nd so continue throughout its whole
course; or it may, as is usually the case, vary in intensity from time
to time.

#State the character of eczema as regards duration.#

As a rule, it is a persistent disease, showing little, if any, tendency
to spontaneous disappearance.

#Is eczema influenced by the seasons?#

Yes. With comparatively few exceptions the disease is most common and
much worse in cold, windy, winter weather.

#To what may eczema be ascribed?#

Eczema may be due to constitutional or local causes, or to both. It may
be considered, in fact, as a reaction of the skin tissues against some
irritant, and the latter may have its origin from within or without.

#Name some of the important constitutional or predisposing causes.#

Gouty diathesis, rheumatic diathesis, disorders of the digestive tract,
general debility or lack of tone, an exhausted state of the nervous
system, dentition and struma.

#Is a constitutional cause sufficient to provoke an attack?#

Yes; but often the attack is brought about in those so predisposed by
some local or external irritant.

#Mention some of the external causes.#

Heat and cold, sharp, biting winds, excessive use of water, strong
soaps, vaccination, dyes and dyestuffs, chemical irritants, and the
like. There is a growing belief that some cases presenting eczematous
aspects are probably parasitic in origin. In fact, some observers hold
to the microbic view of all cases of eczema.

Contact with the rhus plants, while producing a peculiar dermatitis,
usually running an acute course terminating in recovery, may, in those
predisposed, provoke a veritable and persistent eczema. In fact, in our
examination as to causes in a given case, especially of the hands and face,
all possible exciting factors should be inquired into, such as the handling
of plants, chemicals, dyes, etc.

[Illustration: Fig. 24. Eczema of Face.]

#Is eczema contagious?#

No. The acceptance of a parasitic cause for the disease, however,
necessarily carries with it the possibility of contagiousness under
favoring conditions. Such is not supported, however, by practical
experience.

#What is the pathology?#

The process is an inflammatory one, characterized in all cases by
hyperaemia and exudation, varying in degree according to the intensity
and duration of the disease. The rete and papillary layer are especially
involved, although in severe and chronic cases the lower part of t