Another formula, more especially useful in eczema of the hands and legs, is the following:--
[Rx] Ac. salicylici, ...................... gr. xxx Emp. plumbi, Emp. saponis, Petrolati, ...... [=a][=a] ........... [Oz]j. M.
(This is to be applied as a plaster, spread on strips of lint, and changed every twelve or twenty-four hours.)
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.
[Footnote B: [Rx] Potassæ, ............................. [dram]j Picis liq., .......................... [dram]ij Aquæ, ................................ [dram]v.