A Study of the Intradermal Test of Rotter for Vitamin C Status

was suggested by Rotter (1937). He observed that when 0.01 c.cm. of a N/400 solution of the dye 2 : 6-dichlorophenol indophenol was injected intradermally, the colour of the dye disappeared gradually. When methyl blue was similarly injected, its colour remained unchanged, which showed that the decolorization of dichlorophenol indophenol was not due to resorption but to reduction. Rotter (1938) also observed that when the dye was injected into an isolated piece of living skin, or into the skin of limbs separated from the general circulation by a ligature, the skin was decolorized as quickly as in normally living skin. This indicated that the fading of colour was not due to the simple migration of the dye. The time taken for the vanishing of the colour was stated to be dependent on the ascorbic acid content of the skin, and the time was related to the vitamin C status of the body. Rotter's observations were confirmed by Portnoy and Wilkinson (1938), Suzuki (1939), Beck and Krieger (1939), Banerjee and Guha (1939, 1940, 1942), Dolle (1941) and Reddy and Sastry (1941). In the hands of Poncher and Stubenrauch (1938), Jetter(1938), Zoccoli and Lombardo (1938), Goldsmith, Gowe and Ogaard (1939), Poulsen and Lieck (1939), Rapaport and Miller (1939) and B^khsh, Kochhar and Malik (1940) the intradermal test received no recognition as a reliable index for the assessment of vitamin C nutrition. Wright and MacLenathen (1939) reported that there was a wide variation in the decolorization time in the intradermal test.