Part 31

By its greater scaliness, by its higher degree of inflammatory action, and by its larger number of patches, as also by its history. In ringworm all the patches tend to clear up in the centre; in psoriasis this is rarely, if ever, so. If there is still any doubt, microscopic examination of the scrapings will determine.

#Give the prognosis of psoriasis.#

The prognosis is usually favorable, so far as concerns the immediate eruption, but as to recurrences, nothing positive can be stated. In rare instances, however, the cure remains permanent.

#How is psoriasis treated?#

Both constitutional and local remedies are demanded in most cases.

#Do dietary measures exert any influence?#

As a rule, no; but the food should be plain, and an excess of meat avoided.

#Name the important constitutional remedies usually employed in psoriasis.#

Arsenic is of first importance. It is not suitable in acute or markedly inflammatory types; but is most useful in the sluggish, chronic forms of the disease. The dose should never be pushed beyond slight physiological action. It may be given as arsenious acid in pill form, one-fiftieth to one-tenth of a grain three times daily, or as Fowler's solution, three to ten minims at a dose.

Alkalies, of which liquor potassæ is the most eligible. It is to be given in ten to twenty minim doses, largely diluted. It is valuable in robust, plethoric, rheumatic or gouty individuals with psoriasis of an acute or markedly inflammatory type; it is not to be given to debilitated or anæmic subjects.

Salicin, sodium salicylate, and salophen in moderately full doses act well in some cases. Occasionally thyroid preparations have a good effect.

Potassium Iodide, in doses of thirty to one hundred grains, t.d., acts favorably in some instances; there are no special indications pointing toward its selection, unless it be the existence of a gouty or rheumatic diathesis.

Oil of copaiba, potassium acetate, oil of turpentine, oil of juniper, and other diuretics are valuable in some instances, and, while often failing, sometimes exert a rapid influence, especially in those cases in which the disease is extensive and inflammatory. Wine of antimony, given cautiously, is also sometimes of service in the acute inflammatory type in robust subjects.

#Are such remedies as iron, quinine, nux vomica and cod-liver oil ever useful in psoriasis?#

Yes. In debilitated subjects the administration of such remedies is at times attended with improvement in the cutaneous eruption.

#What are the indications as regards the external measures?#

Removal of the scales, and the use of soothing or stimulating applications, according to the individual case.

#How are the scales removed?#

In ordinary cases, either by warm, plain, or alkaline baths, or hot-water-and-soap washings; in those cases in which the scaling is abundant and adherent, washing with sapo viridis and hot water may be required. Baths of sal ammoniac, two to six ounces to the bath are also valuable in removing the scaliness. The tincture of green soap (tinctura saponis viridis) is especially valuable for cleansing purposes in psoriasis of the scalp. The hot vapor bath once or twice weekly is serviceable in keeping the scaliness in abeyance, and has, moreover, in some cases, a therapeutic value.

The frequency of the baths or washings will depend upon the rapidity with which the scales are reproduced.

#Are soothing applications often demanded in psoriasis?#

In exceptional cases; in those in which the disease is acute, markedly inflammatory and rapidly progressing, mild, soothing applications must be temporarily employed, such as plain or bran baths, with the use of some bland oil or ointment. As a rule, however, the conditions, when coming under observation, are such as to permit of stimulating applications from the start. The most efficient soothing applications are the mild lotions and ointments employed in eczema of acute type.

#How are the stimulating remedies employed in psoriasis applied?#

As ointments, oils, and paints (pigmenta).

An ointment, if employed, is to be thoroughly rubbed in the diseased areas once or twice daily. The same may be said of the oily applications. The paints (medicated collodion and gutta-percha solution) are applied with a brush, once daily, or every second or third day, depending mainly upon the length of time the film remains intact and adherent.

#Name the several important external remedies.#

Chrysarobin, pyrogallol, tar, ammoniated mercury, -naphthol, and resorcin.

#Are these several external remedies equally serviceable in all cases?#