The problem isn't that allergens cause the allergy immediately. If a baby eats something that is an allergen and is fine afterwards it doesn't mean that that is fine... The allergy can develop years later and the allergens might have helped that. Anyway, new research has been found that even children who's parents do have asthma, eczema and hayfever can have small amounts of dairy after 6 months.
On the other hand, I never did just to be on the safe side and he was missing out on a lot of stuff...
The German Association for Asthma and Allergies has just found out that due to the precautions the people take (mainly the feeding of hypoallergenic formula that is not available here, not talking about Nutramigen) has decreased the numbers allergies and asthma for the first time ever. Germany's children now have less allergies and asthma than just a few years ago because of the knowledge given to the parents. As far as I know in all the other countries the numbers are still rising, just in Germany they are dropping. Because DH has asthma, eczema and hayfever we have been informed what to do very well and got loads of leaflets and addresses and info at his birth. It is also all marked in his wee health book even if he never had any symptoms.