Dextran skin tests

Intracutaneous skin tests with 0.05 ml Macrodex were performed in 37 patients, who had experienced anaphylactoid reactions to dextran (Hedin et al. 1976). The incidence of positive wheal and flare responses was 11 % at 0-7 days, and 32% at 1-12 months after the reaction. In normal human subjects, positive skin tests with clinical dextran have been reported in 6%-19% (Bryan and Scudder 1952 Meissner 1961). From these findings it is concluded that skin tests are of limited value for prediction of anaphylactoid dextran reactions. 

Bryan GC, Scudder J (1952) Dextran and pneumococcus polysaccharide cross-reactivity in skin tests and serum precipitin tests. Ann NY Acad Sci 55 477-478 Bygdeman S, Eliasson R (1967) Effect of dextrans on platelet adhesiveness and aggregation. Scand J Clin Lab Invest 20 17-23... 

For skin test diagnostic investigation, dextran (6-10 mg/ml) is used undiluted in prick tests and at a maximum concentration of a 1 in 100 dilution of the prick test concentration for intrader-mal testing. 

In rat-foot oedema tests, chloroquine sulphate in intraperitoneal doses of 10 mg/kg twice daily two days before and immediately prior to a formalin injection was found to be ineffective , whereas other workers have found chloroquine inhibitory in oral doses of 50 mg/kg . In these latter tests mepacrine, proguanil and primaquine, in oral doses of 50 mg/kg, were also effective. Chloroquine sulphate in doses of 10 mg/kg twice daily intraperitoneally for short or long term administration does not affect the development of generalized oedema produced by intraperitoneal dextran or egg-white . When administered chronically it reduces skin inflammation produced locally by chloroform, but is less effective than salicylates . ... 

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