Final answer:
The Koebner phenomenon, also known as the isomorphic response, refers to the appearance of new psoriatic lesions at sites of skin injury in patients with psoriasis. This is due to the rapid cell turnover and inflammation characteristic of psoriasis, which can be exacerbated by scratching.
Step-by-step explanation:
In patients with psoriasis, the phenomenon where scratching leads to more lesions is referred to as the Koebner phenomenon or isomorphic response. This occurs due to the abnormal rapid turnover of skin cells that is characteristic of psoriasis, where instead of taking about a month for skin cells to mature and reach the surface, this process occurs in just a few days. This accelerated cell turnover, combined with inflammation and the disruption of the skin barrier from scratching, can lead to the development of new psoriatic lesions at sites of injury.
Psoriasis is a chronic skin disorder that results in itchy or sore patches of thick, red skin with silvery scales, most commonly affecting areas like elbows, knees, scalp, back, face, palms, and feet. The presence of skin lesions in psoriasis increases the susceptibility to secondary injuries and infections, making it important for individuals to manage their scratching behavior to prevent worsening of the condition.