Post-herpetic Abdominal Pseudohernia With Underrecognized Characteristics of Male Predominance and Co-occurring Fatal Visceral Herniation: A Case Report and a Literature Review.

Post-herpetic abdominal pseudohernia (PHAP) is a rare complication associated with herpes zoster (HZ), characterized by transient paresis of the myotome ipsilateral to the affected segmental nerves. Clinically, it manifests as asymptomatic laxity and protrusion of the abdominal musculature, mimicking abdominal wall herniation. While the varicella-zoster virus (VZV) primarily affects the sensory nervous system, the incidence and prognosis of motor involvement remain poorly estimated. Despite PHAP's self-limiting nature with a favorable prognosis in most cases, the disease requires a careful differential diagnosis to exclude a variety of structural and neurological impairments that may potentially complicate clinical assessment. In this report, we describe a 68-year-old male patient with PHAP who developed segmental abdominal paresis two weeks after completing antiviral therapy for an HZ rash on the corresponding unilateral abdominal wall. The segmental hemiparesis was managed successfully with a combined administration of oral pregabalin, a voltage-gated calcium channel inhibitor, and vitamin B12, leading to significant improvement in impaired motor function within two months. We further discuss the current understanding of PHAP with an updated literature review of 94 cases thus far reported, emphasizing underrecognized differential diagnoses and treatment necessity that may contribute to prognostic benefits.