Interesting information could be obtained by analyzing the absorption of fluid injected intradermically in various subjects, and correlating the results with the existence of metabolic offbalances. We used the technique proposed by McClure and Aldrich, in which they measured the time needed for the disappearance of a wheal, resulting from an intracutaneous injection of a saline solution. A relatively extensive study of absorption was made in more than 500 subjects—both normal and abnormal. We present here a few of the conclusions from this study.

The average time necessary for resolution of the wheal obtained by the injection of .2 cc. of 7% NaCl solution, in normal subjects, was 23 minutes; the range was from 15 to 30 minutes. When deviations from these values were observed, they were consistent, in the sense that tests repeated at short intervals in the same general area in the same subject gave values in the same abnormal range. Abnormal values occurred in two directions. Resorption time was shortened in some cases and values as low as 1 to 2 minutes were noted. In the opppsite direction, values as high as 90 minutes were observed. These deviations from normal time could be related to local and general conditions. The presence of local or regional edema shortens the resorption time so much, that in some cases with massive edema, no wheal could even be realized. Shortening of time was found to be true for an edema, regardless of cause—inflammation, impaired local circulation as in phlebitis, impaired general circulation as in cardiacs or in renal failure. Lengthening of resorption time in cases of phlebitis provides valuable information on the evolution of the condition. The return of resorption time to normal values seems to indicate sufficient improvement to permit mobilization of the patient.

In subjects in whom no local factor could be considered to be responsible for changes in the resorption time of the wheal, we could see that abnormal variations had a direct relationship with the general offbalance present. In some subjects with a manifest offbalance of type D, wheal resorption time was shortened. Values as low as 4 to 5 minutes were obtained. Analysis of a number of cases indicated that this shortening of resorption time meant a bad prognosis. A few patients with only values of 2 to 4 minutes died within a few days although other symptoms gave no indication of a fatal outcome within a snort time.

Extended resorption time has been found in subjects with an offbalance of type A. Values as high as 60 to 90 minutes were found in subjects in whom all other analyses indicated this offbalance. It is also interesting to note the existence of slow resorption time for aged subjects. In a group of 80 patients ranging from 70 to 90 years of age, an average resorption time of 90 minutes was found. (Fig. 68)