How reliable are these scratch tests? I just had one done on my 7 month old son (he has eczema), milk, soy, eggs and cats came up as the biggest reactions. He is EBF and I haven't eaten milk, soy or eggs in months and I have not seen any improvement in his eczema. I guess I am most concerned about the cat reaction as we have 2 and it would break my heart to have to rehome them. Does anyone know how reliable these tests are?