As for the food allergies, we choose to assume that they last for life. The only way to find out for sure is called a "challenge," in which you eat the risky food with doctors standing by to revive you in case it turns out that, gee, you're still allergic to it after all. Somehow, I don't think we'll be signing up for that.

My sons have adrenaline kits to treat a severe reaction. Neither has ever needed it, and I know they don't carry it around the way they're supposed to when they go to restaurants.

Needless to say, I wish none of this had ever happened. But, based on what's now known, could I have done anything to prevent it? Was it bad that we had cats when our children were born or that we later gave them away? Asthma transformed me and my husband from rather casual housekeepers into mop-wielding fanatics. I'm not sure it helped.

Suppose I had recognized that my own allergies meant that my children would be at risk. Would it have helped if I had then avoided eating nuts, peanuts and shellfish while I was pregnant and breast-feeding? I don't think the answer is clear.

Similarly, I'm not convinced that it would have made a difference if I had been more cautious and methodical about introducing new foods in their first few years, though allergy groups recommend it. The only thing that seemed to do them any good was asthma medicine, and lots of it.

Because children who have even one parent with allergies and asthma have an increased risk of developing the same problems, it would be great if somebody could figure out a way to lower that risk in time to help my sons and the millions of other young people who were also caught in the asthma wave, when they decide to become parents. I am hoping, but I know it may be a problem with many solutions — or none.