Intracerebral Hemorrhage During the Chronic Phase of Eosinophilic Granulomatosis With Polyangiitis: A Case Report Emphasizing Cerebrovascular Vulnerability.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare form of small-vessel vasculitis typically associated with eosinophilia, asthma, and systemic inflammation. Although peripheral neuropathies are relatively common, central nervous system involvement, especially intracerebral hemorrhage during the remission phase of EGPA, is uncommon, and its clinical course and management remain poorly understood. The female patient had been diagnosed with EGPA 6 months earlier based on marked eosinophilia of 16,380/μL, late-onset asthma, and mononeuritis multiplex, fulfilling the 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria. After receiving high-dose corticosteroids (Day-165) and edoxaban for subacute distal deep vein thrombosis (Day-158), her eosinophil count steadily decreased, and she was discharged without hypertension on oral prednisolone 40 mg/day (Day-144). The dose was tapered to 13 mg/day without relapse. On Day 0, she developed acute left putaminal hemorrhage along with previous cerebral microbleeds on susceptibility-weighted imaging (SWI) and an old, small brainstem infarction. Laboratory data showed a normal eosinophil count of 70/μL and normal D-dimer levels. Edoxaban was discontinued, and conservative management was initiated. Follow-up ultrasound on Day 19 confirmed an organized thrombus without progression. She gradually improved with rehabilitation and achieved a modified Rankin Scale score of 1. Although mild sensory disturbance in the right upper and lower extremities persisted, she regained full independence in all activities of daily living and is currently working energetically as a bookstore clerk. She has remained stable for over 3.5 years without anticoagulation or EGPA relapse. This case highlights that, although perhaps overlooked during the remission phase when clinicians may be less careful, intracerebral hemorrhage may occur even during EGPA remission, potentially owing to persistent small-vessel endothelial vulnerability, which may elevate hemorrhagic risk even during clinical remission. The presence of microbleeds and prior infarction may reflect longstanding vascular injury, possibly exacerbated by anticoagulation. Current guidelines do not address this risk, underscoring the need for individualized risk assessment. This case may indicate that brain imaging, including SWI, could be considered prior to initiating anticoagulation therapy in patients with EGPA.