What is the term used to describe the powder burns and abrasions around a firearm entrance wound when the gun is fired from a distance of 15–90 cm?

Explanation

## Powder Burns and Tattooing in Firearm Injuries **Key Point:** Tattooing (also called stippling or powder tattooing) refers to small punctate abrasions and bruises caused by unburned and partially burned powder grains striking the skin around an entrance wound. ### Range Classification and Wound Patterns ```mermaid flowchart TD A[Firearm Discharge]:::outcome --> B{Distance from target?}:::decision B -->|Contact/Muzzle pressed| C[Contact wound]:::action C --> C1[Soot inside wound tract<br/>Thermal burns<br/>Marginal abrasion present] B -->|Close range < 1 m| D[Close range wound]:::action D --> D1[Tattooing/Stippling<br/>Soot deposition<br/>Marginal abrasion] B -->|15-90 cm| E[Intermediate range]:::action E --> E1[Tattooing/Stippling<br/>No soot<br/>Marginal abrasion] B -->|> 90 cm| F[Distant wound]:::action F --> F1[Only marginal abrasion<br/>No tattooing<br/>No soot] ``` ### Tattooing (Stippling) Characteristics - **Distance range:** 15–90 cm (approximately 6 inches to 3 feet) - **Cause:** Unburned and partially burned powder grains strike skin with enough velocity to cause abrasion/bruising but insufficient velocity to penetrate - **Appearance:** Small, discrete, reddish-brown punctate marks - **Permanence:** Cannot be wiped off (unlike soot) - **Forensic significance:** Helps estimate range of fire ### Distinction from Soot Deposition - **Soot:** Fine black powder residue, can be wiped off, seen at closer ranges (< 15 cm) - **Tattooing:** Mechanical abrasion by powder grains, cannot be wiped off, seen at intermediate range (15–90 cm) **High-Yield:** Tattooing is a permanent mark caused by mechanical impact of powder grains and is NOT present beyond 90 cm. It is a key indicator of intermediate-range fire. **Clinical Pearl:** In forensic autopsy, if tattooing is present around an entrance wound, the gun was fired from 15–90 cm away. Beyond this range, only the marginal abrasion collar is visible. **Mnemonic:** **STAB** for Stippling/Tattooing: **S**mall punctate marks, **T**emporary distance (15–90 cm), **A**brasions by powder, **B**ruising (cannot be wiped off).