We report an acute myelitis in a 53-year-old woman that occurred in 7 days after the diagnosis of Th5-6 herpes zoster. Clinical examination revealed hyperhidrosis of left side of her face, neck, arm and upper chest. She also had muscle weakness of her left leg and sensory impairment for light touch and temperature in her chest and legs. Spinal cord MRI demonstrated a longitudinal T2-hyperintense lesion extending from Th1 to 7. In the axial imaging, the lesion dominantly located in the left side gray matter. Hyperhidrosis, weakness and sensory impairment were improved after intravenous therapy with acyclovir and methylprednisolone. VZV (varicella zoster virus) IgG index of the cerebrospinal fluid was high and serological anti aquaporin-4 antibodies were positive at the time of the admission. This case had both characteristics of VZV myelitis and neuromyelitis optica spectrum disorder. Myelitis relapsed 19 months after the first attack. We believe that sympathetic hyper reactivity due to thoracic spinal cord lesion was responsible for the hyperhidrosis in our patient.