The Two Types of Asthma: Typical and Atypical
For years physicians have been trained that all cases of asthma are the same, and good asthma control could be obtained with the same medicines. Yet new evidence suggests there might be two types of asthma, with each requiring a unique treatment plan.
This is a realization that was recently concluded by the asthma experts participating in the Severe Asthma Research Program (SARP). They have defined the two types of asthma as follows:
- Normal or Typical asthma: This type of asthma is easy to recognize and diagnose, and consists of about 90-95 percent of all asthmatics. Their asthma is easy to control with conventional asthma medicaitons.
- Severe or Atypical asthma: This type of asthma is difficult to recognize and diagnose, and consists of only 5-10 percent of asthmatics. Their asthma is less responsive to conventional asthma medicaitons. They are at increased risk of severe asthma attacks, and have a greater risk of dying from asthma. (Check out my post: 35 Signs You Have Typical and Atypical Asthma."
Now for a brief discussion of the two types of asthmatics.
Typical Asthmatic They have a mild or moderate degree of chronic inflammation in their air passages, thus making their air passages hyperactive when exposed to their asthma triggers. When this occurs, their air passages become increasingly narrow, and they get short of breath (what is called an acute asthma attack). They may develop air flow limitation (prolonged expiration) during an attack, but generally have little air trapping, according to SARP. The airflow limitation that occurs generaly takes place in the larger air passages. A gallant typical asthmatic should be able to live a normal life. To them, asthma is just a hobby (some refer to it as hobby asthma). They generally only think about it when it’s acting up, which should be rarely.
What is the treatment?
Since the airflow limitation that takes place is generally in the larger air passages, it is easily reversed with conventional rescue medicine (like Albuterol) and preventative medicine (like Advair and Symbicort). These medicines, when inhaled, easily reach the large air passages, and easily treat and prevent any inflammation and narrowing in that area of the lungs. When using their medicine compliantly, they see a complete reversal of asthma symptoms. When taking their asthma preventative medicines as prescribed, they should never (or rarely) require the use of their rescue medicine. Or, as worded by many asthma guidelines, they should not require the use of asthma rescue medicine more frequently than 2-3 times in a two-week period. As Typical Asthmatics become Gallant Asthmatics, they can gain complete, or almost complete, control of their asthma. There still remains a lot to learn about Typical Asthma, although physicians have had a lot of success controlling and preventing it with so-called conventional asthma medicines.
When to seek help? Help should be sought when peak flow numbers start to decline, or when they notice that they are using their rescue medicine more than 2-3 times in a two week period. Usually a quick trip to the doctor, followed by a short regime of systemic steroids, and their asthma quickly gets back on track.
Severe Asthmatic They have the same chronic inflammation as with typical asthma, although they may also have a certain degree of lung scarring in the deepest air passages, perhaps due to years of uncontrolled asthma. This scarring (also referred to as airway remodeling) makes the tissue lining the air passages thicker, and the air passages chronically narrower. The result of this scarring is that air gets past the scarring and cannot get back out, and this is called air trapping. You can tell you have this when you feel as though you can never finish exhaling all the air out of your lungs even on a good asthma day. Generally, they typically have some air flow limitation (in the larger air passages) during an asthma exacerbation, and continue to have some air trapping (in the deeper air passages) _even on a good day. _ As a result of this air trapping, the use of conventional asthma medicine may not always result in complete reversal of asthma symptoms.
Even as Gallant Asthmatics, or even when their asthma is controlled, they may present with mild or moderate (sometimes severe) shortness of breath. So even when controlled, they may be seen using their rescue medicine several times during the course of the day. Their asthma is generally persistent, intractable, and hardnosed. Some might refer to it as “Double Whammy Asthma.”
What is the treatment?
As with Typical Asthmatics, the general inflammatory component and airway narrowing of the large air passages is treated in the same manner as typical asthma. However, the SARP study showed that even after maximal treatment with typical asthma treatment, these patients may continue to have some airway obstruction. In other words, even after using their rescue medicine, they may still continue to be mildly or moderately short of breath. For this reason, they may require rescue medicine more than what would be considered normal for a Typical Asthmatic.
For airway obstruction nonresponsive to typical asthma medicine, some patients may require more aggressive treatment, such as a trial of higher doses of Advair (The 500/50 dose as compared with the 250/50 dose). It may require a trial of second tier medicines like Brovana/Pulmicort nebulizers, or Spiriva.
The air trapping component is more difficult to control, even with traditional (top-line) asthma medicines. If this condition results in moderate to severe shortness of breath, anti-anxiety medicines and maybe even opiates, like Morphine, may be required to take the edge off. Another option is a new procedure called bronchothermoplasty. Severe Asthma is generally a new diagnosis, and so many physicians may not recognize it, resulting in under treatment, resulting in poor asthma control. Plus one must understand that treatment continues to be in the experimental stages. So ongoing research (which is what SARP is for) is essential.
When to seek help? Help should be sought when peak flow numbers start to decline, or when rescue medicines are needed more frequently than normal. Help should be sought when it becomes difficult to perform normal daily activities, such as sleeping, walking, and working. Conclusion: For years there were many asthmatics (5-10 percent) who never gained asthma control with typical asthma medicines. Perhaps the reason for this was because they did not have typical asthma, but severe asthma. References:
“Severe Asthma May Be a Different Form of Disease,” Science News, Science Daily, http://www.sciencedaily.com/releases/2008/01/080129080656.htm, accessed 9/11/2013
Gaudet, Stephen, “Double Whammy Asthma,” July 15, 2010, Breathinstephen.com, http://breathinstephen.com/double-whammy-asthma/, accessed 9/11/2013
John Bottrell is a registered Respiratory Therapist. He wrote for HealthCentral as a health professional for Asthma and Chronic Obstructive Pulmonary Disease (COPD).