Standardization of allergens by an improved skin-testing technique

From the seemingly most appropriate methods for standardization procedures of allergen extracts, the most serious candidates are in sequence of age: the old atopic skin test, the histamine-release test, using human basophil cells and the radio-allergosorbent test. At the moment it is not yet certain which method gives the most exact results, although, especially in the last ones - as part of the whole test - highly sophisticated methods are used. The skin test is not dependent on modern laboratory methods, is used on a world-wide scale, but as method studied very poorly. This is a matter of regret, because at any rate the skin test gives the clinician a lot of valuable information. The major drawbacks of the skin test are that the inclination of the log-dose response line is rather small and that the results of tests done with the same dose may vary sometimes not inconsiderably. Furthermore, the results are dependent on the sites of the skin where the tests are done and on the amount of fluid injected intracutaneously. There is a diurnal variability, a certain influence of the menstrual cycle and of course influence of medicaments (histamines). Nevertheless, taking all these factors into consideration and using a highly perfected method of skin testing, it appeared possible in 16 experiments, with not more than six volunteers per experiment, to reduce the variability of the bioassay between the limits of +50 and minus 50 per cent.