Asthma Subgroups: Severe Asthma.

Asthma Subgroups: Severe Asthma

One of the most recently defined asthma subgroups is severe asthma. It was first defined about 20 years ago. This was when physicians recognized 5-10% of asthmatics did not respond to corticosteroids. They continued to have difficulty to control asthma despite the best treatment. Here’s what researchers currently know.2

What is difficult to treat asthma?

It’s asthma that is difficult to control. It could be due to…

  1. Misdiagnosis. The person is being treated for asthma but does not have asthma. Various diseases mimic asthma (like COPD or obesity) but do not respond to asthma medications. So, the road to improved symptoms in these cases may begin with a proper diagnosis.2-6
  2. Poor patient compliance.The person has asthma but isn’t adhering to a treatment program. They may be forgetting to take their medicine. They may not be taking it right. The road to better asthma control may be education.2-6
  3. Severe Asthma. I will describe this in a moment. First, a misdiagnosis and poor patient compliance must be ruled out. Once that’s done, a diagnosis of severe asthma can be made.2-6

What is severe asthma?

How to define severe asthma was open to debate until 2014. This was when a joint conference of the American Thoracic Society and the European Respiratory Society defined it as:

“Severe asthma refers to asthma that:

  1. requires treatment with high-dose inhaled corticosteroids (ICS) plus a second controller during the full previous year and/or systemic corticosteroids (CS) during 50% or more of the previous year to prevent symptoms from becoming “uncontrolled,” or
  2. remains “uncontrolled“ despite this therapy.”4

What is refractory or steroid refractory asthma?

According to Merriam-Webster, refractory means “resistant to treatment.” So, refractory asthma refers to asthma that is resistant to treatment. Steroid refractory asthma refers to asthma that is resistant to corticosteroids. Some severe asthmatics have this.

What is the treatment for refractory asthma?

Traditional asthma medicines like inhaled corticosteroids are usually tried. The highest doses are usually needed. Non-traditional, or second-line, asthma treatment may is often used. This may include medications like Singulair or Xolair. It may include using COPD medicine like Spiriva. It may include trying old asthma medicine like theophylline. It may include using unique treatments like macrolides, antifungal agents. It may include a surgery called bronchial thermoplasty.2, 4-7

What causes steroid refractory asthma?

Airway remodeling is a common cause. This is where airway walls are thicker than normal and not responsive to treatment. Asthmatics who present with neutrophilic airway inflammation may cause it. This type of inflammation may come with a diagnosis of Asthma/ COPD Overlap Syndrome. It may includePremenopausal or Occupational Asthma.

What other subgroups may cause severe asthma?

Late-Onset asthma tends to be more severe. (3). Late-onset subgroups include Eosinophilic and Aspirin Associated Asthma. It may also include Allergic Bronchopulmonary aspergillosis or Churg Strauss Syndrome.

What else might cause severe asthma?

About 19-34% of severe asthma cases involve asthma that exists with another co-morbidity.1 Examples include allergies, rhinitis, COPD, GERD, stress, or anxiety. When this is the case, controlling one means controlling the other. Sometimes, even Allergic Asthma can become severe. This is because it consists of both allergies and asthma. In such instances, severe asthma may be diagnosed in childhood.1, 7-8

How is a diagnosis of severe asthma helpful?

After diagnosing severe asthma, a quest can begin to determine why it’s severe. Is it because of your subgroup? Is it because you have more than one subgroup? The answers to these subgroups can lead you and your doctor a treatment regiment that works for you. This is all an attempt to help all asthmatics reach ideal asthma control.

This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.
View References
  1. Wenzel, Sally, “Asthma Phenotypes: The evolution from clinical to molecular approaches,” Nature Medicine, 2012, May, 18 (5), pages 716-725,, accessed 5/21/17
  2. Currie, Graeme P., J. Graham Douglas, Liam G. Heaney, “Difficult to treat asthma in adults,” British Medical Journal, 2009,, accessed 7/18/17
  3. Wenzel, Sally, “Severe Asthma: Can phenotyping help with understanding and treatment,” UPMC Physician Resources,, accessed 9/20/17
  4. Thomson, et al., “ATS CLINICAL PRACTICE GUIDELINE: SUMMARY FOR CLINICIANS,” American Thoracic Society, 2014,, accessed 10/10/17
  5. “International ERS/ATS Guidelines on Definition, Evaluation and Treatment of Severe Asthma,”, 2013,, accessed 5/22/17
  6. Wenzel, Sally E., K. Fan Chung, editors, “Difficult to Treat Severe Asthma,” European Respiratory Monograph, March, 2011, Number 51, page 21-23
  7. Wenzel, Sally E., “Severe Asthma In Adults,” American Journal of Respiratory and Critical Care Medicine, 2004, September,, accessed 7/14/17
  8. Severe Asthma Research Program,, accessed 11/5/17


View Comments (2)
  • susansetley
    1 year ago

    Severe asthma has put me in the hospital 13 times in the last 17 months, and you know what the worst of it is? Since your personal phycician no longer sees patients in the hospital, there’s been a never-ending train of hospitalists, all certain that I really have something else—at 71 COPD, or vocal cord dysfunction (I’m a classically trained singer who can sing through wheezing; it can’t be that); lyrngeospasms (you’d think I would have noticed at least once that I couldn’t breathe AT ALL); some unspecified heart problem (bring in the echocardiogram machine—great heart function); etc., etc., etc. NO. I have severe, persistent asthma on sometimes up to nine medications, and YES I use them as I’m supposed to, and I wish someone from the hospital would stop calling once a week to ask if I’m adhering to my medical regimen as if I were some naughty eight year old.

    IRS certain the asthma will put me back in the hospital, because I AM responsible. Although I hate, hate, hate the Hospital I will call 911 just as I did last time, and the time before that, and the time before that.

    And I know that some hospitalist will dream up some new and (to me) bizarre possible alternate explanation for the obvious: I’m one of those few unlucky people who suddenly developed severe asthma late in life after never having had it before. I think these hospitalist know that people with my asthma pattern exist, but they can’t resist coming up with some improbable alternate explanation.

    Leave me in peace and just treat the asthma. Believe me, I wish it were more responsive too, but it is what it is. I’m lucky. At my age, the first thing they checked for was lung cancer. It could be worse.

  • John Bottrell, RRT moderator author
    1 year ago

    Hi. susansetley. Thanks for sharing. As a respiratory therapist, I love hospitalists. I love that they are always available. However, you have just highlighted one of the problems with hospitalists. It’s not that hospitalists are bad, it’s just that it’s hard when you have a different doctor when you’re admitted. You have to explain yourself over and over again to each doctor. And you go through all this needless testing each time. I know that some patients come to the ER with notes from their family doctors. These notes say what you have and what treatment works best for you. I actually had a note like this when I was a kid with severe asthma (of course back then they didn’t call it severe asthma). So, anyway, just wanted to share that I understand where you’re coming from. Hope all goes well. Keep us posted.

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