area, and after attaining variable size remain
stationary; or they may progress and coalesce, and in this manner sooner
or later involve considerable surface. The patches are sharply defined
against the sound skin by an elevated border, while the central portion
is somewhat depressed and usually atrophic. More or less thickening and
infiltration are observed. _There is no tendency to ulceration_. The
scaliness is, as a rule, scanty. The gland-ducts are enlarged, patulous
or plugged with sebaceous and epithelial matter.

The subjective symptoms of burning and itching are usually slight and
often wanting.

#What course does lupus erythematosus pursue?#

As a rule, the disease is persistent, although somewhat variable. At
times the patches retrogress, involution taking place with or without
slight sieve-like atrophy or scarring.

#State the causes of lupus erythematosus.#

The etiology is obscure. Some observers believe it to be a variety of
cutaneous tuberculosis. It is essentially a disease of adult and middle
age; is more common in women, and more frequent in those having a
tendency to disorders of the sebaceous glands. It may, in fact, begin as
a seborrh[oe]a.

#What is the pathology?#

It was formerly considered a new growth, but recent opinion tends toward
regarding it as a chronic inflammation of the cutis, superinducing
degenerative and atrophic changes. Variable [oe]dema of the prickle
layer and of the cutis is found. There is no tendency to pus formation.

[Illustration: Fig. 42. Lupus Erythematosus.]

#Is there any difficulty in the diagnosis of lupus erythematosus?#

As a rule, not, as the features of the disease--the sharply
circumscribed outline, the reddish or violaceous color, the elevated
border, the tendency to central depression and atrophy, the plugged up
or patulous sebaceous ducts, the adherent grayish or yellowish scales,
together with the region attacked (usually the nose and cheeks)--are
characteristic.

#State the prognosis of lupus erythematosus.#

The disease is often capricious and extremely rebellious to treatment;
some cases, up to a certain point at least, yield readily, and
occasionally a tendency to spontaneous disappearance is observed; a
complete cure is, however, it must be confessed, rather rare. The
disease in nowise compromises the general health. In those rare
instances of generalized disease the patient has usually died from an
intercurrent tuberculosis.