RESUMEN
BACKGROUND: Eosinophilic cystitis is a rare inflammatory disorder characterized by eosinophilic infiltration of all layers of the urinary bladder wall. Due to lack of consensus and potential for side effect from various therapeutic options, treatment of the disease is often challenging. CASE PRESENTATION: A 64-year old woman with hypertensive nephropathy resulting in stage III chronic kidney disease, obstructive sleep apnea, and obstructive lung disease presented with a 4 month history of dysuria, urgency, frequency, and persistent hematuria. Based on eosinophilic infiltration on bladder wall biopsy in the absence of any evidence of infection, malignancy, or immune disorder, she was diagnosed with eosinophilic cystitis. Despite multiple medication regimens, her symptoms persisted, requiring high-dose prednisone with steroid-related side effects. After four months, she was started on cyclosporine, which led to symptomatic improvement and reduction in prednisone dosage. At that time, repeat urine cytology and cystoscopy did not reveal friable tissues or eosinophiluria. CONCLUSION: This case illustrates the utility of using cyclosporine to treat eosinophilic cystitis in adult patient with multiple comorbid conditions.