Fig. 15. Scratches caused by needle (damage itself).

Abrasion (sadnenia) - violations of the integrity of the epidermal at the tangential impact of the breaking of the subject. Peel and offset of the epidermis most often occur in the depth of germ layer, at least - at the level of the tops of the papillae of the skin. The surface of the arisen sadnenia wet, pink-red color, is located slightly below the level of the adjacent intact skin. Linear abrasions are designated as scratches (Fig. 15).
Microscopic examination abrasion shows that the epidermis is rarely removed entirely - retained its separate Islands, consisting of all walks or only from the basal layer cells. The dermis in the field abrasion seems basophilic and homogenized, her nipples exposed. A few hours after the injury surface abrasions covered with a crust, consisting of dried cells maleyeva layer proteins lymph and clotted blood. After 1-4 days a level surface abrasion is levelled and begins to rise above the border areas of the skin. The healing process - epithelialization - comes from the periphery abrasion to its Central part with the gradual separation of brown. The broken crust uncovers a plot of sadnenia, which is more dense, smooth and depigmentirovannah than damaged skin. Gradually these symptoms disappear.
The healing of abrasion depends on many factors (gender, age, diseases and other), including on their location. Faster bruises heal on the head and neck (up to 12 days), then on the front surface of the trunk and extremities (14-15 day). Longer heal bruises on the back of the lower extremities (17 days) and back (18-20 day).
A study by the method of direct microscopy shows that at the beginning abrasion epidermis exactly or indirectly torn, and in the end turned toward the intact skin or rises above it.
On the surface abrasion at macro - and microscopy sometimes detect particles damaging of the object (pieces of wood, sand, coal dust specks, lubricating oils, metallization and others). When damaged metal objects metallization determine, for example, by the method of color prints.
Form abrasion sometimes one can judge about the path of damaging of the object (for example, abrasion caused by the free edge of the nail).
The study of the boundary between the intact skin and parcel of sadnenia in typical cases shows that one end abrasion generally flat or undulating, another steep, saped that indicates the direction of the damaging of the object.
The nature and type of abrasion judge can judge about the limitations of causing damage, the method of its application and features of damaging the surface. Unlike bruises localization abrasion always points to the impact of damaging the subject.
Lifetime abrasion must be differentiated from the resulting posthumously parchment spots. Diagnostics aimed at establishing the presence of reactive processes occurring on the border between sednenie and intact skin.