Which type of scars are thick and raised due to excessive collagen production?

Keloid scars are a type of thick, raised scar that form as a result of excessive collagen production during the healing process. When the skin is injured, the body produces collagen to help repair the damage. In some individuals, this collagen production can go into overdrive, leading to a keloid, which extends beyond the original site of injury. Keloids often appear smooth, hard, and can be discolored compared to the surrounding skin. They can develop from various types of skin injuries, including surgical incisions, cuts, or even insect bites. The overproduction of collagen causes these scars to be raised and sometimes itchy or painful, which differentiates them from other types of scars.

Other options represent different skin conditions: striae (stretch marks) occur due to rapid skin stretching and are flat, cellulitis is a bacterial skin infection causing redness and swelling but not specifically related to scarring, and verrucae filliformis refers to a type of wart that is usually not raised or thick in the manner of keloid scars.