft, weak, and deformed bones
*Extreme deficiency leading to decrease bone mineralization in children, with or without hypocalcemia
+
*Predominantly caused by [[Vitamin D deficiency]] or impaired vitamin D metabolism, but can also be due to [[hypocalcemia]]
*Risk factors for [[Vitamin D deficiency]] in infants include:
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*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  
**Dark skin pigmentation  
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*Inadequate sunlight exposure, dark skin pigmentation
**Maternal [[Vitamin D deficiency]]
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*Impaired vitamin D absorption
***In utero, 25-hydroxyvitamin D passes through the placenta to the infant
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**[[Crohn's disease]], [[cystic fibrosis]]
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*Impairment in conversion of vitamin D into active metabolites
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**[[Renal Failure]], [[Liver failure]]
 +
 
 +
===Types of [[Rickets]]===
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*Hereditary rickets
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**Kidneys unable to retain phosphate
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*Nutritional rickets
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*Vitamin D Resistant Rickets
 +
*Vitamin D Dependant Rickets
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*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 skull, joints of long bones, and rib cage
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*Bony pain
*Curvature of the spine and femurs
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*Generalized muscle [[weakness]]
*Generalized muscle weakness
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*[[Hypocalcemia]]
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*[[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==
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*[[Hypocalcemia]]
 +
*[[Hyperparathyroidism]]
 +
*[[Hypophosphatemia]]
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*Malignancy
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*[[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/>
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 +
[[Category:Orthopedics]] [[Category:Pediatrics]] [[Category:FEN]]

Latest revision as of 16:45, 29 September 2019

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

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)

Disposition

See Also

External Links

References