What Causes Koebner's Phenomen Psoriasis?

The cause of the Koebner's phenomenon is unknown, however, it is more likely to occur before age 15. Up to 50% of psoriasis patients will experience new lesions forming at the site of healing wounds. Approximately 10% of psoriasis sufferers experience the Koebner's Phenomenon with every skin injury or condition, and its chances of occurring increase when the psoriasis is in an active stage.

While most often associated with psoriasis patients, a Koebner phenomenon, may occur in people affected with many other types of skin conditions including eczema, systemic juvenile rheumatoid arthritis, lichen planus, and warts. Skin conditions that have been found to trigger Koebner's phenomenon include: any type of dermatitis, a Herpes breakout, skin boils, Lichen Planus, and Vitilgo. Koebner's phenomenon can also result from trauma to the skin from such factors as insect bites; irritation resulting from a chemical reaction on the skin; injuries to the skin such as burns, bruises, cuts or scrapes, sunburn, or skin chafing; skin procedures such as tattoos or acupuncture. In some cases shaving or even the adhesive from a band-aid can result in Koebner's phenomenon. In rare instances, it has been known to occur at the site of an old scar.