From the Guidelines
The diagnostic workup for Rickets should include a comprehensive assessment of clinical features, laboratory tests, and imaging studies, with a focus on radiographic studies of the wrists, knees, and ankles to identify characteristic findings such as cupping, fraying, and widening of the growth plates, as recommended by recent clinical practice guidelines 1. The workup should begin with a thorough history and physical examination, looking for signs like bowed legs, delayed fontanelle closure, rachitic rosary, and growth delays. Laboratory evaluation should include serum calcium, phosphorus, alkaline phosphatase, 25-hydroxyvitamin D, parathyroid hormone, and urinary calcium and phosphorus levels. Some key points to consider in the diagnostic workup include:
- Clinical evaluation, including measurement of intercondylar and/or intermalleolar distance, in addition to height and growth velocity, as well as assessment of limb deformity and joint alignment 1
- Radiographic assessment, including evaluation of the wrists, knees, and ankles, to identify characteristic findings such as cupping, fraying, and widening of the growth plates 1
- Additional tests, such as a complete blood count, renal function tests, and liver function tests, to rule out other causes of rickets
- Genetic testing, in cases of suspected genetic rickets, to distinguish between nutritional rickets (vitamin D deficiency), hypophosphatemic rickets, and other metabolic bone disorders 1 Early diagnosis is crucial, as treatment varies based on the underlying cause, with nutritional rickets typically responding well to vitamin D supplementation, while other forms may require specific therapies targeting the underlying metabolic defect.
From the FDA Drug Label
Blood calcium and phosphorus determinations must be made every 2 weeks or more frequently if necessary. X-rays of the bones should be taken every month until condition is corrected and stabilized. The diagnostic workup for Rickets includes:
- Blood tests: to determine calcium and phosphorus levels, which should be done every 2 weeks or more frequently if necessary 2
- X-rays: of the bones, which should be taken every month until the condition is corrected and stabilized 2
From the Research
Diagnostic Workup for Rickets
The diagnostic workup for Rickets, a disease caused by Vitamin D deficiency, involves a combination of clinical symptoms, radiological findings, and biochemical analyses.
- Clinical symptoms include thickened wrists and ankles, growth failure, bone pain, muscle weakness, waddling gait, and leg bowing 3, 4.
- Radiological findings on X-rays of the wrist or knee show metaphyseal fraying and widening of growth plates 3, 5.
- Biochemical analyses include elevated serum levels of alkaline phosphatase, normal or decreased serum calcium and inorganic phosphate concentrations, and decreased serum 25-hydroxyvitamin D (25(OH)D) levels 3, 6, 7.
Biochemical Tests
Biochemical tests are essential in the diagnostic workup of Rickets.
- Serum 25(OH)D levels can be used to diagnose vitamin D deficiency, with a cutoff value of 90.70 nmol/L (sensitivity 68.49%, specificity 72.73%) 7.
- Other biochemical tests include serum calcium, phosphorus, and alkaline phosphatase levels, which can be abnormal in patients with Rickets 3, 6.
Radiological Findings
Radiological findings are also crucial in the diagnosis of Rickets.
- X-rays of the wrist or knee can show metaphyseal fraying and widening of growth plates, which are characteristic of Rickets 3, 5.
- Radiographs can also show other abnormalities, such as bowing deformities of the legs and widening of joints 4.
Genetic Tests
Genetic tests may be necessary to diagnose heritable types of Rickets, which are caused by mutations in genes involved in vitamin D metabolism or action, renal phosphate reabsorption, or synthesis or degradation of the phosphaturic hormone fibroblast growth factor 23 (FGF23) 3, 4.