Can you be denied health insurance coverage if you have asthma?

Yes - Aetna just did it to us because our daughter has asthma. I was so shocked. They stated the reason that her combined conditions of asthma and eczema (yes mild eczema - at least for her) "exceed the allowable limit provided by our underwriting guidelines"

As of January 1st, 2014, this is no longer permissible. No existing condition can be a reason for declining coverage. This is one of the changes that the PPACA (ObamaCare) made.