§ 91. Exanthematic Fevers.

A few short remarks on cutaneous eruptions generally:

An exanthem is an inflammatory process of the various layers of the skin, in consequence of which the colour and form of the skin change. These alterations of the skin are quite different from those occasioned by mechanical causes, injuries, burns, vesica-tories, sinapisms, etc. An eruption has to be treated differently, according as it is seated in one or the other layer of the skin. This observation applies particularly to old eruptions, the successful treatment of which requires that their primitive form should be correctly ascertained.

Eruptions may be classed under the following heads:

(a.) Maculosa, spots without elevation of the epidermis, smooth, and only distinguished here and there from the remainder of the skin by an increased redness, as in scarlatina, petechiae, lentigines.

(b.) Papulosa, pimples, slight elevations on the epidermis, without pustule, as in purpura miliaris, morbili, rubeola, miliaria, essera, verruca.

(c.) Pustulosa, elevations of the epidermis which are either empty or filled with a fluid, lymph or pus, as in variola, varicella, pemphigus, scabies.

(d.) Crustacea, with dry crusts, as in dry herpes, tinea, serpigo. 1