Abstract
We report a rare case of monoparesis due to herpes zoster infection in an 83-year-old female. Weakness in the woman's upper limb started soon after the appearance of a vesiculo-papular rash over the left shoulder area extending down into the arm. Investigations were essentially normal apart from herpes zoster DNA being detected in PCR testing of a swab taken from the skin lesions. Imaging studies ruled out other possible causes of weakness like stroke and brachial plexus injury. The patient was commenced on antiviral treatment, which led to gradual improvement in the weakness. This is one of the lesser-known complications of herpes zoster, which can have a significant impact on quality of life. Also called zoster-associated limb paresis (ZALP), it can affect 0.5-5% of herpes zoster cases.