Acute and Non-acute Lower Extremity Pain in the Pediatric Population

Part III

Allison D. Duey-Holtz, MSN, RN, CPNP; Sara L. Collins, MSN, RN, CPNP; Leah B. Hunt, PA-C, MMSc; Polly F. Cromwell, MSN, RN, CPNP


J Pediatr Health Care. 2012;26(5):380-392. 

In This Article



Definition. Rickets is a bone disease caused by disturbances in the metabolism of calcium and phosphate, which results in inadequate mineralization of the bone matrix.


  • Nutritional rickets is caused by a diet deficient in vitamin D; it is found especially among children who have had prolonged breastfeeding without vitamin D supplementation, persons who have eaten vegetarian diets, darker skinned populations, or persons with celiac or hepatic disease

  • Rickets of prematurity: A result of treatment for and risks of prematurity

  • Vitamin D-resistant rickets/familial hypophosphatemic rickets: A normal level of vitamin D is insufficient to achieve normal bone mineralization; genetic link

History of Present Illness.

  • Exclusively breastfed with no vitamin D supplementation

  • Inadequate vitamin D dietary intake

  • Lack of adequate sunlight exposure

  • Winter season

  • Northern latitudes

  • Air pollution/cloud cover

  • Malabsorption

  • Drugs that increase catabolism

  • Liver or kidney disease


  • Enlargement of the skull, that is, frontal bossing or delayed fontanel closure

  • Enlargement of the rib cage

  • Wrist and ankle widening

  • Angular deformities of extremities, that is, genu varum or valgum

  • Muscle weakness

  • Poor growth

  • Delayed tooth eruption

  • Increased susceptibility to infection


  • Large variability with many patients asymptomatic

  • Irritability

  • Gross motor delay

  • Bone pain

  • Seizure due to hypocalcemia

  • Failure to thrive

Diagnostic Tests.

  • Radiograph of lower/upper extremities: widening/cupping of the metaphysis most evident in the epiphyseal ends of the bones

  • Serum alkaline phosphatase, and if elevated, then 25 OH vitamin D, parathormone, calcium, and phosphorus screening

    • Abnormal laboratory results: serum calcium, phosphate, and vitamin D levels are decreased

  • Administer vitamin D

    • < 1 month of age: 1000 International Units (IUs)/day

    • 1–12 month of age: 1000–5000 IUs/day

    • > 12 months of age: > 5000 IUs/day

    • A single high dose of vitamin D or a high dose administered intermittently can be considered if poor compliance is demonstrated (100,000–600,000 IUs over 1 to 5 days)

      • Usual course is 6 to 10 weeks (Wagner & Greer, 2008)


  • Refer the patient to pediatric orthopedics for treatment of lower extremity angular deformity

  • Refer the patient to an endocrinologist as needed for treatment


  • Regular daily intake of vitamin D

    • Infants (0–12 months): 400 IUs

    • Children/adolescents: 600 IUs (Misra, Pacaud, Petryk, Collett-Solberg, & Kappy, 2008)

      • These doses may need to be adjusted based on measured vitamin D levels and/or clinical population (Herring, 2008; Misra et al., 2008; Morrissy & Weinstein, 2006;Wagner & Greer, 2008)