P47 | Evening fever, hopefully a diagnosis

Preface: Hypertrophic pachymeningitis (HP) is a rare disease causing thickening of the dura mater with multiple etiologies (inflammatory, infectious, autoimmune).Case: A 77-year-old Caucasian male has been experiencing evening fevers, rhinosinusitis, and a cough for 2 months; He has type II diabetes mellitus, myelodysplastic syndrome, and prostate hypertrophy. Previous outpatient and instrumental evaluations concluded with rhinosinusitis, which was treated with antibiotics without benefit. Admitted, he was investigated for fever of unknown origin with microbiological tests (positive Quantiferon, rhinovirus), hematochemical tests (MGUS IgG/k), autoimmunity (negative ANCA), metal search (negative), PET-CT (bone marrow uptake), BOM (bilineage dysplasia), and maxillofacial CT (chronic rhinosinusitis). Clinical worsening during hospitalization (gait instability, headache, hearing loss, and visual impairment) necessitated a spinal tap (non-significant, BK negative) and an MRI of the brain with contrast, which revealed intralabyrinthine hemorrhage and a picture compatible with PI, either from ANCA-negative vasculitis (ENT biopsy not performed due to macroscopic integrity) or idiopathic (dural biopsy needed). The patient was treated with high-dose methylprednisolone with benefit, then with decreasing doses of oral prednisone, and with TB prophylaxis.Conclusions: PI represents a clinical challenge also due to the difficulty of obtaining a biopsy: A multidisciplinary approach is necessary to formulate a diagnostic hypothesis and initiate therapy promptly.