Churg-Strauss syndrome with concomitant occurrence of ischemic stroke and relapsing purpura

A 77-year-old woman suffering from chronic bronchial asthma and chronic atrial fibrillation who had had a previous ischemic stroke presented to our emergency unit with gait disturbance. She had new-onset truncal ataxia, right hemiparesis, and right sensory disturbance related to the previous stroke. Her lower legs were slightly swollen and had a reddened appearance. Her medical history included mitral valve replacement because of severe mitral valve regurgitation. Her white blood cell count was 8600/μL, mainly consisting of eosinophils (4480/μL; 52.1%). Serum nonspecific immunoglobulin E was elevated to 1600 IU/mL (normal range <170 IU/mL). She was taking warfarin for secondary stroke prevention, and on admission her prothrombin time international normalized ratio was 3.06. Diffusion-weighted magnetic resonance imaging revealed a fresh infarct in the right cerebellum. No stenosis or occlusion was shown in the cervicocephalic arteries on magnetic resonance angiography or carotid ultrasound. No emboligenic diseases, except for atrial fibrillation, were identified. On day 3, an extensive itchy, purpuric rash appeared on her lower limbs. The rash remitted and recurred spontaneously for several weeks. A skin biopsy specimen of the purpuric lesions revealed massive eosinophilic infiltration of the dermis and eosinophilic vasculitis involving small vessels. We diagnosed the patient with Churg-Strauss syndrome (CSS). Skin lesions and eosinophilia disappeared after oral corticosteroid therapy. In this case, cerebellar infarction occurred with purpuric rash despite well-controlled anticoagulation. Patients with CSS may suffer from ischemic stroke when the condition of CSS deteriorates.