Asthma is a serious problem. However it is very over diagnosed. Plus doctors never seem to look at environmental causes. At least in my experience.
Another stinking hoax.
You know, I've heard that about Lyme too, and that you didn't need to worry outside of New England and MI or WI. And then, they found that 50% of the folks in Papua, New Guinea are seropositive for borrelia. http://tinyurl.com/dvgrs
Asthma can be associated with Lyme, and my son among others has had his asthma go away when the Lyme was treated.