Koebner phenomenon

Source = Wikipedia

Koebner phenomenon = skin lesions appearing on lines of trauma. It may result from either linear exposure or linear irritation.

Linear exposure:

• Molluscum contagiosum (auto-inoculation)
• Warts (auto-inoculation)
• Toxicodendron dermatitis (e.g. poison ivy... linear from brushing against plant).

Linear irritation, e.g. scratching or surgical wound:

• Psoriasis*
• Eczema*
• Lichen planus*
• Vitiligo*
• Lichen nitidus
• Lichen sclerosus
• Pityriasis rubra pilaris
• Keratosis follicularis
• Elastosis perforans serpiginosa.

*4 most common causes of Koebner phenomenon = PELV

The Koebner phenomenon was named after a rather eccentric, renowned German dermatologist, Heinrich Koebner (1838–1904). Koebner is best known for his work in mycology. Here is one story to illustrate his intense nature: in a medical meeting he proudly exhibited on his arms and chest three different fungus infections, which he self-inoculated in order to prove the infectiousness of the organisms he was studying.