Part of “CHAPTER 66 – RARE DISORDERS OF SKELETAL FORMATION AND HOMEOSTASIS“

Chronic ingestion or inhalation of large amounts of fluoride causes fluorosis.48 In the United States, prolonged administration of sodium fluoride as a therapy for postmenopausal osteoporosis represents an increasingly unlikely cause. Mottled discoloration of the teeth, diffuse bone pain reflecting an underlying osteomalacia, and a plantar fascia syndrome characterized by painful feet may be presenting features. Biochemical diagnosis by assay of the fluoride ion in 24-hour urine collections can be obtained through commercial laboratories. Early radiographic signs include irregularity at the point of attachment of muscles to the iliac spine and calcification of ligaments in the pelvis, vertebrae, and interosseous membranes.5 Later, generalized osteosclerosis can occur. Histopathologic studies may reveal osteomalacia (fluoride stimulates osteoid synthesis by osteoblasts, yet mineral deposition is impaired). Treatment consists of protection from fluoride exposure and, if osteomalacia is present, calcium supplementation to mineralize the excess osteoid (see Chap. 63 and Chap. 131).