Rheumatology Book

http://www.fpnotebook.com/

RicketsAka: Infantile Osteomalacia

Advertisement

  1. See Also
    1. Vitamin D Deficiency
    2. Vitamin D
    3. Osteomalacia
  2. Definition
    1. Vitamin D Deficiency prior to growth plate closure
  3. Epidemiology
    1. Rare now in developed countries
    2. Still, however, occurs in high risk groups
      1. See Vitamin D Deficiency
  4. Risk Factors
    1. Sunlight avoidance
    2. Dark skin
    3. Infant with only Breast Feeding
    4. Calcium deficient diet
    5. Family History (hereditary form)
      1. Short Stature
      2. Alopecia
      3. Poor Dentition
      4. Bow legged
  5. Pathophysiology
    1. Bone fails to mineralize
  6. Types
    1. Nutritional Rickets (Vitamin D Deficient)
      1. Diet deficient in Vitamin D, Calcium, Phosphorus
      2. Inadequate sunlight exposure or dark skin
      3. Malabsorption (see Secondary Rickets below)
    2. Vitamin D Dependent Rickets
      1. Type I: Pseudovitamin D-deficiency Rickets
        1. Autosomal recessive enzymatic gene defect
        2. Renal 25(OH)D3-1-a-hydroxylase deficiency
      2. Type II: Hereditary Vitamin D resistant (rare)
        1. Autosomal recessive defect in Vitamin D receptor
        2. Distinguished by high levels of Calcitriol
    3. Vitamin D Resistant Rickets
      1. Familial Hypophosphatemic Rickets
        1. Most common inherited form
        2. X-linked phosphate regulating gene defect
      2. Hereditary Hypophosphatemic Rickets and Hypocalciuria
    4. Secondary Rickets
      1. Underlying renal disease (Renal Osteodystrophy)
      2. Malabsorption (Celiac Sprue, Cystic Fibrosis, IBD)
      3. Rickets of Prematurity
      4. Malignancy
      5. Medications (due to Hypocalcemia, Hypophosphatemia)
        1. Loop Diuretics
        2. Corticosteroids
        3. Aniconvulsants (Phenytoin)
        4. Aluminum-containing Antacids
  7. Symptoms
    1. General
      1. Irritability
      2. Diaphoresis
    2. Presentation in Infants
      1. Seizure disorder or Tetany secondary to Hypocalcemia
    3. Presentation in Older Children
      1. Failure to Thrive or Short Stature
  8. Signs
    1. Muscular weakness and poor tone
    2. Abdominal distention
    3. Scoliosis
    4. Rachitic Rosary (costochondral beading)
    5. Harrison's Grooves
      1. Flaring of ribs at diaphragm level
      2. Groove forms circumferentially across anterior chest
    6. Contracted pelvis
    7. Pigeon Breast Deformity (Parrot's Bosses)
      1. Sternum projects forward
    8. Frontal bossing of skull with Craniotabes
    9. Knee angulation (Genu Valgum or genu varus)
      1. Especially genu varus in older children
    10. Wrist flaring
    11. Tooth defects
    12. Delayed closure of anterior Fontanel
    13. Osteopenia
  9. Labs: Nutritional Rickets findings
    1. Serum Calcium (ionized or with albumin): Hypocalcemia
    2. Serum phosphate: Hypophosphatemia
    3. Serum Alkaline Phosphatase: >500 IU/dl
    4. Parathyroid Hormone increased
    5. Renal Function tests (Serum Creatinine, urea nitrogen)
    6. Serum Calcidiol decreased
    7. Urine Calcium decreased
    8. Urine pHosphorus increased
  10. Radiology: AP knee or wrist (rapidly growing long bones)
    1. Findings consistent with Rickets
      1. Cupping and fraying at metaphysis/diaphysis
      2. Widened physis
    2. Differential Diagnosis (similar XRay findings)
      1. Congenital Syphilis
      2. Osteogenesis imperfecta
      3. Child Abuse
  11. Management
    1. Natural or artificial ultraviolet light exposure
    2. See Vitamin D Replacement
    3. See Calcium Supplementation (1500 mg daily)
  12. Prevention
    1. Ultraviolet light exposure for infants
      1. Diaper only: 30 minutes exposure per week
      2. Fully clothed: 2 hours per week
    2. Vitamin D Supplementation
      1. Dosing: 400 IU Vitamin D daily
      2. Indication: Breast-fed infants
        1. Mothers not exposed to adequate sunlight
        2. Infants born during cold winters
  13. References
    1. Heird in Behrman (2004) Nelson Pediatrics, p. 186-9
    2. Drezner in Goldman (2004) Cecil Medicine, p. 1555-62

Rickets (C0035579)

Definition (MSH)A condition caused by deficiency of VITAMIN D, especially in infancy and childhood, with disturbance of normal ossification. The disease is marked by bending and distortion of the bones under muscular action, by the formation of nodular enlargements on the ends and sides of the bones, by delayed closure of the fontanels, pain in the muscles, and sweating of the head. Vitamin D and sunlight together with an adequate diet are curative, provided that the parathyroid glands are functioning properly. (Dorland, 27th ed)
Definition (CSP)disorder of calcium and phosphorus metabolism affecting bony structures, due to a variety of defects in vitamin D, calcium, and phosphorous homeostasis, including dietary deficiencies or malabsorption.
ConceptsDisease or Syndrome (T047)
MSHD012279
EnglishHypovitaminosis D, Rickets
Spanishraquitismo
Parent ConceptsVitamin D Deficiency (C0042870), Bone Diseases, Metabolic (C0005944), CALCIUM DISORDER (C0302590), Calcium Metabolism Disorders (C0006705), Non-Neoplastic Bone Disorder (C1334997), Disorder of phosphate, calcium and vitamin D metabolism (C0342627), Disorder with defective osteoid mineralization (C1290193)
SourcesAOD, COSTAR, CSP, CST, DXP, LCH, MSH, NCI, NDFRT, OMIM, SCTSPA, SNOMEDCT
Derived from the NIH UMLS (Unified Medical Language System)



Navigation Tree