# Localized Bullous Pemphigoid Triggered by Surgical Trauma: A Case Highlighting the Koebner Phenomenon

## TL;DR

An elderly woman developed bullous pemphigoid along a surgical scar, showing how skin trauma can trigger this autoimmune skin condition.

## Contribution

This case highlights the Koebner phenomenon in bullous pemphigoid triggered by surgical trauma.

## Key findings

- Localized bullous pemphigoid developed along a surgical scar one month after orthopedic surgery.
- Histology and immunofluorescence confirmed the diagnosis of bullous pemphigoid.
- Topical corticosteroid therapy led to clinical improvement.

## Abstract

Bullous pemphigoid (BP) is the most common autoimmune blistering disease in the elderly. Although usually spontaneous, it may be triggered by skin trauma. We report the case of a 90-year-old woman who developed localized BP along a surgical scar one month after orthopedic surgery. Lesions later spread to the trunk. Histology revealed a subepidermal blister with eosinophils, and immunofluorescence confirmed C3 deposition in addition to circulating anti-BP180 antibodies. Clinical improvement was observed following the initiation of topical corticosteroid therapy.