Overview

A burn is any injury caused by external agents to the body’s surface, potentially destroying not only the skin but also deeper tissues such as muscles, bones, and organs.

Types and Causes

Burns can be classified as follows:

By depth:

1st degree: affects the epidermis (outermost layer of the skin). Presents with redness, no blisters, and slight local swelling. Pain is present
2nd degree: affects the epidermis and part of the dermis (second layer of the skin). Blisters are present and pain is intense
3rd degree: affects all layers of the skin, muscles, and bones. Skin necrosis (tissue death) occurs, appearing whitish or dark. Pain is absent due to the depth of the burn, which damages all nerve endings responsible for pain sensation

By extent:

The extent of a burn is represented as a percentage of the body surface area affected.

minor (or “small burn”): affects less than 10% of the body surface
moderate (or “medium burn”): affects 10% to 20% of the body surface
severe (or “major burn”): affects more than 20% of the body surface

Two rules can be used to estimate the extent of a burn:

Rule of nines: assigns a value of nine (or a multiple of nine) to each body segment:

head - 9%
front torso - 18%
back torso - 18%
upper limbs - 9% each
lower limbs - 18% each
genitals - 1%

Palm rule: generally, the palm of an individual’s hand represents 1% of their body surface area. Thus, the extent of a burn can be estimated by counting the “number of palms.”

Burns on the hands, feet, face, perineum, neck, and eyes—regardless of depth or extent—require hospital treatment. The severity of a burn is determined by its depth, extent, and the area affected.

Causes are classified as follows:

Physical agents

thermal: hot liquids, hot grease, hot irons, steam, and fire
electrical: low-voltage current (household appliances), high voltage, and lightning
radiant: result from exposure to sunlight or nuclear sources

Chemical agents

industrial chemicals, household products such as solvents, caustic soda, bleach, or any acid or alkali

Biological agents

living organisms, such as caterpillars, jellyfish, and nettles

Treatment

Thermal burns

Caused by hot liquids and objects, steam, and fire:

cool the burned area with cold water (do not use ice, as it may worsen the burn)
cover the area with a clean cloth
immediately remove rings, bracelets, watches, necklaces, belts, shoes, and clothing before the area begins to swell

Chemical burns

Caused by contact with chemical products such as acids:

rinse the area for at least 20 minutes under running water
immediately remove rings, bracelets, watches, necklaces, belts, shoes, and clothing before the area begins to swell
remove any contaminated clothing to prevent burns in other areas
if the eyes are affected, rinse thoroughly with running water until medical help is available. If wearing contact lenses, remove them immediately

Electrical burns

Caused by low-voltage current (e.g., household appliances), high voltage, and lightning:

do not touch the victim
turn off the electrical current
in all cases of burns, take the person to the nearest medical facility (emergency room or hospital)

What not to do

do not use: toothpaste, ointments, egg whites, butter, cooking oil, or any other substance on the burned area
do not remove stuck fabric: carefully cut and remove only what is loose
do not pop blisters

By Einstein Editorial Board