Case Presentation: A 70-year-old man with a remote history of pulmonary tuberculosis presented with several days of abdominal pain, distention, constipation, and difficulty urinating. One week earlier, he developed a painful, erythematous vesicular rash on his abdomen and lower back, diagnosed as shingles involving the sacral dermatomes. He was treated with valacyclovir, nitrofurantoin, and gabapentin. On return to the hospital, his rash had improved, but he reported worsening pain and inability to void. Examination revealed crusted vesicular lesions over the sacral region and a distended, tender abdomen. Laboratory tests showed significantly elevated creatinine, normal WBC, and normal urinalysis and urine culture. CT imaging demonstrated marked bladder distention and bilateral hydroureteronephrosis. An indwelling catheter drained over 5 liters of urine, resolving his acute kidney injury. He failed a voiding trial and was discharged with a catheter and urology follow-up.
Discussion: Herpes zoster (shingles) results from reactivation of varicella zoster virus, which remains latent in sensory ganglia after primary infection. It typically presents as a painful, unilateral vesicular rash in a dermatomal pattern, often preceded by prodromal symptoms such as malaise, headache, and localized skin sensations. When the sacral dermatomes (S2–S4) are involved, the virus can disrupt bladder control, leading to acute urinary retention, incontinence, or detrusor paralysis due to impaired parasympathetic function. The incidence of shingles rises with age and immunosuppression, affecting about one in three people in their lifetime and causing roughly one million cases annually in the United States. Most cases of zoster related bladder dysfunction are transient, with recovery usually within weeks to a few months, but early recognition and supportive management including catheterization and antiviral therapy are important to prevent complications.
Conclusions: Urinary retention is a rare complication of herpes zoster infection, but the risk rises substantially when the lumbosacral dermatomes are involved. Most cases are transient and resolve within weeks to a few months with supportive management, such as catheterization and early treatment. Clinicians should maintain a high index of suspicion for urinary retention in patients with sacral herpes zoster, as this presentation is uncommon, but clinically significant and can impact quality of life.