Testing for food allergy: a statistical comparison of cytotoxic and intracutaneous tests

This study presents a comparison of in vitro cytotoxic food allergy test results with those of in vivo intracutaneous food allergy testing by both objective serial dilution titration and subjective provocation. During the study the cytotoxic test was utilized as a screening device for follow-up Lee intracutaneous testing, the latter providing statistics for both noted in vivo intracutaneous tests. The study is presented in two stages. The first stage documents almost 6000 comparison test results on 300 consecutive food-allergic otolarynogology patients. Thirty-four of the more frequently offending foods were utilized. Of the cytotoxic tests, 86% resulted in positive reactions. Of the positive cytotoxic reactors, 74% were intracutaneously re-checked. Only those negative cytotoxic reactors suspected of false negativity were so challenged, affording comparison statistics for a smaller 21% of the negative reactors. Poor correlation statistics for this select negative reacting group prompted a follow-up 30-patient study on 11 foods that appeared to possess a lesser potential for hypersensitivity production. The second stage emphasizes similar test comparisons on the negative cytotoxic reactors. The study concludes that no correlation exists between in vitro cytotoxic test determinations and those of in vivo intracutaneous testing by objective serial dilution titration or subjective provocation. Because most allergic individuals have multiple food allergies, clinical success utilizing the information obtained from any or all of these procedures may rely significantly on the tests' inherent tendency to identify multiple guilty foods for ultimate treatment.