Correlation of Modified Radioallergosorbent Test Scores and Skin Test Results

In addition to a significantly increased sensitivity as compared with the initial Phadebas radioallergosorbent test, a major advantage of the Fadal‐Nalebuff modified RAST is its correlation with skin testing using skin end point titration. This correlation allows physicians to use both these modalities in the diagnosis and treatment of allergic disorders. However, it has been anecdotally believed that the correlation of radioallergosorbent test classes and skin test end points varied somewhat with different antigens. Fifty‐three patients were tested by radioallergosorbent test for 12 inhalant antigens common to the North Texas region. These patients subsequently underwent confirmation of their radioallergosorbent test results by application of intradermal tests at a concentration of one fivefold step weaker than the corresponding radioallergosorbent test level (a “RAST minus one” dilution). The relationship between radioallergosorbent test and skin test results will be critically analyzed.