A Case of Urinary Tract Infection Resulting From Voiding Dysfunction Caused by Sacral Herpes Zoster Involving the Left Buttock.

Herpes zoster-associated voiding dysfunction is an uncommon complication but may occur when the sacral dermatomes are involved. In immunocompromised patients, including kidney transplant recipients receiving immunosuppressive therapy, urinary retention may predispose patients to secondary urinary tract infections such as pyelonephritis. Prompt recognition and appropriate management are therefore essential. We report the case of a woman with a history of living-donor kidney transplantation who developed urinary retention and pyelonephritis following herpes zoster involving the buttock. She had been receiving maintenance immunosuppressive therapy with methylprednisolone, mizoribine, and cyclosporine. After the diagnosis of herpes zoster, antiviral therapy was initiated. Several days later, she developed dysuria caused by urinary retention, which was successfully managed with corticosteroid therapy and temporary urinary catheterization. However, she subsequently developed fever and was diagnosed with acute pyelonephritis on hospital day 7. Intravenous antibiotic therapy resulted in gradual clinical improvement, and inflammatory markers and urinary findings normalized by hospital day 15. This case highlights that sacral herpes zoster can cause neurogenic bladder dysfunction, resulting in urinary retention and subsequent pyelonephritis, particularly in immunocompromised patients. Careful monitoring of urinary symptoms and early intervention may help prevent serious infectious complications in this high-risk population.