Pathologic is a catarrh of the superficial layers of the skin; the vessels of the papillary body are enlarged and surrounded by strong small-celled infiltration; the lymphatic fissures are distended; the cutis shows considerable cedematous hyperamia. Simultaneously there is a swelling of the rete Malpighii and a loosening of the epithelial cells which leads to the formation of vesicles. In chronic eczema there is a still stronger infiltration with new-formations of connective tissue.
Etiology.—Eczema may originate from the most various causes. In the nursing baby we observe in the first place disorders of nutrition. Nurslings' eczema is nearly always encountered in overfed anannie chil dren with abundant fat cushions, who suffer from gastric and intestinal disturbances, and in whom we have to assume that defective assimila tion is the cause of the eczema. The question whether there exists a difference in this respect in children fed on mother's milk and those artifically fed, is not yet determined with certainty. Judging by my own personal experience, I am inclined to believe. that artificially fed babies suffer much more frequently from eczema than breast-fed ones. Possibly the composition of the milk of wet-nurses may contain an excess of fat and have an influence on the nutrition of the child. In how far dentition plays a rele is as yet an undecided question.
Heredity also is unquestionably of some importance, for in some families nearly every child suffers from cezenta in its earliest infancy; iu the sante way scrofulosis and the lymphatic diastbesis — which Czerny treats collectively—are of undoubted importance in the etiology of eczema.
.Along with these considerations the state of the skin likewise claims attention. Both excessive dryness of the skin (xerodertnia) and an excessively fat condition of the skin (steatodermia) may ettuse a dis position for ITZ(.1111a. Again, amemic children who have been badly nursed and fed, are susceptible to At Calll`d ill the chapter on intertrigo to the great importance of the various seeretions and excretions in the development of eezenta. The secretions of the nose and conjunctiva, the stools, the urine and above all insufficient attention and want of cleanliness are the chief causes of intertrigo. At the same time. exterior causes, applica tion of medicaments, chemical irritation (see medication in exanthema) and thermic irritations (long-continued exposure to sun and heat) will no doubt exert an influence upon the skin. It has also been mentioned that in quite a number of derniat uses (scabies, prurigo, etc.) impetiginous nemenni may (teeny through the spreading of pus cocci.
Since IS91 l'inta has taken the position that eczema is of n parasitic natture, describing the affection as an infectious catarrh, and holding the so-called "Nlorococcus" responsible for the trouble. Likewise
Scholz, and after him Itaab, have pointed out the frequent presence of staphylococci with the idea of bringing thc illi0 an etiological conneetion with eczema. I myself, together with a large number of other authors, do not believe in the etiological influence of these cocci, although there is no doubt that for quite a series of infantile variations of eczema we are at a loss for an etiology, and in whieh we might well think of an infeetious cause (see Eczema myroticum and seborrhoicum).
Prognosis. -The prognosis of infantile eezetna is favorable so far as danger to life is concerned. Rut the question as to whether it is pos sit& in all cases to cure CeZeIlla ill 111.1114i tigs and other babies in a reason ably short time, is totally different. Indeed we are compelled to make t lie sorrowful admission that there are quite a number of infantile vczemas which oppose every external treatment. last COI' »1011i and then under go a spontaneous cure. Generally speaking, however. the great majmity of eczema:: of nurttlings and older children are curable, although fre quently an extraordinary amount of trouble and energy has to be ex pended on the part of both physieian and parents. lit recent times Fem. in a very interesting work points to the frequency of sodden death in eczema and simultaneously to the interesting fact that al autopsy nothing but status lymph:Atkin: was discovered. Feel. thinks that I he majority of 1,7,1111:1 CO111101101 t hi' status lymphaticus and really IxtIong to the series of fatal cases in that state.
Diagnosis.—The diagnosis of eczema may often be difficult, al though in the ease of nurslings and older children it is comparatively simpler than in adults. For purposes of differential diagnosis stress should always be laid upon the fact that eczema involves an entire arca, that for instance impetiginous eezema extends over a regional surface covered with impetiginous scabs, and that on the other hand impetigo itself is an infection consisting of various isolated foci. The same remarks apply to psoriasis, in which affection the single psoriatic spots can always he traced; they also apply to eczema seborrhoicum, which will be described later on. In favus either the yellow ocotillo inay be discerned or the atrophied cicatriceo. It is differentiated froin erythema by the inflammation which accompanies eczema; from ery sipelas, with which oedematous facial eczema may be easily vonfounded in the acute stage, by the febrile course. So-ealled miliaria differs from acute eczema by the superficiality of its appearance.