Koebner phenomenon in autoimmune bullous dermatoses: a scoping review of documented cases

The Koebner phenomenon (KP), also known as the isomorphic response, is the appearance of new dermatologic lesions in individuals with preexisting dermatoses. While KP is well-documented in immune-mediated skin conditions, its role in autoimmune bullous diseases (AIBDs), such as pemphigus vulgaris (PV) and bullous pemphigoid (BP), is less understood. This review synthesizes reported cases of KP in AIBD, focusing on triggers, manifestations, and treatment modalities. A literature review was conducted using PubMed including studies from January 2000 to January 2025 focusing on KP in AIBD. A total of 18 eligible articles were included in a qualitative synthesis, yielding 56 cases of KP in AIBD. The mean patient age was 59.61 years (range: 26–97). Most cases (n = 50/56, 89.3%) were mechanically induced (e.g., surgery, trauma), while medications/procedures (n = 2/56, 3.6%) and infections (n = 2/56, 3.6%) were rare triggers. PV (n = 41/56, 73.2%) and BP (n = 6/56, 10.7%) were the most frequently reported AIBDs, often localized to surgical sites. Treatment primarily involved corticosteroids, including combination therapy with immunosuppressive agents, resulting in significant improvement or complete resolution in nearly all cases (four studies did not report outcomes), with no reported mortality. Trauma-induced KP is the most common form in AIBD, often occurring in older individuals with PV and BP. Surgical procedures, in particular, should be conducted carefully in pre-existing AIBD patients to minimize the risk of KP. Personalized preventive measures, including minimizing trauma and considering adjustments to immunosuppressive therapy, are essential for improving patient outcomes.