Abrasions (grazes or scrapes) are typically the result of tangential blunt force trauma exerting a dragging or frictional force to the superficial skin. Abrasions do not usually penetrate the full thickness of the epidermis, but may do so focally. Abrasions may bleed due to interruption of the dermal papillae. Typically, the end opposite to the point of impact shows heaped up epidermis (and therefore may have some forensic significance in determining the direction of the apparent force). Abrasions can be of varying type such as directional (brush type) resulting from contact with a rough surface (e.g. “road rash”) or finger nail scratches which are often short and curved. Assessment of age of abrasions in isolation may be difficult, but the absence of bleeding, the presence of scabbing, along with the appearance of any associated bruising may be helpful.
Figure 1. Abrasion to the forehead falling a fall.
Figure 2. Abrasion to the left cheek following contact with the floor.