I cant say for certain but as far as Im aware more emphasis is placed on the initial reaction as to how quickly it took to establish and how severe it was once established. We've only done the SPT so I can't really comment on the RAST side of things, your allergist should definately go over it with you. I know with the SPT that the reaction on the day doesnt indicate how a reaction may go to accidential exposure just that they are positive to them, unless they are exposed they cant say for certain that it will affect their airways etc, just that it is present. Also allergies will change over time especially when they present so young, however there are some that are more likely to be with you for life (such as tree nuts). It is also possible to tolerate some allergens in different forms, for instance DS can tolerate small amounts of well cooked egg in things like cake and biscuits but he cant tolerate an omelette or raw batter. Other reactions are more severe... he cant even look at a dog without going blotchy, but thus far none of those have affected his airways. We are yet to have exposure to his nut allergies and given that we have anaphalyasis in the family for those we are to avoid them. Im not sure that any of that helps lol sorry!

We too carry around zyrtec and his asthma inhalers.