A burn is a wound in which there is coagulative necrosis of the tissue.

Types of burns;

● Ordinary burn caused by dry heat
● Scalds caused by moist heat
● Chemical burns caused by strong acid or base
● Electric burns
● Radiation burns
● Cold burns

The peculiarity of electric burns is that there is minimal destruction of the skin, which is involved only at the point of contact with source. The muscle, the nerve and blood offer least resistance to the electric current and so sustain maximum amount of tissue damage.

Radiation burns are caused by x rays or radium. Two types of radiodermatitis are usually seen.

* Acute radiodermatitis that usually develops on or about the 5th day

* Chronic radiodermatitis, the most important feature of which is its liability to grow in to cancers.

Cold burns include:

* Freezing injuries (frostbite)

* Non freezing cold injuries eg: chilblain

* Trench foot seen in soldiers

* Immersion foot occuring in shipwrecked persons.

Severity of burns:

The extent of burn is most commonly estimated by the “rule of nines”

The topical agents used during burn wound care include:

Silver nitrate : Although gram positive organisms are slightly less susceptible to it, true resistance does not occur. Its most serious disadvantages are the assosciated electrolyte disturbances.

Cerium nitrate: This is shown to be an effective topical antimicrobial agent and is currently undergoing clinical evaluation

Mafenide acetate: Only this agent is able to penetrate the eschar and is capable of suppressing bacterial proliferation beneath the eschar. It is particularly effective against clostridia and pseudomonas. Its main disadvantage is hyperchloraemia, which is compensated by an increase in ventilation and subsequent respiratory alkalosis.