How is fluorosis diagnosed and managed?
The lack of rapid laboratory testing available for serum, urine, and bone fluoride concentrations makes the initial diagnosis of fluorosis a clinical one. Imaging studies are generally highly suggestive of fluorosis and can be used to support the diagnosis. A dual energy X-ray absorptiometry scan of the spine, hip, femur, and distal portions of the radii can reveal elevated T-scores consistent with osteosclerosis.14 These findings, in conjunction with bone or joint pain, reduced range of motion, or kyphosis, should prompt clinicians to conduct further testing—even without a confirmed fluoride source. A serum fluoride (reference range, 0.2-3.2 mg/L) and 24-hour urine fluoride (reference range, 0.2-3.2 mg/dL) and creatinine evaluation can be used to diagnose fluorosis. However, a bone biopsy with quantitative bone ash fluoride analysis remains the gold standard for the diagnosis of skeletal fluorosis.16 Laboratory evaluation should also include an assessment of electrolytes, specifically calcium, 25-hydroxyvitamin D, and alkaline phosphatase. The differential diagnosis should include hemoglobinopathies, renal osteodystrophy, Paget disease, hypothyroidism, and skeletal metastases.16
Treatment of fluorosis is largely symptomatic and supportive, with identification and discontinuation of the fluoride source. Patients should be referred to an orthopedist for evaluation and management as needed. Evaluation by an endocrinologist should also be considered because patients may have chronic vitamin D and calcium deficiencies as a result of systemic fluorosis.
Case Conclusion
The patient’s laboratory assessment was notable for the following: alkaline phosphatase, 624 U/L (reference range, 44-147 IU/L); vitamin D, 10 ng/mL (reference range, 20-40 ng/mL); serum fluoride, 0.3 mg/L (reference range, 0.2-3.2 mg/L); urine fluoride, 52 mg/dL (0.2-3.2 mg/dL); and urine creatinine, 1 g/L (reference range, 0.3-3 g/L). Imaging studies noted periosteal bone formation on the lateral epicondyle of the distal right humerus, as well as similar osseous abnormalities in other locations. A bone biopsy was scheduled. The patient was treated with oral vitamin D and educated about the importance of discontinuing the huffing of all hydrocarbons.