Those can be kind of hit & miss for food allergies. They prick your back with them, but if your allergic reactions happen in, say, your throat, there’s a good chance you won’t show as allergic. I found the pollen/dander prick test to be a lot more accurate than the food test.
According to the one I took, I’m allergic to both pineapple and mushrooms, which I’m not. Also according to the test, I’m not allergic to any tree nuts at all, which eating those make my lips/mouth/throat swell and itch, in addition to making it hurt/difficult to breathe.