SN2 SHORT NOTE 5M ★ High-yield

Describe scars and their medicolegal importance.

Forensic Medicine · 2nd Professional — Para-Clinical

Definition and Formation

A scar (cicatrix) is the fibrous tissue that replaces the normal tissue destroyed by injury or disease. It forms only where the injury has extended into the dermis; an injury confined to the epidermis heals without a scar.

Structure — avascular, glistening fibrous tissue without hair follicles, sweat or sebaceous glands, or pigment. It therefore does not sweat, does not grow hair, and does not tan — features that distinguish a true scar from other marks
Evolution — initially red and vascular, becoming pale, white and glistening over months; it contracts with time, so an old scar is smaller than the original wound and may be materially smaller in a child who has grown
The scar reproduces the shape of the wound that caused it, which is the basis of most inferences drawn from it

Original injury	Character of the scar
Incised wound	Linear, regular and thin
Lacerated wound	Irregular, broad and puckered
Burn or scald	Broad, irregular, thick and often keloid, with marked contracture, deformity and limitation of movement; depigmented with hyperpigmented margins
Acid (corrosive) burn	Irregular with streaks running downward from the site, following the dripping of the liquid, which is highly characteristic and indicates the position of the person when it was thrown
Ulcer of chronic disease	Large, irregular, adherent to underlying tissue and often pigmented
Smallpox (historical)	Multiple small, circular, depressed and pitted scars, mainly on the face
Surgical scar	Linear and regular, in a recognised anatomical line, often with suture marks — and it indicates the operation performed, which may identify a person through hospital records
Vaccination (BCG) scar	Small, circular and depressed, characteristically over the left deltoid — indicating vaccination and thus a broad indication of age and of nationality

CLINICAL PEARL

A scar contracts, so it is smaller than the wound that made it — and in a child it may be far smaller. A doctor asked whether a 2 cm scar could have been caused by a 5 cm wound sustained in childhood should say yes, with reasoning: the scar shrinks, and the body has grown around it disproportionately in some regions. Inferring the original size of a wound from an old scar is unsafe, and saying so is more useful than an estimate that cannot be defended.

Medicolegal Importance

Identification — scars are among the standard identification marks recorded in every medicolegal case, and their site, size, shape and character are described and measured from a fixed bony landmark
The nature of the original injury — whether incised, lacerated, burnt or surgical, which may support or contradict an account given
The age of the injury — a broad estimate only. A scar is red and vascular for the first few weeks to months, becomes pale over 6 months to a year, and thereafter cannot be dated. An opinion on the age of an old scar should be expressed as a wide range or declined
The cause and manner — multiple parallel scars of uniform depth on accessible parts suggest self-infliction or previous self-harm; scars of different ages in a child suggest repeated abuse; and the streaked scars of a corrosive suggest an acid attack
Disability and compensation — a scar causing disfigurement, contracture or functional loss is relevant to the assessment of grievous hurt (permanent disfigurement of the head or face is expressly grievous), to compensation, and to fitness for employment
Evidence of past disease or operation — a laparotomy scar, an amputation, a tracheostomy scar, or the scars of tuberculous lymphadenitis

Distinction from Other Marks, and Applied Aspects

A scar is distinguished from an artificial or feigned mark by its structure: a true scar has no hair, no glands and no pigment, does not sweat, and is firmly continuous with the surrounding skin. Marks produced by dyes, chemicals or adhesive plaster lack these features and can be removed or washed
Distinguished from postmortem changes and artefacts — a scar has a vital reaction and a fibrous structure on histology; ant bites, decomposition and pressure marks do not
Keloid extends beyond the original wound margins and continues to grow, whereas a hypertrophic scar remains within them and eventually regresses; keloid is commoner in darker skin and over the sternum, shoulder and ear lobe
Describe and measure every scar from fixed landmarks, and photograph it with a scale; "scar on the arm" is worthless in a report
Do not date an old scar confidently; state that it is more than a stated period old and that a closer estimate cannot be made, which is honest and unassailable
Look for scars of different ages in a child, and for scars in protected sites; a pattern of injuries of varying age is one of the strongest indicators of repeated abuse and should prompt child protection action
Record a BCG scar and its absence; it is a small but genuine aid to identification and to the assessment of nationality and vaccination history

All questions in Identification

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