Part 36

#What is the character of eczema as regards the degree of inflammatory action?#

The inflammatory action may be acute, subacute or sluggish in character, and may be so from the start and 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.

#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 hyperæmia 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 the corium and even the subcutaneous tissue may share in the process.

#Do the cutaneous manifestations of the eruptive fevers bear resemblance to the erythematous type of eczema?#

Scarlatina and erysipelas may, to a slight extent, but the presence or absence of febrile and other constitutional symptoms will usually serve to differentiate.

#What common skin diseases resemble some phases of eczema?#

Psoriasis, seborrha, sycosis, scabies and ringworm.

#How would you exclude psoriasis in a suspected case of eczema (squamous eczema)?#

Psoriasis occurs in variously-sized, rounded, sharply-defined patches, usually scattered irregularly over the general surface, with special predilection for the elbows and knees. They are covered more or less abundantly with whitish, silvery or mother-of-pearl colored imbricated scales. The patches are always dry, and itching is, as a rule, slight, or may be entirely absent. Eczema, on the contrary, is often localized, appearing as one or more large, irregularly diffused patches; it merges imperceptibly into the sound skin, and there is often a history of characteristic serous or gummy oozing; the scaling is usually slight and itching almost invariably a prominent symptom.

#How would you exclude seborrha (eczema seborrhoicum) in a suspected case of eczema?#

Seborrha of the scalp is more commonly over the whole of that region and is relatively free from inflammatory symptoms; the scales are of a greasy character and the itching is usually slight or nil. On the other hand, in eczema of this region the parts are rarely invaded in their entirety; there may be at times the characteristic serous or gummy oozing; inflammatory symptoms are usually well-marked, the scales are dry and the itching is, as a rule, a prominent symptom. These same differences serve to differentiate the diseases in other regions.

#How does scabies differ from eczema?#