Rituximab in the Treatment of Subarachnoid Hemorrhage and Widespread Bleeding in Microscopic Polyangiitis : A Case Report.

Microscopic polyangiitis (MPA) is a rare autoimmune disorder characterized by small-vessel vasculitis and the presence of anti-neutrophil cytoplasmic antibody (ANCA). Typically, MPA primarily affects the respiratory system, kidneys, and skin, with infrequent involvement of the nervous system, resulting in neuropathy. However, the occurrence of subarachnoid hemorrhage (SAH) in MPA is exceedingly rare, especially when it is accompanied by hemorrhagic events in multiple organs. This case report details the clinical presentation of a 61-year-old male patient diagnosed with MPA who experienced an exceptionally uncommon occurrence of SAH, coupled with extensive bleeding manifestations including epistaxis, skin purpura, and gastrointestinal bleeding. Notably, the patient's symptoms exhibited potential improvement following a treatment regimen consisting of rituximab and glucocorticoids. This case emphasizes the critical importance of promptly recognizing and comprehensively managing rare complications in MPA patients to optimize clinical outcomes.