[Updates on rickets and osteomalacia: guidelines for diagnosis of rickets and osteomalacia]

Rickets and osteomalacia are disorders of calcification characterized by defects of bone and cartilage mineralization during growth, and bone mineralization in adults, respectively. The specific x-ray findings including a cupping, flaring, and fraying of metaphysis and the elevation of the level of serum alkaline phosphatase are essential for the diagnosis of rickets. In addition, hypophosphatemia, hypocalcemia, and some symptoms including born deformity, spinal curvature, craniotabes, enlargement of the anterior fontanel, rachitic rosary, and joint swelling are also important. Clinicians need to consider the different normal ranges of the levels of serum alkaline phosphatase and phosphate depending on their patient's age when they diagnose their childhood patients. In contrast, the radiographic diagnosis of osteomalacia is difficult. The hypophosphatemia or hypocalcemia and the elevation of serum bone alkaline phosphatase are essential for the diagnosis of osteomalacia. Moreover, some clinical features including muscle weakness and bone pain, the decrease of bone density, and the finding of multiple uptake in bone scintigraphy or of the pseudofracture in bone x-ray study are also important. It is very useful for the differential diagnosis to measure the serum levels of 25-hydroxy vitamin D and fibroblast growth factor 23.