American Materia Medica, Therapeutics and Pharmacognosy

Physiological Action—Mustard is emetic, stimulant and actively
revulsive with marked anodyne properties. Its application to the skin
produces intense burning, violent inflammation, and if persisted in too
long, sloughing or ulceration. Taken into the stomach in large
quantities, if emesis be not produced, it causes a burning sensation and
a mild form of gastritis.
Specific Symptomatology—For external application it is indicated in
acute cutting pain local in character, usually intermittent and usually
present as the result of rapidly developing acute inflammation, but dull,
steady and constant pains or soreness, slowly developing and persistent,
are not readily relieved by its application. Turpentine externally is of
service in these cases.
Internally it is indicated to excite vomiting when non-corrosive poisons
have been taken, when a foreign body is lodged in the esophagus, or
when there is great distress from an overloaded stomach.
Administration—In the use of mustard for counter-irritation, in cases of
acute pain, it is desirable to obtain its sharp effects as quickly as possible.
In order to do this, a fresh article should be procured, one in which the
pungency is sharply indicated by its action on the nostrils and eyes,
since mustard kept in a paper package on the shelves for weeks is inert
from loss of the volatile oil. Vesication must be avoided, as the blisters
thus caused are of no advantage, and exceedingly painful and difficult to
heal. The white of an egg rubbed up with mustard and a little water, will
produce a poultice which will not readily blister.
When mild counter-irritation only is desired, which is to be prolonged for
some hours, a poultice is made in the proportion of one part of mustard to
four or six of linseed meal or flour. This is not, however, effective in acute
pain, but only where there is soreness or prolonged distress. Vinegar and
mustard also make a good poultice for prolonged use, as vinegar destroys
an excess of activity of the mustard.
For a hot mustard pediluvium, a tablespoonful of the powder is stirred into
a gallon or two of hot water, in which the feet are immediately im. mersed.
For a general mustard bath, two or three tablespoonfuls of mustard are
mixed in a full bath. For a child one tablespoonful will be sufficient, care
being taken to protect the eyes of the patient from the vapor.
Ellingwood’s American Materia Medica, Therapeutics and Pharmacognosy - Page 404