A rare case of voriconazole-induced vertebral periostitis in a patient with invasive aspergillus spondylodiscitis

The author illustrates the first ever reported case of voriconazole-induced periostitis of vertebral body. A 66-year-old immunocompetent male patient was diagnosed with multilevel invasive aspergillus spondylodiscitis of dorsal spine and was put on long-term voriconazole therapy for the same. Initially, the patient showed a good response to treatment but later on paradoxically the patient started to deteriorate symptomatically as well as radiologically. Differential diagnosis of misdiagnosis or co-infection with an another mold, inadequate voriconazole blood levels, voriconazole-induced periostitis were thought. After a detailed radiological and serological investigation, the patient was diagnosed with voriconazole-induced vertebral periostitis. Based on thorough literature review, discontinuation of voriconazole therapy was opted as treatment. Clinically, the patient started improving within four weeks of cessation of therapy and was symptom-free by the end of four months. Hence, to conclude, clinicians and spine surgeons should be aware of the fact that long-term voriconazole treatment of invasive aspergillosis can be complicated by skeletal fluorosis and painful periostitis. Once the symptoms of periostitis develop, investigations such as skeletal imaging and measurement of serum fluoride levels should be performed and if periostitis deformans is confirmed, reducing the dose or ceasing voriconazole should be considered.