BURNS – UNIT-1
INTRODUCTION
CHANDRASEKAR.L
LECTURER,
MAJMA’AH UNIVERSITY
Unit – 1 – Lecture Outline
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This lecture deals about the burns in the following
sub-categories;
1. Introduction, definition & causes of burns.
2. Classification of burns, Skin anatomy & functions
of it.
3. Pathophysiology of burns.
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Unit – 1 – Learning Objective
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At the end of this unit - 1, the students will acquire a comprehensive &
well found knowledge & develop the process of critical thinking, clinical
reasoning & exercise sound clinical judgment in the following;
1. Definition of burns
2. Major causes of burns
3. Anatomy, structure & functions of the skin
4. Classification of Burns
5. Differentiate between superficial, superficial partial thickness, deep
partial thickness, full thickness & sub-dermal burns.
6. Pathophysiology of burns
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INTRODUCTION
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Burns are one of the major Health problem of
Industrial world
U.S Annually records incidence of 2 million burns
patient
Most burn injuries occur in kitchen while cooking, in
bathroom, improper use of electrical appliances
Young children and elderly people are at
particularly high risk for burn injury
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An external burn injury comprises damage to the skin,
and there can be loss of skin and underlying tissues
with impairment of skin functions.
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The effects of a burn depend on its cause and extent
and the site of damage.
The serious burn injury is thought to be the most severe
trauma that is survivable
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Definition of Burns
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Loss of the continuity of the skin caused by thermal,
mechanical, electrical, atomic agents.
 or
“To damage or injure by fire, heat, radiation, electricity, or a
caustic agent“
 Or
Coagulative destruction of the skin and subcutaneous tissue.
 Or
Reaction of the body to some noxious agents which may be
thermal, electrical, chemical, irradiant or atomic which results
in tissue damage or death.
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Incidence of Burns – Gen stat….
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AETIOLOGY OF BURNS – According to
Causative agent
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THERMAL (WET HEAT & DRY HEAT): Hot water / Direct fire.
CHEMICAL BURNS: Such as acids and alkalis cause the
majority of chemical burn. The depth of burn is related to the
nature of compound and length of time it remains on the skin.
ELECTRICAL BURNS. Burns will appear on the skin where there
has been contact with a live wire. There will be a burn at the
entry and exit site of the electric current.
INHALATION BURNS. Direct thermal injury can be sustained
by inhalation of flames, hot gases or steam.
RADIATION: Sun light – UVR / IRR
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heat
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electricity
Chemical
materials
Radioactive
materials
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laser
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Mechanism/Type: Chemical Burn
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Mechanism/Type:Electrical Burn
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- direct contact with electrical current
 entry & exit wounds
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Typical burns from hot water in a child
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PREVENTION OF BURNS – A GENERAL
PERSPECTIVE
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It is essential to ensure that kettles and hot pans are
out of the reach of children.
Electrical sockets have shutters, and electrical cables
are secure with the insulation intact
Circuit breakers are in use with external appliances
Matches and cigarette lighters are stored safely
Smoke alarms should be fitted
The Health and Safety at Work Act 1974
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SKIN ANATOMY
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SKIN
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The skin, the largest organ of the body, consists of two
layers-the epidermis and dermis.
The epidermis is the outer layer that forms the
protective covering. It is Avascular.
The thicker or inner layer is the dermis which contains
blood vessels, hair follicles, nerve endings, sweat and
sebaceous glands. Dermis is divided in to Superficial
Papillary Dermis and deep Reticular Dermis.
When the dermis is destroyed, so are the nerve
endings that allow a person to feel pain, temperature,
and tactile sensation
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LAYERS OF SKIN
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FUNCTIONS OF SKIN
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The most important function of the skin is to act as
a barrier against infection.
The skin prevents loss of body fluids, thus
preventing dehydration.
The skin also regulates the body temperature by
controlling the amount of evaporation of fluids
from the sweat glands.
Skin helps in Vitamin D synthesis
The skin serves a sensory reception.
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Functions of the skin
Physical barrier
Vitamin D production
Immunity
Sensation
Identity
Temperature control
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CLASSIFICATION OF BURNS - according
to depth of burn
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Traditional Classification

