Case Report: Herpes zoster-associated abdominal wall bulge with ipsilateral muscle atrophy

Herpes zoster (HZ) is the reactivation of the varicella-zoster virus and usually causes unilateral dermatomal vesicles; deep tissue involvement is uncommon. We report a 76-year-old man who, 12 days after classic right-flank HZ in the T11 dermatome, developed a painless right-sided abdominal bulge. Examination found a soft, non-pitting swelling. Computed tomography demonstrated ipsilateral thinning of the abdominal wall muscles without evidence of a fascial defect, true hernia, or mass, consistent with zoster-related segmental motor neuropathy presenting as an abdominal pseudohernia. He was managed conservatively with reassurance; no surgery was required. This case highlights a rare neuromuscular complication of HZ and supports the use of imaging in unexplained post-zoster abdominal swelling.