Again.....
You're right, cold of winter can trigger asthma, but also a too dry climate indoor air, that is why in summer is reccomended to keep A/C pointed on "cool/wet" funtion rather than "cool/dry" function if you suffer of asthma, that may result in drying air too much.
Said this:
Dust mites are increasd over 50% more of humidity, so high humidity!
Probably I'm not able to let you understand what I mean....
You say: "allergies controls are better in a dryer enviroinment", asthma in most of the cases is related to allergies, I do have allergic asthma showing to April to end of june due to pollen etc,..., I'm not allergic to dust or mites for example....
You're right saying that more the air is moist more the climate is adapt to mites' life that is correct, but keep in mind that in the same way dry climate is good for avoiding mites a dry climate will trigger asthma in other ways than mites, by drying your membranes, causing irritation, this will cause also as said a more chance to get infections and disease.
Said this please read these line copied and pastd by the link I'm a ttaching, maybe it can explain that better than me:
<span style="text-decoration: underline; font-family: georgia,palatino;">As anyone with a chronic lung disease will attest to, humidity can make air harder to inhale. Although, as the
Asthma Educator's Handbook notes,
humidity alone cannot trigger an asthma attack.</span>
<span style="text-decoration: underline; font-family: georgia,palatino;">That in mind, here is the latest wisdom regarding high humidity and asthma:</span>
<ul>
<li><span style="text-decoration: underline; font-family: georgia,palatino;">An
ARIC report notes that areas with a relative humidity lower than 50% had fewer "rates of asthma."</span></li>
<li><span style="text-decoration: underline; font-family: georgia,palatino;">The report also states that "every 10% increase in indoor humidity was associated with a 2.7% increase in the prevalence of asthma."</span></li>
<li><span style="text-decoration: underline; font-family: georgia,palatino;">
The American Academy of Allergy Asthma and Immunology (AAAAI) states high humidity levels also have a tendency to be harboring grounds for fungus and molds that might bother asthmatics.</span></li>
<li><span style="text-decoration: underline; font-family: georgia,palatino;">When humidity is greater than 50%, the amount of dust mites in the air is increased.
</span></li>
</ul>
So you're right saying that but it states also:
<span style="font-family: georgia,palatino;">While we see why high levels of humidity are bed for asthmatics, it's also important to make sure you don't make the air too dry. I say this because new research shows that air that is too dry is not good for asthma either. AAAAI.org reports that if the relative humidity is less than 15%, this may trigger an excessive cough for asthmatics. Low humidity can irritate asthma because it dries out the mucous membranes lining your airway, which are your body's natural defenses against foreign bodies such as viruses and bacteria. Thus, dry mucous membranes make you more susceptible to catching diseases like the common cold virus or influenza. If that's not enough, dry mucous membranes also have the tendency to aggravate allergy symptoms.</span>