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Asthma Subgroups: What Is Persistent Eosinophilic Asthma?

Another rare subgroup of asthma is persistent eosinophilic asthma. It’s a subgroup of asthma usually diagnosed in adulthood that is associated with a combination of severe asthma, eosinophilia, chronic sinusitis, and nasal polyps. So, what does all this mean?

What is late onset eosinophilic asthma?

As noted, it’s a combination of:

  1. Severe Asthma. About 15% of asthmatics have difficult to control asthma despite high doses of inhaled corticosteroids and frequent bursts of systemic steroids. About 50-60% of severe asthmatics have eosinophilic asthma, so it’s a significant cause of severe asthma.1
  2. Eosinophilia. It’s a high eosinophil level in either blood or sputum, as determined by a blood or sputum test. Tissue can also be obtained by a procedure called bronchoscopy, where a tube is inserted into your airway after you are sedated. It is commonly present when asthma is uncontrolled or severe.2,4
  3. Chronic sinusitis. This is a sinus infection that always seems to be present. It is associated with a stuffy nose, nasal drainage (which can also be tested for eosinophilia), and anosmia (loss of sense of smell).
  4. Nasal polyps. It’s a soft, painless stalk of skin that hangs down from the roof of your nasal passages blocking the flow of air.5,6
  5. Eosinophilic Otitis media. Sometimes this is also diagnosed. It’s an infection of the inner ear caused by eosinophilia and resulting in thick yellow effusion and gradual loss of hearing. It is generally only diagnosed in people with asthma and is resistant to traditional medicines used to treat otitis media.7,8

Understanding Eosinophils

So, to understand this rare subgroup of asthma, we must have a basic understanding of what eosinophils are, along with their role in asthma.


Eosinophils are responsible for about 50% of all cases of asthma, particularly childhood-onset and allergic asthma (extrinsic). They are white blood cells (leukocytes) made in the bone marrow that are summoned to your airway during asthma attacks. When they come into contact with airway cells they release their contents, which include chemicals that cause both upper and lower airway inflammation, meaning the sinuses, nasal passages, and lower airways.7,9,11

Persistent Eosinophilia

It’s defined when eosinophils in sputum represent greater than 2% of inflammatory cells for five consecutive years.13 It is sometimes diagnosed in childhood, although it’s most often diagnosed in adulthood, which is why it is often referred to as Late or Adult-Onset Persistent Eosinophilic Asthma.

Lower airway inflammation

Asthma is considered a disease associated with some degree of chronic (it’s always there) underlying airway inflammation. This makes your airways twitchy to asthma triggers, exposure to which cause asthma symptoms. Eosinophils play a key role in this inflammation and are probably responsible for it becoming chronic.


Steroids suppress the chemicals responsible for eosinophil recruitment and also cause eosinophils to die (called apoptosis). This reduces eosinophil counts, reduces airway inflammation, and makes airways less twitchy. This results in improved asthma control.7,13

Childhood-onset allergic asthma and adult-onset eosinophilic asthma both present with eosinophilia. However, most cases of childhood-onset allergic asthma respond well to low doses of inhaled corticosteroids, while most people with persistent eosinophilic asthma respond poorly to low doses of inhaled corticosteroids. This means that allergic asthma is easier to control than eosinophilic asthma. What causes this difference between early and late onset asthma is unknown.13

This means that most cases of late-onset eosinophilic asthma are associated with persistent eosinophilia despite the highest doses of inhaled corticosteroids and frequent boosts of systemic steroids. This means they have severe asthma.7

Digging deeper into eosinophilic asthma

Sputum Eosinophilia

A sputum sample can be easily obtained and taken to a laboratory where eosinophil cells can be counted. For most asthmatics, sputum eosinophils are elevated when asthma gets worse and decrease when asthma improves, such as when corticosteroids are used. Persistent sputum eosinophilia despite the highest doses of steroids is the best indicator of persistent eosinophilic asthma.4,11,12

Upper airway inflammation

Eosinophils are known to infiltrate tissues of the upper as well as the lower airways, this may lead to sinus infections, nasal polyps, and eosinophilic otitis media, all of which are very difficult to treat, and may require a referral to an ear, nose, and throat (ENT) doctor. Antibiotics may help with sinusitis. Systemic corticosteroids (prednisone) may help with otitis media. Even following surgery to remove nasal polyps, they often grow back, and sometimes quickly.7,10


Eosinophils may be abnormally elevated due to the presence of certain asthma genes. These genes, or gene mutations, may encode proteins that tell immune cells to produce in abundance chemicals responsible for eosinophil recruitment. Researchers have theories to explain the exact mechanism involved, which I may discuss in a future post.

