The paste-like ointment, referred to as useful in acute eczema, may also be used with a larger proportion (20 to 60 grains to the ounce) of salicylic acid.

The following, containing tar, may often be employed with advantage:--

[Rx] Ungt. picis liq., .................... [dram]j Ungt. zinci oxidi, ................... [dram]vij. M.

What is to be said in regard to the use of tarry applications?

Ointments or lotions containing tar should always be tried at first upon a limited surface, as occasionally skins are met with upon which this remedy acts as a more or less violent irritant. The coal tar lotion (liquor carbonis detergens) is the least likely to disagree and may be used as a mild ointment, one or two drachms to the ounce, or it may be diluted and used as a weak lotion as already referred to.

What external remedies are to be employed in eczema of a sluggish type?

The various remedies and combinations (mentioned above) useful in acute and subacute eczema may often be employed with benefit, but, as a rule, stronger applications are necessary, especially in the thick and leathery patches. The following are the most valuable:--

An ointment of calomel or ammoniated mercury; forty to sixty grains to the ounce.

Strong salicylic-acid ointment; a half to one drachm of salicylic acid to the ounce of lard.

Tar ointment, official strength; or the various tar oils, alone or with alcohol, as a lotion, or in ointment form.

Liquor picis alkalinus[B] is a valuable remedy in chronic _thickened_, _hard_ and _verrucous_ patches, but is a strong preparation and must be used with caution. It is applied diluted, one part with from eight to thirty-two parts of water; or in ointment, one or two drachms to the ounce. In such cases, also, the following is useful:--

[Rx] Saponis viridis, Picis liq., Alcoholis, .......... [=a][=a] ....... [dram]iij. M.

SIG. To be well rubbed in.

[Footnote B: [Rx] Pota.s.sae, ............................. [dram]j Picis liq., .......................... [dram]ij Aquae, ................................ [dram]v.

Dissolve the potash in the water, and gradually add to the tar in a mortar, with thorough stirring.]

In similar cases, also, the parts may be thoroughly washed or scrubbed with sapo viridis and hot water until somewhat tender, rinsed off, dried, and a mild ointment applied as a plaster.

Lactic acid, applied with one to ten or more parts of water is also of value in the sclerous and verrucous types. Caustic potash solutions, used cautiously, may also be occasionally employed to advantage in these cases.

Another remedy of value in these cases, as well as in others of more or less limited nature, is the _x_-ray. Exposures every few days, of short duration and 4 to 10 inches distance, with medium vacuum tube. This method has served me well in occasional cases; caution is necessary, and it should not be pushed further than the production of the mildest reaction. The repeated application of a high-frequency current, by means of the vacuum electrodes, is a safer and sometimes an equally beneficial method.

Is there any method of treating eczema with fixed dressings?

Several plans have been advised from time to time; some are costly, and some require too great attention to details, and are therefore impracticable for general employment. The following are those in more common use:--

The _gelatin dressing_, as originally ordered, is made by melting over a water-bath one part of gelatin in two parts of water--quickly painting it over the diseased area; it dries rapidly, and to prevent cracking glycerine is brushed over the surface. Or the glycerine may be incorporated with the gelatin and water in the following proportion: glycerine, one part; gelatin, four parts, and water eight parts.

Medicinal substances may be incorporated with the gelatin mixture.

A good formula is the following:--

[Rx] Gelatin, ............................. [Oz]j Zinci oxidi, ......................... [Oz]ss Glycerini, ........................... [Oz]iss Aquae, ................................ [Oz]ii-[Oz]iij.

This should be prepared over a water-bath, and two per cent. ichthyol added. A thin gauze bandage can be applied to the parts over which this dressing is painted, before it is completely dry; it makes a comfortable fixed dressing and may remain on several days.

_Plaster-mull_ and _gutta-percha plaster_. The plaster-mull, consisting of muslin incorporated with a layer of stiff ointment, and the gutta-percha plaster, consisting of muslin faced with a thin layer of India-rubber, the medication being spread upon the rubber coating.

_Rubber plasters._ These are medicated with the various drugs used in the external treatment of skin diseases, and are often of service in chronic patches.

Two new excipients for fixed dressings have recently been introduced--ba.s.sorin and plasment; the former is made from gum tragacanth, and the latter from Irish moss.

The following is a satisfactory formula for a tragacanth dressing:

[Rx] Tragacanth, .......................... gr. lxxv Glycerini, ........................... [minim] x.x.x Ac. carbolici, ....................... gr. x-xx Zinci oxidi, ......................... [dram]iss-[dram]iiss. M.

This is painted over the parts and allowed to dry, and a mild dusting powder sprinkled over. It cannot be used in warm weather or in folds, as it is apt to get sticky. The following is a ba.s.sorin paste which may be variously medicated.

[Rx] Ba.s.sorin, ............................ [dram]x Dextrin, ............................. [dram]vj Glycerini, ........................... [Oz]ij.

Aquae, ....................... q.s. ad. [Oz]iij.

It should be prepared cold.

Another "drying dressing" which may be used in cool weather is:

[Rx] Zinci oxidi, ......................... [Oz]j Glycerini, ........................... [Oz]ss Mucilag. acaciae, ..................... [Oz]ii-[Oz]iv.

It may be variously medicated.

The plaster-mull is used in all types, especially the acute; the gelatin dressing, and the gutta-percha plaster, in the subacute and chronic; and the rubber plaster in chronic, sluggish patches only. Acacia, tragacanth, ba.s.sorin and plasment applications are used in cases of a subacute and chronic character.

Prurigo.

Define prurigo.

Prurigo is a chronic, inflammatory disease, characterized by discrete, pin-head- to small pea-sized, solid, firmly-seated, slightly raised, pale-red papules, accompanied by itching and more or less general thickening of the affected skin.

Describe the symptoms and course of prurigo.

The disease first appears upon the tibial regions, and its earliest manifestation may be urticarial, but there soon develop the characteristic small, millet-seed-sized, or larger, firm elevations, which may be of the natural color of the skin or of a pinkish tinge. The lesions, whilst discrete, are in great numbers, and closely crowded. The overlying skin is dry, rough and harsh; itching is intense, and, as a result of the scratching, excoriations and blood crusts are commonly present. In consequence of the irritation, the inguinal glands are enlarged. Sooner or later the integument becomes considerably thickened, hard and rough. Eczematous symptoms may be superadded. In severe cases the entire extensor surfaces of the legs and arms, and in some instances the trunk also, are invaded. It is worse in the winter season.

What is known in regard to etiology and pathology?

It is a disease of the ill-fed and neglected, usually developing in early childhood, and persisting throughout life. It is extremely rare, even in its milder types, in this country. Clinically and pathologically it bears some resemblance to papular eczema.

Give the prognosis and treatment of prurigo.