Regional Variability of Skin Hypersensitiveness to in Guinea Pigs and Rabbits

Abstract

It is well recognized that variations in the intensity and constancy of hypersensitive cutaneous reactions occur in the human subject with respect to different regions of the body. As far as similar variations in animals are concerned, however, few observations appear in the literature. The object of the present study was to ascertain whether different skin areas of guinea pigs and rabbits sensitized to would react in a similar or in a different manner to subsequent intradermal injections of this drug. The experiments included 9 adult male albino rabbits and 12 adult guinea pigs; in the latter animals the skin of the flanks and abdomen was non-pigmented. The solution was prepared and the animals were shaved according to the technique described in the preceding report. The rabbits were sensitized and tested for hypersensitiveness with 0.2 cc. and the guinea pigs with 0.1 cc. The injections which were given with a sharp tuberculin needle and a. tuberculin syringe calibrated to 0.01 cc, were made as equally deep in the epidermis of the flank and abdomen as possible; the wheals formed were of approximately the same area and depth. The test for hypersensitiveness was made 5 weeks after the first or sensitizing injection. The reaction was read 24 hours after injection, the width and breadth of the involved skin area being measured. The results shown in the accompanying table indicate that there was a distinct variation in the reactions on the flank and abdomen in every animal, those on the flank being larger than those on the abdomen. Furthermore, in 8 of the 12 guinea pigs and in 4 of the 9 rabbits, there was practically no reaction in the abdominal area in contrast to the definite flank reaction in each case.