Types of thermal injuries
Definition
Old classification Recent classification
 Dry or simple burn.
degree burn
AFirst
thermal
injury is a tissue
injurydegree
resulting
Epidermal
1st & 2nd degree

Scald
or
moist
burn.
Secondthe
degree
burn
from
application
of
heat
in
any
form
to
By
the
external
or
surface
of the burn
body.
Third
degree burn

Chemical
orinternal
corrosive
burn.
Dermo
- epidermal
Fourth degree burn
3rd & 4th degree
 Electric burn.
Lecturer of Forensic Medicine & Clinical Toxicology
Fifth
degree burn
Deep burn
 Radiation burn.
5th & 6th degree
Sixth degree burn
Dry burn
Any degree
Degree
Air passage Contains soot
Hair
Blood
Skin
Cause
Singed
Thick, viscid &
contains COHb
Dry & charred
Flame or
heated
body
Thick with
Scar
disfigurement
Burnt
Clothes
From below
Site & spread upward
Charring
Vesicles
At circumference
Present of
burnt area
Scald
1st, 2nd
&
No soot
3rd
Wet
Sodden & bleached
Steam or hot
Less
liquid
disfigurement
Wet
From
above
downward
Absent
Over burnt area
Corrosive
1st, 3rd, 4th
No soot
Eaten
Stained & corroded
Corrosive acid or
Much
alkali
disfigurement
Eaten
At & below site of
contact
With
mineral
Rarely found
acid
Factors affecting degree of burn
A) Extent of burnt area:
D)
Age
is determined
by rule of nine of Wallace.
B)
Depth
of
burn:
E) Sex
The 3rd degree burn is the most serious one.
F)Site
General
C)
of burn.health.
Neck, abdominal wall or genitalia are more
dangerous than those of the extremities.
Causes of death from burn
III)
Deathdeath
within
2-7
days:
I) Rapid
Immediate
causes
"within
6 hours“
II)
"within
6-48
hours”:
IV)
after
one
week:
- Supra-renal
haemorrhage.

Secondary
oligaemic
shock.
 Neurogenic
shock.
- Rupture of an acute duodenal ulcer (at 12th
day)
(curling'saccidental
ulcer) (stress
ulcer):
may
be due

Associated
serious
injuries
to
vital
- to
Bronchopneumonia.
hypovolaemia causing devitalization of
organs.
 Secondary toxaemic shock.
mucous membrane in addition to the absorbed
toxins which
excreted
by the liver into
- burn
Inflammation
ofare
serous
membranes.
 Asphyxia
(suffocation).
the duodenum.
 Acute oedema of glottis (in the neck).
 Traumatic asphyxia.
- Septicemia.
- Liver,
kidney
or
heart
damage:
cell
degeneration
and necrosis
of these organs due
Tetanus,
gangrene
and
erysipelas.:
 Pulmonary fat embolism (burn in a fatty area(.
to the effect of burn toxins metabolism.
Burn
vitality
Age
of Burn
Erythema
Appears
Antemortem
immediately
burn
36 hs
Appears
Line of hyperemia
Present
Vesicles
1w
2-3hs
Vesicles
Presence
of COHb
Sepsis
Vital
reaction
Superficial slough
Cause of death
Soot in URT
48 hs
Absent
2 ws
Albuminous fluid
absent poor in
rich in chloride
albumin and chloride
Present
Absent
2–3
36 hs
Infl., pus
1
healing
Nothing
But burn
days
w
Nil
Other causes
3 ws
Deep slough
Scar
Postmortem burn
Red
Present
2m
Coppery
Absent
6m
Postmortem
Picture
of Burn
Complications
of Burn
--Particles
soot are
present
the air
The bodyofshows
evidence
ofin
antemortem
passage.
burns of various degrees.
The body presents
a peculiar
attitude;hge
-- Subcutaneous
or subserous
peticheal
attitude
of defence,
boxing or "Pugilistic
may
be present
.
attitude".
Sepsis
Deformities
- Haemoconcentration
of blood
due
to loss
Keloid
formation
- Crimson
red cherry
colour red
of hypostasis.
of
plasma and
colour of the skin.
Generalized
visceral
congestion
Hge
--Skull
may show
thermal
fracture and
"fissure
in the internal
organs.
fracture“.
-
Points of differentiation () thermal & traumatic fracture
Thermal Fracture
The fracturesigns
is notofdisplaced
Postmortem
burn
The brain is shrunken
Extradural haematoma
doesn’t fill the space
Traumatic Fracture
The fracture
Other postmortem
signsisofdisplaced
death
The brain is edematous
& associated with contused wound in scalp
Extradural haematoma
fill the space
Factors influencing the effect of electric current
Electric
burn
Physical
Voltage
Physiological
Resistance of body
tissue
Humidity
Nature of current
Pathway of current
Anticipation of shock
Duration of contact
General health
Causes of Death
Ventricular fibrillation
Central
Respiratory failure
Peripheral
Cardiac arrest
Cerebral anoxia
Electric burn
Hyperthermic effect
Marks
P.M. PictureCurrent
of Electric
Burn
NMicroscopic
/ E appearance
appearance
- It
is
of
the
same
size
and
shape
as
the
-
Compression
of
the
stratum
corni
which
Rapid onset of rigor mortis
conductor.
stains
deeply with superficial carbonization.
 Marked hypostasis
Grayish-white
painless
areas
of
aseptic
- Separation of the cells in the form of slits
necrosis.
(electric channels).
 Presence of current mark
- They vary from superficial circumscribed
- Elongation of both cells and nuclei.
severe
burns with full thickness
lesions
Internaltosigns
of asphyxia
tissue necrosis.
-The electric current is DC not AC.
Lightning syndrome
Definition
Characterized
by:
-About
20.000 amperes.
It is the discharge of the atmosphere
Loss of consciousness.
potential () clouds, or () clouds and
-About
100 - 1000
million
volts.
st degree burn.
Earth.
Skin burn
(similar
to 1
Conductive
deafness.
- A single flash lasts 1/1000th of a second.