This 8-month-old female presented with wrist swelling. Radiographic imaging of the wrist and knee revealed characteristic signs of rickets, including metaphyseal cupping, fraying and splaying of the long bones.

Laboratory workup showed hypophosphatemia, mild hypocalcemia, and mildly reduced vitamin D levels. Given no signs of nutritional deficiency, the diagnosis of vitamin D-resistant rickets (X-linked hypophosphatemic rickets) was made.

She was treated with 1,25-dihydroxyvitamin D₃ with rapid interval improvement and characteristic signs of healing with new bone formation in the zone of provisional calcification, as evident on knee imaging.

This case was submitted with supervision and input from:

Soni C Chawla, M.D.
Associate Professor
Department of Radiological Sciences
David Geffen School of medicine at UCLA
Olive View-UCLA Medical Center