Abstract
Hypereosinophilic syndrome (HES) is characterized by the presense of hypereosinophilia with evidence of target organ damage. We report a patient diagnosed with eosinophilic cystitis and HES. A 7 year old boy had hematuria, dysuria, and increased urinary frequency for 1 day. Laboratory examinations revealed hypereosinophilia (eosinophils, $2,058/{\mu}L$), hematuria, and proteinuria. Abdominal sonography revealed diffuse and severe wall thickening of the bladder. The patient was treated initially with antibiotics. However, his symptoms did not improve after 7 days. A computed tomography scan demonstrated severe wall thickening of the bladder and the hypereosinophilia persisted (eosinophils, $2,985/{\mu}L$). The patient complained of chest discomfort, dyspnea, epigastric pain, and vomiting on hospital day 10. Parasitic, allergic, malignancy, rheumatologic, and immune workups revealed no abnormal findings. Chest X-rays, electrocardiography, and a pulmonary function test were normal; however, the hypereosinophilia was aggravated (eosinophils, $3,934/{\mu}L$). Oral deflazacort was administered. A cystoscopic biopsy showed chronic inflammation with eosinophilic infiltration. The patient's respiratory, gastrointestinal, and urinary symptoms improved after 6 days of steroids, and he was discharged. The eosinophil count decreased dramatically ($182/{\mu}L$). The hypereosinophilia waxed and waned for 7 months, and the oral steroids were tapered and stopped. This case describes a patient diagnosed with eosinophilic cystitis and HES.
