The Koebner phenomenon or Köbner phenomenon (, ), also called the Koebner response or the isomorphic response, attributed to

Heinrich Köbner 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 ...

, is the appearance of

skin lesion A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this ...

s 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 Molluscum contagiosum (MC), sometimes called water warts, is a viral infection of the skin that results in small raised pink lesions with a dimple in the center. They may become itchy or sore, and occur singularly or in groups. Any area of the ...

wart Warts are non-cancerous viral growths usually occurring on the hands and feet but which can also affect other locations, such as the genitals or face. One or many warts may appear. They are distinguished from cancerous tumors as they are caus ...

s and toxicodendron dermatitis (a

dermatitis Dermatitis is a term used for different types of skin inflammation, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened ...

caused by a genus of plants including

poison ivy Poison ivy is a type of allergenic plant in the genus '' Toxicodendron'' native to Asia and North America. Formerly considered a single species, '' Toxicodendron radicans'', poison ivies are now generally treated as a complex of three separate s ...

). 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 Vitiligo (, ) is a chronic autoimmune disorder that causes patches of skin to lose pigment or color. The cause of vitiligo is unknown, but it may be related to immune system changes, genetic factors, stress, or sun exposure, and susceptibili ...

psoriasis Psoriasis is a long-lasting, noncontagious autoimmune disease characterized by patches of abnormal skin. These areas are red, pink, or purple, dry, itchy, and scaly. Psoriasis varies in severity from small localized patches to complete b ...

lichen planus Lichen planus (LP) is a chronic inflammatory and autoimmune disease that affects the skin, nails, hair, and mucous membranes. It is not an actual lichen, but is named for its appearance. It is characterized by polygonal, flat-topped, violaceous p ...

, lichen nitidus,

pityriasis rubra pilaris Pityriasis rubra pilaris refers to a group of chronic disorders characterized by reddish orange, scaling plaques and keratotic follicular papules.Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. ...

, and keratosis follicularis (Darier disease).

Definition

The Koebner phenomenon describes skin lesions which appear at the site of injury. It is seen in: :*

Psoriasis Psoriasis is a long-lasting, noncontagious autoimmune disease characterized by patches of abnormal skin. These areas are red, pink, or purple, dry, itchy, and scaly. Psoriasis varies in severity from small localized patches to complete b ...

Pityriasis rubra pilaris Pityriasis rubra pilaris refers to a group of chronic disorders characterized by reddish orange, scaling plaques and keratotic follicular papules.Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. ...

Lichen planus Lichen planus (LP) is a chronic inflammatory and autoimmune disease that affects the skin, nails, hair, and mucous membranes. It is not an actual lichen, but is named for its appearance. It is characterized by polygonal, flat-topped, violaceous p ...

Flat warts Flat warts, technically known as verruca plana, are reddish-brown or flesh-colored, slightly raised, flat-surfaced, well-demarcated papule of 2 to 5 mm in diameter. Upon close inspection, these lesions have a surface that is "finely verrucou ...

:* Lichen nitidus :*

Vitiligo Vitiligo (, ) is a chronic autoimmune disorder that causes patches of skin to lose pigment or color. The cause of vitiligo is unknown, but it may be related to immune system changes, genetic factors, stress, or sun exposure, and susceptibili ...

Lichen sclerosus Lichen sclerosus (LS) is a chronic, inflammatory skin disease, of unknown cause, which can affect any body part of any person, but has a strong preference for the genitals (penis, vulva), and is also known as balanitis xerotica obliterans when i ...

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.Fre ...

Kaposi sarcoma Kaposi's sarcoma (KS) is a type of cancer that can form masses on the skin, in lymph nodes, in the mouth, or in other organs. The skin lesions are usually painless, purple and may be flat or raised. Lesions can occur singly, multiply in a limite ...

Necrobiosis lipoidica Necrobiosis Lipoidica is a rare, chronic skin condition predominantly associated with diabetes mellitus (known as necrobiosis lipoidica diabeticorum or NLD). It can occur in individuals with rheumatoid arthritis or without any underlying conditions ...

Lupus Lupus, formally called 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. Common ...

Juvenile Idiopathic Arthritis Juvenile idiopathic arthritis (JIA), formerly known as juvenile rheumatoid arthritis (JRA), is the most common chronic rheumatic disease of childhood, affecting approximately 3.8 to 400 out of 100,000 children. ''Juvenile'', in this context, ref ...

:* Still disease :*

Cutaneous leishmaniasis Cutaneous leishmaniasis is the most common form of leishmaniasis affecting humans. It is a skin infection caused by a Trypanosomatid, single-celled parasite that is Vector (epidemiology), transmitted by the bite of a Phlebotominae, phlebotomine s ...

Post kala azar dermal leishmaniasis Leishmaniasis is a wide array of clinical manifestations caused by protozoal parasites of the Trypanosomatida genus ''Leishmania''. It is generally spread through the bite of phlebotomine sandflies, ''Phlebotomus'' and ''Lutzomyia'', and o ...

:* Eruptive xanthomas :* Urticaria A similar response occurs in

pyoderma gangrenosum Pyoderma gangrenosum is a rare, Inflammation, inflammatory skin disease where painful pustules or skin condition, nodules become ulcer (dermatology), ulcers that progressively grow. Pyoderma gangrenosum is not infectious. Treatments may include ...

and Behcet's syndrome, and is referred to as pathergy. 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 and dermatomal distributions. Blaschko lines follow embryotic cell migration patterns and are seen in some mosaic genetic disorders such as

incontinentia pigmenti ''Incontinentia pigmenti'' (IP) is a rare X-linked dominant genetic disorder that affects the skin, hair, teeth, nails and central nervous system. It is named from its appearance under a microscope. The disease is characterized by skin abnormal ...

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 herpes zoster or zona, 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. T ...

) follows such dermatomal lines.

History

The Koebner phenomenon was named after the rather eccentric but renowned German dermatologist Heinrich KoebnerIn the

anglicisation Anglicisation or anglicization is a form of cultural assimilation whereby something non-English becomes assimilated into or influenced by the culture of England. It can be sociocultural, in which a non-English place adopts the English language ...

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 (linguistics), umlaut in which a back vowel changes to the associated front vowel (fronting (phonology), fronting) or a front vowel becomes closer to ...

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 Mycology is the branch of biology concerned with the study of fungus, fungi, including their Taxonomy (biology), taxonomy, genetics, biochemistry, biochemical properties, and ethnomycology, use by humans. Fungi can be a source of tinder, Edible ...

. 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.

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. {{DEFAULTSORT:Koebner Phenomenon Dermatologic signs

Definition

History

See also

References

Sources