I don't recall now since it's been more than 7 years and it was one of his more minor issues, but the specialist had explained that there is something in the way Zyrtec (Cetirizine) works, which makes it the best choice for my oldest DS for his combined issues.

Fortunately, at least asthma isn't an issue for any of my kids. Their cousins aren't as fortunate in that regard and it can be pretty scary to witness.

We normally don't stop the antihistamine for hay fever until November so that should give me a chance to talk to their pediatrician at least.