What is the term used to describe the small abrasions and contusions around the margin of an entrance wound caused by the bullet scraping the skin as it enters?

Explanation

## Abrasion Collar in Firearm Injuries **Key Point:** The abrasion collar (also called marginal abrasion) is a pathognomonic feature of entrance wounds and is formed by the bullet scraping the epidermis as it penetrates. ### Formation Mechanism 1. Bullet strikes the skin at high velocity 2. Kinetic energy causes the bullet to scrape and abrade the epidermis and superficial dermis 3. Creates a ring of abraded, discolored skin around the entrance wound 4. Forms a characteristic dark rim around the wound opening ### Characteristics of Abrasion Collar **High-Yield:** The abrasion collar is: - Present in ENTRANCE wounds only - Formed by mechanical scraping of the epidermis - Appears as a dark, discolored ring around the wound - More prominent in contact and near-contact shots - Can be wiped away with gentle cleaning (unlike tattooing) - Useful for determining wound direction ### Distinction from Related Terms | Term | Definition | Location | |------|---|---| | **Abrasion collar** | Scraped epidermis from bullet entry | Entrance wound margin | | **Soot/Fouling** | Unburned powder residue | Contact/near-contact entrance wounds | | **Tattooing** | Powder grain impacts on skin | Near-contact entrance wounds | | **Beveling** | Bone fracture pattern | Entrance/exit through bone | **Mnemonic:** **ABRASION = Entrance** — Remember that the Abrasion collar marks the entrance wound, formed by the bullet ABRading the skin as it enters. **Clinical Pearl:** In decomposed or charred bodies, the abrasion collar may be the only reliable feature to identify entrance wounds when other markers are destroyed.