I had a bunch of allergy blood tests after having an allergic reaction to kiwi fruit. My results came back "severely allergic" to almond and sesame, both of which I have eaten all my life with zero issues. No antibodies to any of the pollen I am actually allergic to or to kiwi. I didn't show any allergies to anything when they gave me a skin prick test either, despite having had hay fever my entire life, which was ultimately the cause of the kiwi allergy via oral allergy syndrome. The doctor basically shrugged and told me "allergy testing is more of an art than a science."