Abrasions

FULL DESCRIPTION

1. ABRASIONS PRESENTED BY :- SUBMITTED TO : RUCHIT PATEL GOVT. MEDICAL COLLEGE, BHAVNAGAR

2. INTRODUCTION Type of MECHANICAL injury. Due to BLUNT force. Destruction of the skin which usually invloves the SUPERFICIAL LAYERS of the EPIDERMIS only. Also known as GRAVEL RASH .

3. MECHANISM Caused by :- (a.)FRICTION against a rough surface (b.)By COMPRESSION, such as - lateral rubbing action by a blow - by being dragged in a vehicular accident - fingernails - thorns - teeth bite The epidermal cells are flattened and their nuclei are elongated. The rougher the surface, and the more rapid the movement of the skin over it, the deeper is the injury.

4. MECHANISM The exposed raw surface is covered by exudation of lymph and blood which produces a protective covering known as a SCAB or CRUST . They are simple injury, bleed slightly, heal rapidly and SCAR IS NOT FORMED.

5. TYPES OF ABRASIONS Scratches Grazes Pressure abrasions Impact abrasions

6. SCRATCHES/ LINEAR ABRASION Has length but no significant width. Caused by SHARP/POINTED objects like :- - fingernails - pin - thorn A scratch produced from tip of a knife or razor is called as POINT SCRATCH .

7. GRAZES/GLIDING/SLIDING ABRASION Most common type. Movement between skin and some rough surface in contact with it. Uneven, longitudinal parallel lines with epithelium headed up at the ends of these lines, which indicates the direction in which the force is applied .

8. The furrow may be broad at one end and narrow at the other end. Commonly seen in road accidents. a glancing kick with a boot is also a graze.

9. PRESSURE ABRASIONS Caused by CRUSHING of the superficial layers of the epidermis. Associated with a bruise of the surrounding area. If movement of the instrument is around 90 degrees to the skin, pressure abrasion is produced. Force of impact – less Duration - more Examples :- - ligature mark in cases of hanging and strangulation. - teeth bite marks.

10. IMPACT ABRASIONS Caused by impact with a rough object when force is applied at right angle to the skin surface. Force of impact- high Duration – less Example – a person getting hit by a car.

11. PATTERNED ABRASION Subtype of impact/ pressure abrasion Reproduce the pattern of the object causing it. Force is applied at right angle to skin surface. Examples- - imprint of bicycle chain - ropes

12. AGE OF ABRASIONS Fresh – Bright red 12 to 24 hours – Bright red scab (blood and lymph dries up) 2 to 3 days – Reddish-Brown scab 4 to 7 days – Dark brown to Brownish-Black scab After 7 days – Scab dries and falls off, leaving depigmented area with gets pigmented gradually.

13. DIFFERENCE BETWEEN ANTEMORTEM AND POSTMORTEM ABRASIONS ANTEMORTEM ABRASIONS SITE- Anywhere on the body. COLOUR- Bright reddish-brown. EXUDATION- More SCAB- Raised MICROSCOPIC- Intravital reactions and congestion seen POSTMORTEM ABRASIONS Usually over bony prominences. Yellowish translucent. Less Below the level of skin. No intravital reactions and no congestion.

14. MEDICOLEGAL IMPORTANCE Give idea about the site of impact and direction of force. Patterned abrasions help in identifying the object of injury. The age of the injury can be determined. Character and manner of the injury can be known, e.g. in SEXUAL ASSAULT, abrasions may be found on the breasts, genitals, inside of the thighs, and around the anus.

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