scaly patches, and by
the history and course of the individual lesions.

#In what respects does the papulo-squamous syphiloderm differ from
psoriasis?#

The scales of the squamous syphilide are usually dirty gray in color and
more or less scanty; the patches are coppery in hue, and usually several
or more characteristic scaleless, infiltrated papules are to be found.
The face, palms, and soles are often the seat of the syphilitic
eruption; and, moreover, _concomitant symptoms of syphilis_, such as
sore throat, mucous patches, glandular enlargement, rheumatic pains,
falling out of the hair, together with the history of the initial
lesion, are one, several, or all usually present.

#How does seborrh[oe]a differ from psoriasis?#

Seborrh[oe]a of the scalp is usually diffused, with but little redness
and no infiltration; moreover, the scales of seborrh[oe]a are greasy,
dirty gray or brownish, while those of psoriasis are dry and comonly
whitish or mother-of-pearl colored. Psoriasis of the scalp rarely exists
independently of other patches elsewhere on the general surface.

That variety of seborrh[oe]a, commonly known as eczema seborrhoicum,
presents at times, both on scalp and general surface, a strong
resemblance to psoriasis, but the character of the scales and
distribution of psoriasis, as above stated, are distinguishing points;
seborrh[oe]a, moreover, favors hairy surfaces and in extensive examples
the scalp, eyebrows, sternal, and pubic regions rarely escape.

#How does psoriasis differ from ringworm?#

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