Rickets: Difference between revisions

 
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==Background==
==Background==
*Preventable condition in infants and children that is attributed to [[Vitamin D deficiency]] and [[Hypocalcemia]]
*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:
*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  
*Inadequate sunlight exposure, dark skin pigmentation
**Maternal [[Vitamin D deficiency]]
*Impaired vitamin D absorption
***In utero, 25-hydroxyvitamin D passes through the placenta to the infant
**[[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 (Craniotabes)
*Bony pain
*Enlarged joints of long bones
*Generalized muscle [[weakness]]
*Enlarged joints of the rib cage (aka "rickety rosary"
*[[Hypocalcemia]]
*Double malleoli sign due to metaphyseal hyperplasia
*[[failure to thrive (peds)|Growth disturbance]]
*Widening of wrist due to metaphyseal cartilage hyperplasia
*Enlarged and soft skull (craniotabes), long bones, joints of rib cage ("rickety rosary")
*Curvature of the spine and femurs
*Metaphyseal hyperplasia (double malleoli sign, widening of wrist)
**Bowed legs in toddlers (Genu varum)
*Bowed legs in toddlers (genu varum), knock-knees in older children (genu valgum)
**Knock-knees in older children (Genu valgum)
*[[Dental problems]]
*Generalized muscle weakness
*Bony pain or tenderness
*Dental problems
*Growth disturbance
*Hypocalcemia
**Tetany


==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==
*Prevention key:
*Treat complications (e.g. [[hypocalcemia]], [[fractures]], [[analgesia|bone pain]])
**For healthy infants, children, and adolescents recommend a vitamin D intake of at least 400 IU/day
*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

Vitamin deficiencies

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