Airway remodeling

Early diagnosis of eosinophilic asthma is important, as prolonged and untreated airway inflammation may lead to lung scarring or an abnormal thickening of airway walls. Chemicals released by eosinophils may also play a role in airway scarring. This causes permanent airway narrowing, resulting in asthma that is only partially reversible. This may sometimes be confused with Chronic Obstructive Lung Disease (COPD).1,7,11

Dyspnea tolerance

Similar to COPD, some shortness of breath may be present even on a good asthma day. This may cause a blunted sense of shortness of breath. When asked how they feel, even though you may observe the signs of asthma, they may say, “I feel fine.” This is something their doctors have to watch out for. Rather than using symptoms monitoring to decide what actions to take, they may be better off using peak flow monitoring.7

Other overlapping subgroups

There are other asthma subgroups that may overlap with eosinophilic asthma, and these include allergic asthma (sometimes) and Aspirin Exacerbated Respiratory Disease (frequently). It may also be associated with allergic bronchopulmonary aspergillosis and Churg–Strauss syndrome.11


Eosinophilic asthma is a rare subgroup of asthma, and it may often go undiagnosed. However, if recognized and treated aggressively, good asthma control can be obtained.

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.

  1. Katial, Rohit K., editor, “Clinical Review Articles: Immunology and Allergy Clinics of North America; Severe Asthma,” August, 2016, Elsevier, Philadelphia
  2. Mayo Clinic, eosinophilia,, accesed 10/16/16
  3. World, slide, Defining Phenotypes: Expanding Our Understanding Of Asthma Challenges In Treating Heterogeneous Disease,, accesssed 10-17-16
  4. Nair, Parameswaran, “What is an ‘eosinophilic phenotype’ of asthma?” Journal of Allergy and Clinical Immunology, July, 2013,, accessed 10/24/16
  5. Mayo Clinic, nasal polyps,, accessed 10/28/16
  6. Mygind, et al., “Nasal Polyposis, eosinophil dominated inflammation, and allergy,” Thorax, 2000,, accessed 10/28/16
  7. Jantina, et al., “Management of the patinet with eosinophilic asthma: a new era begins,” European Respiratory Journal, 2015,, accessed 10/17/16
  8. Lino, Y., “Eosinophilic otitis media: a new middle-ear disease entity,” Current Allergy Asthma Reports, Nov., 2008,, accessed 10/17/16
  9. NHLBI Asthma Guidelines, page 18,, accessed 10-20-16
  10. Gaga, et al., “Eosinophils are a feature of upper and lower airway pathology in non atopic asthma, irrespective of the presence oif rhinitis,” Clinical and Experimental Allergy, May, 2000,, accessed 10/1716
  11. Walford, et al., “Diagnosis and management of eosinophilic asthma: a U.S. perspective, Journal of Asthma and Allergy, 2014,, accessed 10/17/16
  12. Barnes, Peter J, Jeffery Drazen, Stephen Renard, Neil C. Thomson, editors, “Asthma and COPD: Basic Mechanisms and Clinical Management,” 2nd edition, 2009, page 546
  13. Wenzel, Sally, “Asthma Phenotypes: The evolution from clinical to molecular approaches,” Focus On AsthmaI, 2012,, accessed 10/30/16


  • Micheles248
    10 months ago

    Wow, sounds exactly like my breathing issues.

  • Leon Lebowitz, RRT moderator
    10 months ago

    Hi again, Micheles248 – glad to see this article resonated so clearly with you. Wishing you well, Leon (site moderator)

  • Countrymama74
    1 year ago

    2 years ago I was diagnosed with EOE(Eosonophillic Esophagitis). I am wondering now if considering my chronic asthma, I might actually have the Eosonophillic Asthma. I am going to ask my pulmonologist on my next visit.

  • John Bottrell, RRT moderator author
    1 year ago

    All your doctor needs to do is order a complete blood count with differential. I imagine, considering your EOE diagnosis, you’ve probably had this done already. It would be really neat to hear what your doctor has to say about this. Do keep us posted. John. Site Moderator.

  • Countrymama74
    1 year ago

    I have had Asthma since birth, and have died 3 times due to severe attacks. My pulmonologist in Ohio told me I have the asthma that kills. In Ohio I was labeled Chronic Severe, because I was on daily Prednisone for 5+ years. Since living in AZ I only take Prednisone during severe flare ups. But still do daily treatments and on a handful of medications, better than the dozen or so I was on in Ohio.

