Dermatofibromas are benign pea-sized growths that occur on the arms and legs. They are firm to touch and attached to the overlying skin which may be darker than the surrounding skin. They often occur as a result of a bug bite or an ingrown hair that does not heal normally and this scar like bump that is called a Dermatofibroma forms. These growths are composed of collagen bundles and may be single or multiple. Surgery is usually required to remove them entirely.