Part 32

No. Their action differs slightly or greatly according to the case and individual. A change from one to another is often necessary.

#In what forms and strength are these remedies to be applied?#

Chrysarobin is applied in several ways: as an ointment, twenty to sixty grains to the ounce, rubbed in once or twice daily; this is the most rapid but least cleanly and eligible method. As a pigment, or paint, as in the following:--

Chrysarobini, ........................ j Acidi salicylici, .................... gr. xx Etheris, ............................. fj Ol. ricini, .......................... [minim]x Collodii, ............................ fvij. M.

Or it may be used in liquor gutta-perchæ (traumaticin), a drachm to the ounce. It may also be employed in chloroform, a drachm to the ounce; this is painted on, the chloroform evaporating, leaving a thin film of chrysarobin; over this is painted flexible collodion. If the patches are few and large, chrysarobin rubber-plaster may be used.

Chrysarobin is usually rapid in its effect, but it has certain disadvantages; it may cause an inflammation of the surrounding skin, and, if used near the eyes, may give rise to conjunctivitis. As a rule, it should not be employed about the head. Moreover, it stains the linen permanently and the skin temporarily.

Pyrogallol is valuable, and is employed in the same manner and strength as chrysarobin. In collodion it should at first not be used of greater strength than three to four per cent., as in this form pyrogallol sometimes acts with unexpected energy. It is less rapid than chrysarobin, but it rarely inflames the surrounding integument. It stains the linen a light brown, however, and is not to be used over an extensive surface for fear of absorption and toxic effect. Oxidized pyrogallic acid, a somewhat milder drug in its effect, has been highly commended, and has the alleged advantage of being free from toxic action.

Tar is, all things considered, the most important external remedy. It is comparatively slow in its action, but is useful in almost all cases. As employed usually it is prescribed in ointment form, either as the official tar ointment, full strength or weakened with lard or petrolatum. It may also be used as pix liquida, with equal part of alcohol. Or the tar oils, oil of cade (ol. cadini), and oil of birch (ol. rusci) may be employed, either as oily applications or incorporated with ointment or with alcohol. Liquor carbonis detergens, in ointment, one to three drachms to the ounce of simple cerate and lanolin is a mild tarry application which is often useful. In stubborn patches an occasional thorough rubbing with a mixture of equal parts of liquor carbonis detergens and Vleminckx's solution, followed by a mild ointment, sometimes proves of value. In whatsoever form tar is employed it should be thoroughly rubbed in, once or twice daily, the excess wiped off, and the parts then dusted with starch or similar powder.

Ammoniated mercury is applied in ointment form, twenty to sixty grains to the ounce. Compared to other remedies it is clean and free from staining, although, as a rule, not so uniformly efficacious. It is especially useful for application to the scalp and exposed parts. It should not be used over extensive surface for fear of absorption.

-Naphthol and resorcin are applied as ointments, thirty to sixty grains to the ounce, and as they are (especially the former) practically free from staining, may be used for exposed surfaces.

Gallacetophenone and aristol also act well in some cases, applied in five- to ten-per-cent. strength, as ointments.

In obstinate patches the x-ray may be resorted to, employing it with caution and in the same manner as in other diseases.

#Pityriasis Rosea.# (Synonym: Pityriasis Maculata et Circinata.)

#What do you understand by pityriasis rosea?#

Pityriasis rosea is a disease of a mildly inflammatory nature, characterized by discrete, and later frequently confluent, variously sized, slightly raised scaly macules of a pinkish to rosy-red, often salmon-tinged, color.

#Upon what part of the body is the eruption usually found?#

The trunk is the chief seat of the eruption, although not infrequently it is more or less general.

#Describe the symptoms of pityriasis rosea.#

The lesions, which appear rapidly or slowly, are but slightly elevated, somewhat scaly, usually rounded, except when several coalesce, when an irregularly outlined patch results. At first they are pale or bright pink or reddish, later a salmon tint (which is often characteristic) is noticed. The scaliness is bran-like or flaky, of a dirty gray color, and, as a rule, less marked in the central portion; it is never abundant. The skin is rarely thickened, the process being usually exceedingly superficial.

#What course does pityriasis rosea pursue?#

The eruption makes its appearance, as a rule, somewhat rapidly, usually attaining its full development in the course of one or two weeks, and then begins gradually to decline, the whole process occupying one or two months.

#To what is pityriasis rosea to be attributed?#

The cause is not known; it is variously considered as allied to seborrha (eczema seborrhoicum), as being of a vegetable-parasitic origin, and as a mildly inflammatory affection somewhat similar to psoriasis. It is not a frequent disease.

#How is pityriasis rosea distinguished from ringworm, psoriasis and the squamous syphiloderm?#

From ringworm, by its rapid appearance, its distribution, the number of patches, and, if necessary, by microscopic examination of the scrapings.

Psoriasis is a more inflammatory disease, is seen usually more abundantly upon the limbs, the scales are profuse and silvery, and the underlying skin is red and has a glazed look; moreover, psoriasis, as a rule, appears slowly and runs a chronic course.

The squamous syphiloderm differs in its history, distribution, and above all, by the presence of concomitant symptoms of syphilis, such as glandular enlargement, sore throat, mucous patches, rheumatic pains, and falling out of the hair.

#State the prognosis of pityriasis rosea.#