There are pros and cons to all flooring. Carpeting is known to be an ideal environment for dust mites and pet dander. However, it traps dust so it isn’t circulating around the room and stays put until vacuumed. Hard surface flooring is easy to clean and maintain, but can’t hold the allergens so they become airborne.
Carpet does cost about 30 to 50% less than hard surface flooring. A low pile carpet is a better option for cleaning than a deep pile because it is easier to vacuum more thoroughly. A tight-looped natural fiber like wool and sisal are both known to not promote the growth of bacteria or dust mites; however, these natural fibers can be pricier. Going with a polypropylene is another option, which is impervious to moisture and inherently mold proof. No matter which fiber choice, adding a hypoallergenic, low VOC padding like Shaw’s Triple Touch can be beneficial, too.
Plush carpet, tight and looped carpet, natural fiber carpet, synthetic carpet, hard surface flooring… ANY flooring can be a problem if you don’t keep it clean. Vacuum frequently with a HEPA (High Efficiency Particulate Air) vacuum to retain allergy-causing particles from becoming airborne. The use of air purifiers with HEPA filters is also a plus. The most important thing is cleaning and elimination of other triggers, like tobacco smoke, will help any asthmatic do better.
You don’t need to limit your flooring choices just because of allergies and asthma. There aren’t any health benefits to removing carpeting. It doesn’t matter what type of flooring you have - all you need to do is keep surfaces clean on a regular basis.