howMed Know Yourself
An abrasion is a superficial injury caused by friction or pressure between the epidermis and some blunt object.
Only superficial layer of the skin is involved, due to which it bleeds less and heals without scarring.
Types
- Scratch
- Graze (brush burn)
- Imprint or contact or patterned abrasion
- Friction abrasion
1. Scratch
It is a linear injury caused by a sharp object running across the skin, such as a nail.
The scratched epithelium is carried in front of the object and heaped up at the end, it indicates the direction of the object causing it.
2. Graze
When a broad surface of skin scratches against some surface, such as dragging a body on the road.
It resembles a burn –thus is also called a brush burn.
Initially there is a serrated border; and then a heaped up epithelium at the end. Distribution on the body depends on the position in which it was dragged.
3. Imprint or Contact or Patterned Abrasion
It is produced by a direct, vertical pressure by direct impact of an object on the body surface; it leaves its impression.
The shape of the object can be identified e.g.
- Ligature mark in strangulation
- Muzzle mark in contact fire arm injury
- Beating (Whip marks)
- Throttling (nail and thumb marks)
4. Friction Abrasion
These are produced by pressure of some linear object, accompanied with sliding movement.
E.g. abrasions around ligature mark in hanging and strangulatin
Anetmortem or Postmortem?
| Antemortem | Postmortem |
| Reddish brown to black in color | Yellowish and translucent |
| Blurred margins | Sharp edges |
| Surface is moist | Surface is dry |
| Scab formation | No scab formation |
| Inflammatory reaction | No inflammatory reaction |
Age of an Abrasion
| Bright red | Fresh |
| Red scab | 12-24 hours |
| Reddish brown scab | 2-3 days |
| Healing | 4-7 days |
| Healing complete | 7-10 days |
| Healing complete | 7-10 days |
Forensic Significance
- Site of impact –sometimes it may be the only external sign of a serious internal injury e.g. rupture of a viscera due to kick on abdomen
- Identification of object (in patterned abrasion)
- Circumstances of injury (e.g. about mouth and nose in smothering, genitals and thighs in rape)
- Direction of injury
- Time of injury
Helps in reconstruction of events
Bird Feet pattern of Abrasion
Multiple lacerations and abrasions following impact of the face with a broken car windscreen.
