isease
exist: one of these regards it as parasitic, and the other considers it
to be trophoneurotic. Doubtless both are right, as a study of the
literature would indicate that there are, as regards etiology, really
two varieties--the contagious and the non-contagious. In America
examples of the contagious variety are uncommon.

#Does the skin undergo any alterative or destructive changes?#

Microscopical examination of the skin of the diseased area shows little
or no alteration in its structure beyond slight thinning.

#How do you distinguish alopecia areata from ringworm?#

The plaques of alopecia areata are smooth, often completely devoid of
hair, and free from scales; while those of ringworm show numerous broken
hairs and stumps, desquamation, and usually symptoms of mild
inflammatory action. In doubtful cases recourse should be had to the
microscope.

#What is the prognosis in alopecia areata?#

The disease is often rebellious, but in children and young adults the
prognosis is almost invariably favorable, permanent loss of hair being
uncommon. The same holds true, but to a much less extent, with the
disease as occurring in those of more advanced age. In extensive
cases--those in which the hair of the entire scalp finally entirely
disappears, and sometimes involves all hairy parts--the prognosis is
unfavorable. Only exceptionally does recovery ensue in such instances.

The uncertain duration, however, must be borne in mind; months, and in
some instances several years, may elapse before complete restoration of
hair takes place. Relapses are not uncommon.

#How is alopecia areata treated?#

By both constitutional and local measures, the former having in view the
invigoration of the nervous system, and the latter a stimulating and
parasiticidal action of the affected areas.

#Give the constitutional treatment.#

Arsenic is perhaps the most valuable remedy, while quinine, nux vomica,
pilocarpine, cod-liver oil and ferruginous tonics may, in suitable
cases, often be administered with benefit.

#Name several remedies or combinations employed in the external treatment
of alopecia areata.#

Ointments of tar and sulphur of varying strength; the various mercurial
ointments; the tar oils, either pure or with alcohol; stimulating
lotions, containing varying proportions, singly or in combination, of
tincture of capsicum, tincture of cantharides, aqua ammoniae, and oil of
turpentine. The following is a