Patients with diabetes mellitus (DM) are at increased risk of infections, with the urinary tract being the most frequent infection site. Incomplete bladder emptying, frequent urination and abdominal distension are typical symptoms of urinary tract infections (UTIs). A 68-year-old female with a long history of poorly controlled type 2 DM (T2DM) visited our hospital complaining of urinary retention, which was initially diagnosed as cystitis by another doctor. The urologist at our hospital identified a skin rash extending from the left hip to her genital area. A dermatologist was consulted. She was clinically diagnosed with herpes zoster (HZ) involving the left sacral dermatome area. As Elsberg syndrome (ES) was suspected, a lumbar puncture was performed, revealing aseptic meningitis associated with varicella zoster virus (VZV) infection. Intravenous acyclovir with urinary catheterization in combination with methylprednisolone pulse therapy resulted in a good clinical course. HZ very uncommonly involves sacral dermatomes, but it can develop in patients with prolonged poorly controlled DM. Furthermore, early diagnosis can be difficult when patients have diabetic peripheral neuropathy, which may mask symptoms related to skin lesions. Because this disease is potentially severe, detailed examination is important for clinicians managing patients with DM who have complaints indicative of urinary tract disorders.