by Julius H. Hess, M.D.
Besides asphyxia and hypothermia there is a tendency to edema in small premature infants. This occurs, sometimes during birth, but more frequently during the first days of life, as edema of the extremities and genitalia. In contradistinction to the general view that these edemas and scleredema are to be regarded as sequelae of subnormal temperature, it must be emphasized that these edematous conditions are not uncommon in small prematures, and that they may occur even in utero. In this connection attention may be called to congenital general dropsy and to other localized edemas, that have been observed by others in premature infants immediately after birth, or in the new born. (Ballantyne, Link, Kirk, Oswald, Chiari.)
Special forms of edema are scleredema and sclerema. It is not always possible to make sharp differentiations between these and other forms of edema. Scleredema is designated that form of edema in which the skin is hard and taut, while sclerema is that condition in which the skin is hard and dried out. Many authors emphasize that in an individual case the sclerema is not to be distinguished from scleredema, since they are only quantitative differences of the same process. Ylppö  believes that it depends entirely upon the water richness of the tissues, whether the skin feels pasty hard (scleredema) or wooden hard (sclerema).
Etiology. -- As far as etiology is concerned we cannot make special differences. According to experience, the skin upon the external portion of the thigh, whenever edema of the feet is present, feels always somewhat tougher and harder (scleredemic), in comparison to soft edema of the genital region or of the inner surface of the thigh and leg. Because these differences in consistency are demonstrable in many premature infants a few hours after birth, we have to consider special anatomical conditions as factors responsible for their production. The younger the infant, the thinner is the fatty cushion. On the external surface of the thigh it is several millimeters thick even in the smallest prematures, while in other regions the subcutaneous fatty tissue is not well developed. The occurrence of hard edema on the external surface of the thigh with simultaneous occurrence of soft edema in other portions, forces upon us the conclusion that besides the water richness it also depends upon the richness of the subcutaneous fatty tissue, whether or not an edematous portion of the skin feels somewhat harder.
Now, new-born infants, and also prematures, whose bodies are especially rich in water, lose in weight during the first days of life, and thus it is easy to understand that the water content of the skin and of the subcutaneous fatty tissues gradually becomes less. According to Langer  and Knoepfelmacher , the subcutaneous fat contains chiefly palmitic and stearic acids, and proportionately only a small quantity of oleic acid. The fat of the new-born infant is therefore even with ordinary body temperature somewhat harder than the fat of the adult, which is rich in oleic acid. The usual very high water content of the fatty tissue in the new-born infant makes it of normal softness during ordinary temperature. It is easy to understand that the oleic-acid-poor, fatty tissue begins to feel hard when the water disappears from the interstitial spaces of the fatty tissue.
Symptoms. -- In small prematures that are observed carefully after birth, we may notice that the legs, and especially the feet and hands, may begin to swell in five to seven hours after birth. These swellings often occur no matter whether the infant is transferred immediately after birth into a warming tub, or whether it shows subnormal temperature. In infants with subnormal temperature edema occurs more frequently and is more marked. If the child is put into a somewhat inclined position, so that the hands and legs hang down, then very soon cyanotic swelling may be observed in the dependent extremities. If we change the position and allow the head to be lower than the legs then the edema disappears in a few hours.
This simple experiment shows that the cause of the edema occurring in the premature infant during the first days or hours of life, may be looked for in circulatory weakness. Besides this, the high water content of the tissues and the ready permeability of the blood and lymph vessels in prematures is of great importance in this respect. In these infants edema occurs not only in the skin, or more properly in the subcutaneous tissues, but also in many other tissues. The marked tendency to hydrops of the cavities and the high-grade edematous swellings of the pelvic walls and brain coverings is also a manifestation of this general property of the body of the premature infant. It cannot be denied, of course, that hypothermia and initial cooling of the premature infant are of importance in the development of edema. If the cold easily damages the small capillaries of an adult it does it even more easily in the premature infant, in whom the skin is rich in water. The water evaporation, by producing heat loss, favors the development of lesions of the capillaries. It is a mistake, however, to designate edema in premature infants simply as a sequel of hypothermia.
Treatment. -- In the treatment of sclerema it is important to see first that the water intake is increased. It is understood that proper care must be taken of the temperature and other conditions. In general, the prognosis in sclerema of the premature infant is not as bad as has generally been supposed. If we succeed in preventing early the marked desiccation of the infant, then it is still possible to save the infant.
Among the various forms of congenital dropsy, in which the infants are often prematurely born, erythroblastosis, first described by Schridde  and named by Rautmann , is the least understood. Congenital generalized edema may be the result of cardiac anomalies and diseases, portal obstruction, syphilis of the liver, fetal peritonitis, abnormality of the D. venosus Arantii, deformities of the intestines and diseases of the kidneys. Schridde, in 1910, pointed out a form of congenital general dropsy with hydramnios associated with a pathological blood state.
The disorder is characterized by anasarca and fluid in the cavities, hydramnios and enlargement of the liver and spleen. The latter two organs show the most marked changes, which consist of the accumulation, both inside and outside of the blood vessels, of large numbers of erythroblasts and a smaller number of other marrow cells. The lymph follicles in the spleen are absent and the liver cells are crowded out. Accumulations of lymphoblasts in small numbers may be found in the kidneys, adrenals, and lymph glands. Erythroblasts appear in the blood in greatly increased numbers and they show very often mitotic processes. The heart is often hypertrophied.
Because of the presence of hemosiderin in the spleen and liver, Schridde was led to believe that the disease was due to a severe anemia with compensatory hematopoiesis having no relation to syphilis. Others have assumed that the extramedullary formation of blood corpuscles was due to some form of unknown toxic action. Chiari  described an infant in whom there was no blood pigment in the liver or spleen, and consequently no indications of any antecedent destruction of blood cells. Fischer , in his examination of the older literature, came to the conclusion that many of the cases described as congenital leukemia were probably instances of erythroblastosis.
Fig. 176. Case of erythroblastosis.
 Ztschr. f. Kinderh., 1913, 24, 53.
 Mathem.-naturw. Klasse, 1881, 84, 94 (dritte Abtlg.).
 Jarhb. f. Kinderh., 1897, 45, 177.
 Die angeborene allgemeine Wassersuch, München. med. Wchnschr., 1910.
 Ueber Blutbildung bei fötaler allgemeiner Wassersucht, Ziegler's Beiträge, 1912, 54.
 Ein Beitrag zur Kenntnis der sogenannten fötalen Erythroblastose, Jahrb. f. Kinderh., 1914, 80, 561.
 Die allgemeine angeborene Wassersucht, Deutsch. med. Wchnschr., 1912, No. 9.