results--_acne pustulosa_; the pustule, in some cases, may
have a markedly inflammatory and hard base--_acne indurata_; and not
infrequently the lesions in disappearing may leave a pit-like atrophy or
depression--_acne atrophica_; or, on the contrary, connective-tissue new
growth may follow their disappearance--_acne hypertrophica_; and, in
strumous or cachectic individuals, the lesions may be more or less
furuncular in type, often of the nature of dermic abscesses, usually of
a cold or sluggish character, and of more general distribution--_acne
cachecticorum_.

#What is acne artificialis?#

Acne artificialis is a term applied to an acne or acne-like eruption
produced by the ingestion of certain drugs, as the bromides and iodides,
and by the external use of tar; this is also called _tar acne_.

#What course does acne pursue?#

Essentially chronic. The individual lesions usually run their course in
several days or one or two weeks, but new lesions continue to appear
from time to time, and the disease thus persists, with more or less
variation, for months or years. In many cases there is, toward the age
of twenty-five or thirty, a tendency to spontaneous disappearance of the
disease.

[Illustration: Acne.]

#Is the eruption in acne usually abundant?#

It varies in different cases and at different periods in the same case.
In some instances, not more than five or ten papules and pustules are
present at one time; in others they may be numerous. Not infrequently
several lesions make their appearance, gradually run their course, and
the face continues free for days or one or two weeks.

#Does the eruption in acne disappear without leaving a trace?#

In many instances no permanent trace remains, but in others slight or
conspicuous scarring is left to mark the site of the lesions.

#Are there any subjective symptoms in acne?#

As a rule, not; but markedly inflammatory lesions are painful.

#State the immediate or direct cause of an acne lesion.#

Hypersecretion or retention of sebaceous matter. Recent investigations
point to the possibility of a special bacillus being the exciting cause,
in some instances at least. The pyogenic cocci are added factors in the
pustular and furuncular cases.

#Name the indirect or predisposing causes of acne.#

Digestive disturbance, constipation, menstrual irregularities,
chlorosis, general debility, lack of tone in the muscular fibres of the
skin, scrofulosis; and