The urticaria or roseola is no longer a simple redness of the skin, assuming a livid hue as it dies away : but it has a tendency to desquamation—it becomes brown instead of purple. The lichen is larger and discolored, and has a more decided scab on its top ; it approaches more nearly to the characters of psoriasis. The squamous affection again is much less scaly and more tuber cular ; the desquamating cuticle does not cover the entire surface ; it is thin and subordinat,e. The form resembling tubercle does not present a smooth elevation, which gradually subsides into the tumid skin around ; but it is prominent, covered with scales or crusts, and is scattered over the body in place of being aggre gated together.
In the pustular eruptions the analogies are closer, but still the • characters are defined. If resembling impetigo, it forms a well marked ring, the suppuration penetrates deeper, and the skin around is consequently elevated. If it seem more like ecthyma, we shall have a difficulty in saying that it is not rupia; the skin is deeply ulcerated, and a thick crust forms on its surface ; its circumference is round, and its edges high; while in its commence ment there is neither the bright redness nor the occasional mixture of blood with the pus, which is common in ecthyma. When the disease assumes these suppurative forms, ulceration of the angle of the lips is not uncommon, and greatly confirms the diagnosis. Its discrimination from rupia is less important, because the same treatment which is called for in the one is equally suitable to the other ; but it is less frequently like true rupia than intermediate between that and ecthyma.
Coincident with any of the foregoing eruptions, especially when their character is pustular, we sometimes find deep burrowing ulcers on the face, and at the alto of the nose, resembling lupus, or there may be ortona from commencing disease of the bones bf the nose, with soreness of its lining membrane.
Congenital syphilis is chiefly marked by ulcers at the angles of the mouth, cracked lips, running of the nose, "snuffles," condylo mats, and ulceration of the anus and pudendum, with emaciation.
In reference to the copper color of syphilitic eruptions, a few words may be added on the subject of cutaneous discoloration generally. As an objective phenomenon it forms the direct exponent of purpura and of jaundice, and is the chief feature of anaemia and chlorosis : it helps us to distinguish measles from scarlatina, and it materially aids our diagnosis of cancer, and of disease of the heart and kidneys.
In other cases the change of color is more distinctly confined to the skin itself, as when, for example, a dusky gray or blue color is produced by the internal use of nitrate of silver. In some persons the existence of any simple
cutaneous disease, e. g., herpes, or lepra, is always followed on its decline by a brown stain, which lasts long after the skin has acquired its natural condition in all other respects, and this is particularly the case with persons of a dark complexion: it is the very same change as is seen after syphilitic affections, except that the color in the latter may be much darker, and commonly lasts for a longer period. In others, again, patches of a brown or yellowish color are seen, which have been called ephelides, from their supposed connection with sun-burning : they are very like syphilitic stains, except that they are scarcely so dark, and they have not been preceded by any other eruption. In their corn filen cement they resemble pityriasis versicolor, except in the absence of branny scales and roughness. They begin with small spots like freckles, which gradually enlarge and coalesce, forming large maculae which have not the cir cular form which pityriasis presents.
In what is called bronzed skin, the whole body becomes gradually of a brown color, sometimes variegated here and there by portions of natural color. This condition has been thought of late years to be perhaps connected with disease of the supra-renal capsules.
We need not allude to the congenital peculiarities of ntevi, or the freckles of early life : neither does the deficiency of color in the albino belong to con ditions of disease. Occasionally white spots are developed in advanced years, especially on the scrotum of old men known as vitiltgo, the true nature of which is as yet not understood. It does not seem connected with disease properly so called.
§ 10. Lupus and Scrofulous Ulceration.—Though generally re garded as belonging to the domain of surgery, these diseases are evidently of constitutional origin, and their characteristics ought at least to be known to the physician. There seems reason to believe that they belong to the same diathesis, and are chiefly modified by the age of the patient. They are marked by the same general feature of indolence and unwillingness to heal, by the inefficiency of local treatment, and by their being both modi fied by the same internal remedies. Lupus is more distinctly cutaneous ; it is superficial, and shows a great tendency to spread. Scrofulous ulcer is always preceded by abscess, and can only be regarded in a secondary sense as a disease of the skin.