  • Leon Lebowitz, RRT moderator
    1 year ago

    Hi Countrymama74 and thanks for your post(s). We appreciate you sharing just how significant an improvement your relocation to Arizona provided for your condition. Please do check back and let us know what the pulmonologist was able to do for you. All the best, Leon (site moderator)

  • sulliho
    1 year ago

    Great article. Three years ago, I had a severe bought of Eosinophilic Pneumonia. I was hospitalized and was treated with steroids for a long time. Even though I have asthma (adult onset), no one ever mentioned or talked to me about the possibility of Persistent Eosinophilic Asthma. I’m reading this and see lots of overlap. The only thing that doesn’t fit is that my asthma, most of the time, is not “serious” in that I rarely use my inhaler except before exercise. I am very interested in learning more.

  • Leon Lebowitz, RRT moderator
    1 year ago

    Hi sulliho and thanks for taking the time to let us know the value you found in John’s article. We appreciate your input. You’ve certainly come to the right place as we are all about all things asthma. In view of your concern with ‘adult onset’ asthma, I thought you might also find it helpful to look over this article on that very topic: Please know you are always welcome here! Leon (site moderator)

  • John Bottrell, RRT moderator author
    1 year ago

    Hi. sulliho Thanks for the kind words. Have you considered discussing this with your doctor? I would imagine this could develop into an interesting discussion. John. Site Moderator.

  • eugenia117
    2 years ago

    Hello, I just read your article from Nov 2016 on EGPA. It was very good and a nice summary. I was diagnosed a few years ago. I was on Nucala, now Cinqair.

    Do you know who is doing the gene research?

    Thank you,


  • John Bottrell, RRT moderator author
    2 years ago

    HI. Deborah. Thanks for the update. Great to hear you are doing better.

  • GeorgePayne
    2 years ago

    I was misdiagnosed for about 5 years. Was being treated for allergies that I did not have. I am a severe asthmatic, diagnosed at 53. I’m now 60. I used multiple inhaled steroids and prednisone. I never seemed to improve. I finally had a surgeon friend refer me to another medical team. Thank goodness.

    Two things were life changing: sinus surgery and a test for eosinophilic levels. I had a high count and now get an injection each month of a very expensive drug called Nucala. It lowers eosinophils.

  • John Bottrell, RRT moderator author
    2 years ago

    Sure does make a difference once you get a proper diagnosis and treatment. It’s also great to have a friend like that. Glad to hear things are going better for you. Please do keep us posted.

  • willow88
    2 years ago

    Thanks for this informative article. Indeed for 18 months I have been struggling with a diagnosis of asthma/copd which turned out to be wrong. I have been on a steady diet of Fostair / Ventolin, punctuated every few weeks by a mega dose of prednisone in order to be able to function at all and stay out of hospital. Despite being admitted several times last year and visiting my GP almost weekly ever since, nobody had ever mentioned eosinophils or noticed that they were elevated in all my blood tests.

    I noticed that myself after reading about eosinophilic asthma online and then ordering print outs of my blood tests over the past several months. Voila! Bringing this to the attention of a new consultant today, he immediately confirmed that I have eosinophilic asthma and has prescribed a different course of treatment.

    This is a cautionary tale; we need to do our own homework! In my case the initial consultants jumped on a copd diagnosis, then adjusted it to asthma/copd but never, apparently, looked at my eosinophil counts. I wonder how much damage has been done during this 18 months of alternating between exacerbation and prednisone + side effects?? ………………………

  • John Bottrell, RRT moderator author
    2 years ago

    Hi. Willow88. Thank you for sharing your story. Keep in mind that it has only been in the past 20-30 years that researchers have recognized asthma subgroups like eosinophilic asthma. So, this might explain why so many people who have it go undiagnosed, or misdiagnosed as in your case. Your story is a true testament of how much more work researchers have to do not just in learning about asthma subgroups like yours, but teaching asthma physicians how to better diagnose and treat it. You are right! We all do need to do our homework. John. Site Moderator.

  • willow88
    2 years ago

    Hello John, An update since our last exchange… on Dec 20, 2017 the consultant who initially diagnosed me with eosinophilic asthma rather than copd sent me to see his partner at Nevill Hall, Abergavenny. This was Dr Pynn, an asthma specialist consultant. He confirmed 200% the EA diagnosis, not COPD. I had had something of a setback with a cold and he added Uniphyllin to my daily meds. Since then I have been extremely stable. Basically, since the re-diagnosis and change of meds to Fostair + montelukast + uniphyllin, I have been able to return pretty much to my old self… walking fast in any weather, ballet classes, teaching dance & pilates. Nor have I had to use Prednisone at all since September and the Ventolin literally only a couple of puffs when I had the cold. It has been a transformation. I have submitted a complaint to Wye Valley Trust Hereford about my erroneous treatment at Hereford County. EA is not new, nor are montelukast / uniphyllin. There really is no excuse for the consultants there to have been so wrong. Best, Deborah

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