Interpretation of abrasion distribution and recognition of ant erosions
THE CONTEXT
The location and appearance of abrasions can help reconstruct a fall or assault, connect injuries with objects or scenes, and distinguish injury mimics.
Falls and signs of struggle
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Abrasions on an assailant's face or body indicate a struggle.
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Collapse due to a heart attack tends to cause a forward fall, producing abrasions of the eyebrow, nose and cheek without upper-limb injuries.
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A conscious person may extend the hands during a fall and sustain palmar abrasions.
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An alcoholic tends to fall backwards and strike the occiput.
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The passage describes fabricated assault allegations involving self-produced abrasions on accessible areas such as the front of the forearms or face.
Medicolegal interpretation
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Abrasions indicate the impact site and direction of force and may be the only external signs of serious internal injury.
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Patterned abrasions can connect a wound with its causative object. Injury-age assessment may help corroborate the alleged time of assault.
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Dirt, dust, grease or sand in an open wound may connect the injury with the crime scene.
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Throttling may produce crescentic fingernail abrasions on the neck; smothering may produce abrasions around the mouth and nose.
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In sexual assault, abrasions may occur on the breasts, genitals, inner thighs and around the anus.
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A victim's abrasions may indicate whether the assailant's fingernails were long, irregular or broken.
Ant erosions as an abrasion mimic
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Ants produce brown superficial erosions with minute, irregular margins that may simulate antemortem abrasions.
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Common sites include mucocutaneous junctions, eyelids, nostrils, mouth, ears, knuckles, axillae, groins, genitalia and moist skin folds.
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A hand lens reveals multiple crescent-shaped, sand-like bite marks, each separated by normal skin.