Skeletal fluorosis after prolonged voriconazole therapy

A skeleton in a huff: insights in etiologies of osteosclerosis

A 30-yr-old man developed right lower leg pain and a palpable solid mass. Radiographic imaging revealed a periosteal reaction with an exostotic mass arising from the right distal fibula. Generalized skeletal osteosclerosis with periosteal reaction was discovered on a radiographic skeletal survey. A biopsy of the right fibular mass revealed reactive woven bone. The patient was referred to a metabolic bone disease clinic, where laboratory values were consistent with secondary hyperparathyroidism and increased bone turnover. A DXA bone density scan revealed high bone density, with an L1-4 spine Z-score of +9.3, a left femoral neck Z-score of +8.5, and a total hip Z-score of +6.5. A dental exam revealed generalized gingival inflammation, teeth mobility, generalized horizontal alveolar bone loss and widening of the periodontal ligament space, increased bone density around the teeth, and thickening of the radicular lamina dura. An extensive evaluation was performed, with the result of a single test revealing the diagnosis. The differential diagnoses of osteosclerosis affecting the skeleton, teeth, and oral cavity are discussed.

Skeletal Fluorosis: A Case of Inhalant Abuse Leading to a Diagnosis of Colon Cancer

Skeletal fluorosis is a long-term bone disease that develops when prolonged fluoride toxicity leads to osteosclerosis and bone deformities that result in crippling pain and debility. The disease is endemic to many countries due to environmental or industrial exposures. However, rare cases in the United States have been reported from various causes including heavy toothpaste ingestion, excessive tea consumption, voriconazole use, and inhalant abuse. Here, we present a case of a 41-year-old man who presented for weight loss and severe joint pains due to bony sclerotic lesions found on X-rays. Social history revealed that he had been recreationally inhaling compressed air dusters used for cleaning electronics. Owing to concern for malignancy, he underwent an extensive work-up which led to a diagnosis of colon cancer, but positron emission tomography/computed tomography (PET/CT) and bone biopsy were unexpectedly negative for metastatic bone disease. Further characterization of his lesions by skeletal survey led to a diagnosis of skeletal fluorosis secondary to inhalant abuse. As in this patient, the disease can be difficult for clinicians to recognize as it can be mistaken for various boney diseases such as metastatic cancer. However, once there is clinical suspicion for skeletal fluorosis, various tests to help confirm the diagnosis can include serum and urine fluoride levels, skeletal survey, and bone ash fluoride concentration. Treatment of skeletal fluorosis primarily involves cessation of fluoride exposure, and recovery can take years. Ultimately, further study is required to develop recommendations and guidelines for diagnosis, management, and prognosis of the disease in the United States.