of excessive heat or cold,
to caustics and other chemical irritants, and to the ingestion of
certain drugs.

#What several varieties are commonly described?#

Dermatitis traumatica, dermatitis calorica, dermatitis venenata, and
dermatitis medicamentosa.

#Describe dermatitis traumatica.#

Under this head are included all forms of cutaneous inflammation due to
traumatism. To the dermatologist the most common met with is that
produced by the various animal parasites and from continued scratching;
in such, if the cause has been long-continued and persistent, a variable
degree of inflammatory thickening of the skin and pigmentation result,
the latter not infrequently being more or less permanent. The
inflammation due to tight-fitting garments, bandages, to constant
pressure (as bed-sores), etc., also illustrates this class.

#What is the treatment of dermatitis traumatica?#

Removal of the cause, and, if necessary, the application of soothing
ointments or lotions; in bed-sores, soap plaster, plain or with one to
five per cent. of ichthyol.

#What is dermatitis calorica?#

Cutaneous inflammation, varying from a slight erythematous to a
gangrenous character, produced by excessive heat (_dermatitis
ambustionis_, _burns_) or cold (_dermatitis congelationis_,
_frostbite_).

#Give the treatment of dermatitis calorica.#

In burns, if of a mild degree, the application of sodium bicarbonate, as
a powder or saturated solution, is useful; in the more severe grade, a
two- to five-per-cent. solution will probably be found of greater
advantage. Other soothing applications may also be employed. In recent
years a one-per-cent. solution of picric acid has been commended for the
slighter burns of limited extent. Upon the whole, there is nothing yet
so generally useful and soothing in these cases as the so-called Carron
oil; in some cases more valuable with 1/2 to 1 minim of carbolic acid
added to each ounce.

In frostbite, seen immediately after exposure, the parts are to be
brought gradually back to a normal temperature, at first by rubbing with
snow or applying cold water. Subsequently, in ordinary chilblains,
stimulating applications, such as oil of turpentine, balsam of Peru,
tincture of iodine, ichthyol, and strongly carbolized ointments are of
most benefit. If the frostbite is of a vesicular, pustular, bullous, or
escharotic character, the treatment consists in the application of
soothing remedies, such as are