First of all, I am an asthma specialist with an MD. Anything I right is my opinion, doesn't represent the opinion of all specialists in asthma or even the other doctors in my practice.
Everyone reading this has to have had some personal contact or knowledge of someone with asthma. There are almost certainly kids in your kid's class with inhalers. You may have family or personal experience with asthma.
The asthmatic response is two-fold. The bronchial tissues become inflamed. The thought is that if this is ongoing, eventually, you will get contraction of the smooth muscle around the airways which causes bronchospasm.
Asthma can show up as a cough, without any other symptoms. Some people don't wheeze. I have had many patients who went to the ER and were unfortunate enough not to wheeze. They were told they had reflux or anxiety. Some were given extensive cardiac workups. Even a spirometry test (done my measuring the rate and quantity of air that someone can exhale) can be normal in milder asthma. Still, asthma awareness has increased and people with milder asthma are diagnosed and treated more effectively than ever before. Some of this has to do with the increased incidence of asthma. Some of this, admittedly, has to do with pharmaceutical marketing to doctors and patients.
Since inhalers have been around, more and more people are being treated with preventative inhalers and asthma mortality has gone down, despite the large increase in prevalence and incidence. There are some that worry about the long term effects of the salmeterol (long acting bronchodilator in Advair). Newer studies reveal that if you are taking a low dose inhaled steroid (which is in Advair) the risk of becoming used to the bronchodilators and developing worsening asthma is pretty unlikely. Many people are treated with inhalers and lead normal lives. We've all heard about Olympic athletes with asthma that break world records.
Still, wouldn't it be nice if more research went into the root causes of the asthma epidemic rather than just to new pharmaceuticals?
It is widely accepted that asthma incidence and prevalence are increasing, worldwide. It is not an artifact due to increasing diagnosis or more treatment. People are getting better treatment, but more people than ever need it. Interestingly, asthma is most prevalent in industrialized countries.
There are many theories as to why this is. Obviously, genetics cannot explain an increase like this.
The "Hygiene Hypothesis" has been around for decades. The idea is that because there is better sanitation and children suffer from fewer infections, the immune system has nothing better to do than to create inflammation and cause allergies and asthma. There are some studies that reveal that children from farms and children from larger families, who would be sick more often, have a lower incidence of asthma. I find this theory plausible, but a little hard to swallow, given the incredible adaptive nature of our immune systems and the many other factors that, in my opinion are probably playing a bigger role.
There are theories regarding tylenol use in pregnancy, antibiotic use and vaccines. None of them are agreed on.
I find the idea that particulate matter in the air causes airway inflammation and respiratory problems pretty obvious and sensible. Unfortunately, the medical community is only beginning to come around to this. In my opinion, they haven't seen the forest for the trees. There are some reasons for this. First of all, several cities decreased certain particulate air pollution, such as sulfur dioxide and carbon monoxide during the eighties and nineties. Still, asthma increased. Secondly, there are many factors to evaluate that make everything more complicated.
Personally, I think that the problem is that automotive exhaust and diesel fumes were not adequately taken into account. Why is the inflammation of parasitic infection and allergy/asthma pretty much identical. Both reactions involve the exact same molecules, such as IgE and eosinophils. Mediators such as IL-4 and IL-5 play a role in both reactions.
There are several studies connecting diesel fumes and asthma symptoms Journal of Allergy and Clinical Immunology
I have always that that the irritation of the airways from particulate fumes mimics that chronic irritation from a parasite on the mucous membranes. Of course, this is just my speculation.
There has also been epidemiologic evidence that regular old automotive exhaust can cause asthma. People who live near highways are more likely to have asthma.
The above may seem like a "d'uh" to many lay people, but again, it has not been written in stone.
My attitude is that it doesn't have to be, in order to enact even stricter emissions standards on cars and increases in funding for public transportation. Can we really look at the asthma epidemic and refuse to act?
I'm adding a link regarding climate change and asthma, since this is also a big factor. Link