The Koebner phenomenon or Köbner phenomenon (, ),
also called the Koebner response or the isomorphic response, attributed to
Heinrich Köbner, is the appearance of
skin lesions on lines of trauma. The Koebner phenomenon may result from either a linear exposure or irritation. Conditions demonstrating linear lesions after a linear exposure to a causative agent include:
molluscum contagiosum,
warts and
toxicodendron dermatitis
''Toxicodendron'' is a genus of flowering plants in the sumac family, Anacardiaceae. It contains trees, shrubs and woody vines, including poison ivy, poison oak, and the lacquer tree. All members of the genus produce the skin-irritating o ...
(a
dermatitis caused by a genus of plants including
poison ivy). Warts and molluscum contagiosum lesions can be spread in linear patterns by self-scratching ("
auto-inoculation"). Toxicodendron dermatitis lesions are often linear from brushing up against the plant. Causes of the Koebner phenomenon that are secondary to scratching rather than an infective or chemical cause include
vitiligo,
psoriasis,
lichen planus,
lichen nitidus,
pityriasis rubra pilaris, and
keratosis follicularis (Darier disease).
Definition
The Koebner phenomenon describes skin lesions which appear at the site of injury. It is seen in:
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Psoriasis
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Pityriasis rubra pilaris
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Lichen planus
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Flat warts
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Lichen nitidus
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Vitiligo
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Lichen sclerosus
:*
Elastosis perforans serpiginosa
Elastosis perforans serpiginosa is a unique perforating disorder characterized by transepidermal elimination of elastic fibers and distinctive clinical lesions, which are serpiginous in distribution and can be associated with specific diseases.Free ...
:*
Kaposi sarcoma
:*
Necrobiosis lipoidica
Necrobiosis lipoidica is a necrotising skin condition that usually occurs in patients with diabetes mellitus but can also be associated with rheumatoid arthritis. In the former case it may be called necrobiosis lipoidica diabeticorum (NLD). NLD ...
:*
Lupus
Lupus, technically known as systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Comm ...
:*
Juvenile Idiopathic Arthritis
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Still disease
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Cutaneous leishmaniasis
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Post kala azar dermal leishmaniasis
A similar response occurs in
pyoderma gangrenosum and
Behcet's syndrome, and is referred to as
pathergy Pathergy is a skin condition in which a minor trauma such as a bump or bruise leads to the development of skin lesions or ulcers that may be resistant to healing. Pathergy can also lead to ulcerations at the site of surgical incisions. Pathergy is ...
.
Rarely Koebner phenomenon has been reported as a mechanism of acute myeloid leukemia dissemination.
Warts and molluscum contagiosum are often listed as causing a Koebner reaction, but this is by direct inoculation of viral particles.
The linear arrangement of skin lesions in the Koebner phenomenon can be contrasted to both
lines of Blaschko
Blaschko's lines, also called the lines of Blaschko, are lines of normal cell development in the skin. These lines are only visible in those with a Mosaic (genetics), mosaic skin condition or in Chimera (genetics), chimeras where different cell li ...
and dermatomal distributions. Blaschko lines follow embryotic cell migration patterns and are seen in some mosaic genetic disorders such as
incontinentia pigmenti and
pigment mosaicism.
Dermatomal distributions are lines on the skin surface following the distribution of spinal nerve roots. The rash caused by herpes zoster (
Shingles
Shingles, also known as zoster or herpes zoster, is a viral disease characterized by a painful skin rash with blisters in a localized area. Typically the rash occurs in a single, wide mark either on the left or right side of the body or face. ...
) follows such dermatomal lines.
History
The Koebner phenomenon was named after the rather eccentric but renowned German dermatologist
Heinrich Koebner
Heinrich Koebner (German spelling Köbner); (2 December 1838 – 3 September 1904) was a German Jew, German-Jewish dermatologist born in Breslau.
He studied medicine in Berlin, earning his doctorate in 1859 at Breslau. Afterwards he performed ...
[In the ]anglicisation
Anglicisation is the process by which a place or person becomes influenced by English culture or British culture, or a process of cultural and/or linguistic change in which something non-English becomes English. It can also refer to the influen ...
of a German word, double vowels are often substituted for the Germanic umlaut
The Germanic umlaut (sometimes called i-umlaut or i-mutation) is a type of linguistic umlaut in which a back vowel changes to the associated front vowel ( fronting) or a front vowel becomes closer to (raising) when the following syllable conta ...
on single vowels. The transformation of "Köbner" to "Kooebner" is just such a case. In the English literature, the umlaut is simply dropped and you often find "Köbner" simply as "Kobner". (1838–1904). Koebner is best known for his work in
mycology. His intense nature is illustrated by the following: in a medical meeting, he proudly exhibited on his arms and chest three different fungus infections, which he had self-inoculated, in order to prove the infectiousness of the organisms he was studying. The Koebner phenomenon is the generalized term applied to his discovery that on psoriasis patients, new lesions often appear along lines of trauma.
See also
*
Renbök phenomenon In the field of dermatology, the Renbök phenomenon is a phenomenon where one skin condition inhibits another. It is also known as the reverse Koebner phenomenon. The term was first used by Happle et al. in 1991. The word "Renbök" is a neologism, ...
References
Sources
* Crissey JT, Parish LC, Holubar KH. Historical Atlas of Dermatology and Dermatologists. New York: The Parthenon Publishing Group, 2002.
* Paller A, Mancini A. Hurwitz Clinical Pediatric Dermatology. Philadelphia: Elsevier Saunders, 2002.
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Dermatologic signs