1000 - Beyond the Rash: Herpes Zoster as a Cause of Brachial Plexopathy and Motor Deficit: A Case Report

Case Diagnosis: Upper trunk brachial plexopathy secondary to herpes zoster infection

Case Description:

A 69-year-old male developed sudden-onset left upper extremity pain and weakness, followed by a vesicular rash in the C5-C6 dermatomes. Initial evaluation led to referral for suspected rotator cuff pathology. Though treated with acyclovir for HZ, brachial plexopathy was not recognized. Referral to Physical Medicine and Rehabilitation (PM&R) was delayed, and oral prednisone was prescribed for presumed dermatitis rather than neurologic involvement.

Discussions:

This case illustrates the diagnostic challenge of HZ-related brachial plexopathy, particularly when presenting like common orthopedic conditions. In older adults, viral plexopathies may be overlooked in cases of acute shoulder pain and weakness. Misdiagnosis can delay rehabilitation and lead to unnecessary surgical evaluation. Greater awareness of this presentation can facilitate earlier recognition and targeted management.

Conclusions:

Clinicians should include HZ-associated brachial plexopathy in the differential diagnosis of acute shoulder pain and weakness in older adults with dermatomal rash. Early identification is key to preventing delays in rehabilitation and inappropriate interventions.