BURNS AND SCALDS.
For all purposes of practice it is unnecessary to draw any distinction between a burn and a scald, for in reality none exists, except as regards the nature of the causative agent. In some cases requiring investigation, this may prove to be a matter of much importance.
Definition.—A burn is an injury produced by the application to the body of a heated substance, flame or radiant heat.
A scald is an injury produced by the application of a liquid at or near its boiling-point.
Appearances as Indicating Origin.
A hot body may produce a burn of any intensity, ranging between reddening of the skin and complete charring of the tissues, according as its temperature is elevated and the period of contact prolonged: the shape of the object and its size being indicated by the form of the burn. Metallic substances heated to a temperature of 100° C. (212° F.) are capable of producing redness and vesication and other injurious effects. At this temperature the albuminous elements of the blood and other fluids undergo coagulation. Some bodies require to be heated to redness, or nearly so, in order to produce a defined burn.
Very hot and partially-fused solids cause burns of greater severity than where the heated body is of a character favoring prompt removal. In such cases their adhesion to the skin involves the tearing away of the superficial portions of the derma in their removal, or they by their adherence prolong the contact of the heated body, thus intensifying their destructive action.
Metals in a state of fusion produce burns which cannot be easily distinguished from those caused by solid bodies. Such burns are classed as scalds. Their effects may vary in any degree between slight redness and complete destruction of the tissues with charring. Burns caused by melted solids are less regular in form and outline than those caused by heated solids. They are usually of greater severity on account of the high temperature to which they have been raised.[700]
Boiling Water.—Scalds by boiling water may be so slight as to produce redness only, or they may be so severe as to cause marked and characteristic symptoms. Those noted in severe cases are an ashy hue of the skin, accompanied by a soaked or sodden appearance and the production of blisters. Occasionally these features are not easily distinguished from those of burns from other sources. Blackening of the skin and charring of the tissues never result from burns by boiling water. As in all burns, a large surface involved renders an early fatal issue probable. In severe cases, not necessarily fatal, gangrene of the parts injured sometimes occurs. Most of those met with are accidental, yet cases of scalding by hot water with intent to injure are not uncommon, aside from injuries and death resulting from explosion of boilers, bursting of steam-pipes, etc. Occasional instances are recorded of death of children, the insane or feeble persons by inadvertent immersion in a bath of hot water (Case 21).
Severe and fatal burns of the mouth, fauces, and larynx in young children occur from inhaling steam or swallowing boiling water from a teapot or kettle in an attempt to drink (Case 5).
Burns by burning oil produce effects and appearances similar to those by melted metals.
Burns by flame are specially characterized by scorching of the surface. Hairs upon the part actually burned are scorched and usually also those in the vicinity of the burned patches. Such conditions could not result from scalds by hot water, boiling oil, or from a hot body only.
Burns by petroleum or its derivatives resemble the burns from flame, except that the injured portions of the body are not only scorched but blackened and are usually burned more severely than by flame alone, as the clothing holds the burning substance in contact with the parts. The odor of the agent is also very noticeable.
Burns by Acids and Corrosive Agents.—The injury produced by a mineral acid, the caustic alkalies, etc., has frequently been the source of judicial inquiry. “Vitriol-throwing,” as it has been termed, has been and occasionally is resorted to with malicious intent to injure. No case of death resulting directly and solely from this cause is recorded, but grave injuries, involving loss of sight, etc., have resulted. A case is referred to by Taylor[701] where sulphuric acid was poured into the ear of a woman while asleep by her husband. Death ensued, after six weeks, from disease of the brain resulting indirectly from the use of the acid.
The appearances of a burn by a mineral acid are distinguished from heat burns with little difficulty. The eschar which results is not dry and leathery, as in a burn by heat, but soft and readily sloughing away. There is no redness around the site of the injury, the color of the burn being uniform, and no blisters are formed. There is no blackening of the skin and the hairs are not scorched. The color of the skin around the injured portion may afford valuable evidence of the nature of the agent employed. Nitric acid produces a yellow stain, sulphuric acid a dark brown, and chlorohydric acid a brownish-yellow stain.[702] The clothing also is capable of affording characteristic evidence by the discolorations produced; and the destructive agent employed may be determined by a chemical analysis of the fabric.[703]
It is not possible to distinguish a post-mortem from an ante-mortem burn by an acid when no vital reaction has taken place.