The eruption is influenced by treatment. Bland astringent lotions or ointments are most serviceable. The fluid extract of grindelia robusta, two to four drachms to the pint of water, dabbed on frequently, or cloths wet with it kept constantly applied, will usually have a remarkably beneficial effect. Black wash, either alone or followed by the oxide-of-zinc ointment, as in acute eczema, and lead-water, are both serviceable. A saturated solution of sodium hyposulphite, a lotion of sodium bicarbonate, one of carbolic acid, one or two drachms to the pint of water, a weak ammonia lotion, and other applications of a similar nature, may also be advised, frequently with good result.
Other substances which at times act on the skin somewhat similarly to the rhus plants are the aniline dyes, mezereon, arnica, and certain other drugs, as savin, croton oil, tartar emetic, mercurials, etc.
DERMATITIS CALORICA.—Both heat and cold are capable of producing serious disturbances of the skin. The condition varies from a simple erythematous inflammation to a state of actual gangrene, depending upon the degree and duration of the cause, and to some extent upon the recuperative power of the exposed parts. Whether due to heat (dermatitis combustionis, combustio, burns) or to cold (dermatitis congelationis, congelatio, frost-bite, chilblain), the clinical symptoms are about the same. Treatment is generally of a soothing character.
In cases of dermatitis due to cold which are seen immediately after exposure, the parts should gradually be brought back to a normal temperature, at first being rubbed with snow or cold water applied. In ordinary chilblains stimulating applications are most serviceable, such as tincture of iodine and frictions with oil of turpentine. Balsam of Peru, camphor, lead plaster, carbolic acid, twenty to sixty grains to the ounce of ointment, camphor, and similar remedies may also be mentioned.
In burns where the inflammation is of a mild degree, sodium bicarbonate, either as a powder or in saturated solution, is effective; while in those of a more severe grade a solution of 2 to 5 per cent. will be of greater advantage. In burns or frost-bites in which the inflammation is vesicular, bullous, pustular, or escharotic the measures advisable in ordinary inflammation are to be employed.
DERMATITIS MEDICAMENTOSA.—Medicinal eruptions are due to the ingestion of certain drugs, some of which produce in a large proportion of individuals, sooner or later, well-defined cutaneous manifestations; on the other hand, many drugs are only exceptionally noted as giving rise to cutaneous disturbance. Of the former, the iodides and the bromides stand conspicuous; while of the latter class, arsenic and quinine may be cited. The glandular structures of the skin are frequently involved, especially in the iodide and bromide eruptions, and apparently the inflammation and resulting pustules are due to the effort at elimination through these structures. In other instances, especially the erythematous and urticarial eruptions, the effects of the drug seem to be due to some action upon the nervous system.
Arsenic.—Exceptionally eruptions are seen to follow the continued administration of arsenic. They are of an erythematous type, resembling the macular syphiloderm and measles; or papular, somewhat similar to the papular manifestation of erythema multiforme. Vesicles, herpetic in character, and pustules have also been observed. An urticarial-like eruption has occasionally been noted. In several instances arsenic has seemed to hold a causative relationship to an attack of herpes zoster. Arsenical dermatitis is most frequently seen about the face, neck, and hands, and lasts usually from a few days to two weeks. Workmen in arsenic-works are occasionally observed to have a pustular, ulcerative, and even gangrenous eruption, due to the local action of the drug.
Atropia or Belladonna.—A scarlatinoid rash is a frequent result of ingestion of belladonna, even a small dose at times sufficing to provoke the eruption. It is seen most frequently in children, face, neck, and chest being usually involved. Dryness of the throat and general malaise may be present. Usually there is no febrile disturbance, and desquamation seldom if ever follows, the rash usually passing away within a few hours or days after the drug has been discontinued.
Bromides.—The eruption from the bromides is usually pustular in type, occasionally furuncular, and at times giving rise to purulent accumulations of a carbuncular character. In some individuals a single dose suffices to call out the eruption; usually, however, it is only after a few weeks' administration that the cutaneous lesions are observed. In rare instances even its prolonged use is unaccompanied by any disturbance of the skin. The face, neck, shoulders, and back are most prone to its effects. The pustules have their seat in and about the sebaceous glands. A small dose of arsenic or bitartrate of potassium with each dose of the bromide will sometimes prevent the eruption caused by the latter.
Cannabis Indica.—An eruption of a vesico-papular type, the lesions pinpoint- to pea-sized, scattered over the entire surface, accompanied with considerable pruritus, has been recorded, following within twelve hours after a full dose of the drug, and disappearing in a few days.