Koebner Phenomenon
Pronunciation: KEB-ner feh-NOM-ih-non
The appearance of new skin lesions at sites of cutaneous trauma or mechanical injury in patients with certain pre-existing dermatoses.
Full Definition
The Koebner phenomenon (also Köbner phenomenon) describes the isomorphic response whereby trauma to uninvolved skin triggers the development of lesions characteristic of a patient's existing skin condition, most classically psoriasis and vitiligo. In dermatology publications, both spellings — 'Koebner' and 'Köbner' — are encountered; editors should apply the publication's house style consistently and note that the umlaut form is the original eponym. It should always be capitalised as an eponymous term. Editors must not confuse it with the 'pseudo-Koebner' effect, which involves inoculation of infectious agents at trauma sites rather than isomorphic autoimmune activity.
Usage
Usage note: Capitalise 'Koebner' as an eponym. Accept both 'Koebner' and 'Köbner' but ensure intra-document consistency. Always hyphenate 'pseudo-Koebner.'
In Context
- "New psoriatic plaques appeared along the surgical scar, consistent with the Koebner phenomenon." — Post-operative clinical note
- "The editor queried whether 'Koebner' should carry an umlaut per the original German eponym." — Peer-review correspondence