[This phenomenon is also termed the isomorphic response]
Appearance of new skin lesions on previously unaffected skin secondary to trauma.
Koebner phenomenon seen in –
- Lichen planus
Koebnerization – function as a clinical indicator of disease activity in vitiligo, as well as serve as a predictor of treatment response
Other conditions have demonstrated the Koebner phenomenon
- leukocytoclastic vasculitis
- mycosis fungoides
- eruptive xanthomas
Classification and Subtypes of the Koebner Phenomenon
Boyd and Nelder classified
First group [category I] referred to as true koebnerization,
- lichen planus,
Koebner phenomenon is reproducible in all patients by a variety of insults.
Boyd and Nelder argued that the term Koebner phenomenon should be typically reserved for this group of diseases.
Second group [category II] –pseudo-koebnerization,
- molluscum contagiosum
- verruca vulgaris
whereby the Koebner phenomenon gets produced by the seeding of infectious agents along with sites subjected to trauma, usually from scratching.
Third group [category IIII], occasional lesions,
- Darier disease
- Erythema multiforme,
which meet some criteria for the Koebner phenomenon but not all.
Fourth group [category IV] – questionable trauma-induced process, includes all disorders with a dubious association with trauma, such as pemphigus vulgaris and lupus erythematosus.