1st degree

2nd degree
Alternative Classification
 Superficial
Partial Thickness
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3rd degree
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Superficial
Deep
Full thickness
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Classification According to Depth
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Depth of burn - Superficial (erythema)
Involves epidermis only:
•
Painful
•
Red
•
No blistering
•
Heals rapidly (reversible injury)
•
No permanent scars
Note that erythema is NOT included when
assessing TBSA
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Depth of Burn – superficial partial
thickness
Typical hot water scald
Involves epidermis and upper
dermis:
•
Red
•
Blistering, moist
•
Painful
•
Heals by epithelialization
•
Healing complete within 14 days
•
Minimal or no permanent scars
but can leave discolouration
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Patches of skin
that would come
off on cleaning
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Glistening moist
red/pink
appearance typical
of superficial injury
Depth of Burn - superficial partial
thickness
Pin-point
bleeding
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Blister
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Pink surface;
blanches on
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pressure
Depth of Burn – deep partial thickness
Involves epidermis, upper dermis and
varying degrees of lower dermis:
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•
Pale, mottled appearance
•
Fixed staining (no blanching)
•
May be painful or insensate
(depending on depth)
•
Heals by combination of
epithilialization and wound
contracture
•
May take weeks to heal
•
Can leave significant scars and
contractures over joints depending
on time taken to heal
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Deep dermal area, reddish
with fixed staining
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Depth of Burn – full thickness
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•
Involves all of epidermis and all of
dermis
•
Dry, leathery (white, dark brown or
charred)
•
Insensate
•
Heals by contraction
•
Delayed healing
•
Hypertrophic or keloid scars
•
Leads to contractures
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Dry, leathery, charred
appearance of a full
thickness burn
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Circumferential full thickness burn
Black, charred skin
Typical position of
hand in full thickness
burns with
metacarpophalangeal
joints extended and
interphalangeal joints
flexed
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Depth of Burn – mixed thickness
(A)
Assess the
depth of the
burn in areas
A, B and C
(B)
(C)
Depth of Burn – Mixed thickness
Full thickness,
dry white
leathery
appearance
Superficial partial
thickness showing
pink blanching
Deep dermal with pale pink and
white patches, non blanching
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Type[10]
Layers
involved
Appearance
Texture
Sensation
Healing Time
Prognosis
Heals
well;[10] Repeated sunbur
nsincrease the risk of skin
cancerlater in life[12]
Superficial
(Firstdegree)
Epidermis[5]
Red without
blisters[10]
Dry
Painful[10]
5–
10 days[10][11]
Superficial
partial
thickness
(Seconddegree)
Extends into
superficial
(papillary)der
mis[10]
Redness with
clear blister.
Blanches with
pressure.[10]
Moist[10]
Very
painful[10]
Local
less than 2–3
infection/cellulitis but no
weeks[6][10]
scarring typically[6]
Deep partial
thickness
(Seconddegree)
Extends into
deep
(reticular)
dermis[10]
Yellow or
white. Less
blanching.
May be
blistering.[10]
Fairly
dry[6]
Pressure
Scarring, contractures
and
3–8 weeks[10] (may require excision
discomfort[6
and skin grafting)[6]
]
Stiff and
Full thickness Extends
Prolonged
Scarring, contractures,
white/brown[10 Leathery[1
[10]
(Thirdthrough entire ]
Painless
(months) and amputation (early
0]
No
[10]
degree)
dermis
incomplete[10] excision recommended)[6]
blanching[6]
Extends
through entire
IV-degree
skin, and into Black; charred
(SUBDERMAL
Dry
underlying fat, with eschar
BURN)
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muscle and
bone[10]
Requires
Painless
excision[10]
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Amputation, significant
functional impairment
and, in some cases,
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death.[10]
Example
TEST FOR STUDENTS TO MENTION THE CLASSIFICATION TYPE OF BURNS
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Pathophysiology of Burn Injury
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Pathophysiology refers to the complex chain of mechanisms
that occur in the skin (local effects) and in other organ
systems (systemic effects) when a burn injury occurs, as well
as what happens as the skin regenerates and heals

Local Effects

Systematic Effects

Skin Regeneration and Scarring

Electrical Burns
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Zones of Burn Injury
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Zone of Coagulation
Inner Zone
 Area of cellular death (necrosis)
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Zone of Stasis
Area surrounding zone of coagulation
 Cellular injury: decreased blood flow & inflammation
 Potentially salvable; susceptible to additional injury
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Zone of Hyperemia
Peripheral area of burn
 Area of least cellular injury & increased blood flow
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 Complete recovery of this tissue
likely.
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Local Effects
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Local effects of burn injury (1)
Summary of local effects:
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Cell death/disturbed function
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Release of inflammatory mediators
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Increased capillary permeability
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Microvascular thrombosis
1. Cell death/disturbed function
Cellular function is disturbed when the temperature rises above 43oC. The higher the
temperature and more prolonged the contact, the more cells die. An instantaneous full
thickness burn occurs at a temperature of 700C or greater.
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Due to differences in skin
thickness with age, at 55C,
severe damage occurs after 10
seconds in a child and 30 seconds
in an adult. Skin thickness is also
reduced in older people and in
certain conditions (e.g. steroid
therapy).
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Local effects of burn injury (3)
3. Increased capillary permeability
When capillaries are damaged, they leak protein-rich
fluid which results in oedema.
Normal skin; normal
capillary permeability
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Burn wound oedema with
increased capillary permeability
and protein leakage
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Local effects of burn injury (4)
4. Microvascular Thrombosis
Release of thrombogenic factors such as thromboxane, together with
a hypovolaemic state cause sludging in the smallest blood vessels.
This in turn leads to further tissue ischaemia, increased cell death
and can cause extension of the depth and surface area of the burn.
Area of burn
increases due to
sludging in blood
vessels and
ischaemia
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Systemic effects of burn injury (2)
Psychological system
Respiratory system
Cardiovascular system
Immune system
Renal system
Gastrointestinal system
Haematological system
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Complications
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Hypertrophic scar =
continued production
of collagen
Keloid = ….with
extension into
surrounding tissues
Scar contracture
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The hypertrophic scar is defined as a widened or
unsightly scar that does not extend beyond the
original boundaries of the wound. Unlike keloids,
the hypertrophic scar reaches a certain size and
subsequently stabilizes or regresses.
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Keloid scars are defined as an abnormal scar that
grows beyond the boundary of the original site of
a skin injury. It is a raised and ill defined growth of
skin in the area of damaged skin.
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Burn Scars - Hypertrophic
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Burn Scars - Keloid
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Burn Scars - Contracture
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Burn Scars - Contracture
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