blood tests aren't very reliable like that. i have been with my partner to the immunologist many times over the years and observed skin prick tests and seen blood test results and watched her get epipen'd after a bad prick test.

she will go into anaphylaxis if you wear a jacket you brought to somebody's house who has a cat.

her blood work says the IgE count is fairly low.

they can indicate more testing should be done, but they aren't perfect. neither are skin prick tests. i can dig up some of her reddit comments about it if you're interested.