The rational indication is to get rid of the poisonous oil which may be on the skin as quickly as possible; the parts should be well washed, and scrubbed with soap and water, or alcohol. Fatty preparations, being oil solvents, if used, tend but to spread the evil. Pfaff (Jour. Exp. Med., Mar., '97).
Poisoning from the action of the Rims toxicodendron is differentiated from ec zema by the vesicles being much more numerous, swelling and cedema being greater, and exposed parts being more likely to be affected, particularly the inner surfaces of the fingers, while the eczematous eruption is more frequently polymorphous. Sun-burn sometimes re sembles dermatitis venenata, but it is more diffuse, and is usually localized en tirely to exposed parts, while rhus poisoning affects the breasts and geni talia also. Scabies is excluded by the history and by the absence of the Acarus scabiei. J. Sobel (Med. Rec., Nov. 5, '98).
Blastomycetic dermatitis is due solely to the invasion of the skin by one of the plant forms of the yeast family. In its clinical aspect it resembles lupus vul garis in the ulcerative stage. Hyde, Hektoen, and Bevan (Brit. Jour. of Derm., July, '99).
Treatment. —The most effective ap plications in the early stages of rhus poisoning are alkaline solutions, soap being especially useful on account of its detergent effect. By its early use, the greater portion of the poison can be removed, or its effects neutralized, be fore it has had time to penetrate the skin and act as an irritant. Solutions of bicarbonate of soda, 1 ounce to the pint, and black-wash usually relieve the itching promptly. Hardaway, of St. Louis, recommends very highly a lotion of zinc sulphate, 1/2 drachm to the pint of water. Fluid extract of grin delia robusta, either full strength or diluted with water in various propor tions, is highly lauded by Van Har lingen and others. When the vesicles have ruptured, drying or absorbent pow ders of starch, chalk, oxide of zinc, orris root, lycopodium, etc., may be used with good effect. Astringent lotions, among which acetate of lead holds a high place, are especially useful when the eruption is fully developed.
James C. White, of Boston, recom mends the following prescription:— Zinci oxidi, 5iv.
Ackli carbolici, 5j.
Aqum calcis, 0j.—M.
This should be applied freely and re peatedly over the affected parts. It alleviates the intense itching and hastens the involution of the inflammatory proc ess. Internal remedies are unnecessary and useless.
In the treatment of dermatitis ven enata, good results obtained with a modi fied "Burrow solution," containing 1 drachm of lead acetate and 3 drachms of alum to a quart of water. Picric acid, in a 1-per-ccnt. solution, is also useful. Salol in a 3-per-cent. solution is espe
cially good. J. Sobel (Med. Rec., Nov. 5, '98).
Remedy for dermatitis venenata upon which most reliance is personally placed is sodium hyposulphite, in the strength of 1/,„ ounce to 2 ounces dissolved in a pint of water. The affected part is mopped freely and frequently, or wrapped up in a cloth or bandage satu rated with the fluid, which is renewed as soon as the dressing has become dry. E. S. Gans (Med. Bull., Aug., '99).
Derma titis venenata, successfully treated by using locally a 10-per-cent. solution of ichthyol and a 1 to 5000 so lution of mercury bichloride; internally, a calomel purge followed by capsules of quinine, guaiacol carbonate, and phenace tin every four hours. J. A. Colnane (No. Amer. Jour. of Diag. and Pract., iii, 4, p. 13, 1900).
Arnica and Other Toxic Agents.—The tincture of arnica is so freely used as an external application to bruises and sprains that it may be useful to the practitioner to know that it sometimes produces a decided dermatitis, which may be accompanied by vesiculation.
The cessation of the application, and dressing the affected part with a ing or mildly-astringent lotion (bicar bonate of soda, borax, sulphate of zinc) will generally suffice to restore the nor mal condition of the part.
Among other agents used for medic inal purposes, which produce dermati tis of varying intensity, are mustard, cowhage, chrysarobin, ipecac, capsicum, mezereum, thapsia, cantharides, oil of turpentine, tar, creasote, paraffin, petro leum, pyrogallic and salicylic acids, chlo ral-hydrate, sulphur, iodine, mercurial preparations, and the more active alka line, acid, and mineral caustics.
The knowledge may also be useful that the juice of the common buttercup of the fields and the garden nasturtium may cause inflammation of the skin.
Dermatitis caused on four occasions by using iodoform in as many patients operated on. In the second instance the hand also had accidentally come into contact with the iodoform; this lead to dermatitis of the area thus exposed. On the two latter occasions the derma titis was accompanied by erysipelas, and led to prolonged pigmentation. This shows that no breach in the skin is re quired to produce this inflammation. Matschke (Tber. Monats., Oct., '93).
Case showing untoward effect of re sorcin applications: a single application sufficient to set up a violent dermatitis. R. W. Taylor (Jour. of Cut. and Genito Dis., Apr., '95).
[These artificial eruptions provoked by resorcin are relatively frequent, and this substance should only be used with much precaution, beginning with almost infinitesimal doses and suspending its use at the slightest sign of irritation. L. Baocg, Assoc. Ed., Annual, '96.]