A pandemic? First let's consider that

1. There are more allergy sufferers than ever because there are more people than ever. 7,000,000,000, give or take. An unchanging percentage of a bigger population = more sufferers.

2. There is more communication than ever. Because of the Internet and the media, we hear about cases we never would have heard about before. For example, I in Kansas City hear about Will's grandson in England. That wouldn't have happened in 1950.

3. Because of increasing education and awareness, people who would never have thought about allergies (describing an attack as bad luck, evil spirits, God's will, etc) now are aware of the true nature of the problem.

4. Because of awareness, people who would not have survived childhood are growing up and having children who may inherit the problem. They may even marry others who also have problems.

It would be difficult to quantify all the above, but it would be foolish to ignore it and declare a pandemic.