Transcription:
Hypersensitivity Pneumonitis: What Are the Most Common Causes and Treatments?

Bill Klaproth (Host):  This is Bill Klaproth in for Melanie Cole. Breathing in certain substances often causes hypersensitivity pneumonitis. What are the two types of hypersensitivity pneumonitis and what are the causes and treatments? Here with us today is Dr. Diana Gomez. She is a UVA specialist in pulmonology, a board certified physician in internal medicine whose specialties include hypersensitivity pneumonitis and interstitial lung disease. Dr. Gomez, thank you so much for being on with us today. Let’s start right here. What is hypersensitivity pneumonitis or HP?

Dr. Diana Gomez (Guest):  Good afternoon. Hypersensitivity pneumonitis is a lung condition that is caused by inhalation of some type of allergen that is in the environment, usually mold or a bird antigen and when I say that, I mean an exposure to chicken or feathers could cause it. What you see in the lungs is some inflammation, sometimes its scar tissue. The reason why this happens is because it is an immune response to these allergens that are in the environment. It can happen from exposures that you have at home or actually in your work environment.

Bill:  When you say “inhaled substances” such as mold or chicken feathers, things like that, I’m thinking of a guy on a construction site inhaling sawdust or concrete dust or some type of insulation dust. Can somebody get hypersensitivity pneumonitis from that, too?

Dr. Gomez:  What usually happens is the dust that you get exposed to in a construction environment causes a different type of condition. It’s not hypersensitivity pneumonitis. It’s called “pneumoconiosis,” which is completely different. Hypersensitivity pneumonitis happens when people are exposed to organic allergens.

Bill:  Okay, now I understand. Very good. I just wanted to clarify that for people listening right now. Are there different levels of HP?

Dr. Gomez:  Yes. The presentation is different. The big groups are acute presentation and chronic presentation and the symptoms vary accordingly. When a patient has acute hypersensitivity pneumonitis, the most common symptoms happen four to six hours after the exposure. Usually, people have fever, flu-like symptoms. They feel tired, headaches, chest tightness, cough, shortness of breath. Those last for a few hours until the exposure is resolved. It is acute and improves in a few hours. The other type is called “chronic HP” or “chronic hypersensitivity pneumonitis” and that happens to patients that are being exposed without them knowing that they have the exposure. They don’t have this acute presentation. They just start feeling short of breath and start coughing over time. When we see them in clinic, they already have scar tissue in the lung. They never had an acute presentation or they maybe just thought it was a viral infection and they just disregarded it. When they come to clinic, it is a little advanced, if you want to say it that way. There is already scar tissue in the lungs.

Bill:  Someone with acute the symptoms come on hard and fast. Do they go away, then?

Dr. Gomez:  Yes, they go away. They usually go away after they stop exposure to the allergen.

Bill:  Someone with chronic, this is where they are constantly coughing, maybe having tightness of chest, breathing issues where they are constantly having it?

Dr. Gomez:  Right. They present with a more chronic picture. Like, it happens over a month, most of the time.  

Bill:  What are the classic symptoms then? Is it mainly the coughing and shortness of breath?

Dr. Gomez:  For the chronic one, yes. Cough, shortness of breath. Some people have some unintentional weight loss.

Bill:  How can someone be diagnosed with HP?  

Dr. Gomez:  Unfortunately, we don’t have a system that is evidence based yet because it is a condition that we need to have much information before we come to the diagnosis. Basically, we need to get a very good history from the patient. We always ask them about exposures and, as I said, mold exposures. We usually see this in people who have humidifiers, dehumidifiers at home, any water damage in their basement, or they live on a farm and they have moldy hay. In the history, the patients have to tell us about the exposure. The next step will be some blood work. If the patient is unaware of exposure, the blood work may tell us if they are being exposed to something that could cause this condition. The next step is a CT scan or some type of chest imaging and there are some changes. One of them is scar tissue, some inflammation in the lungs. There are certain patterns that we see that make the diagnosis higher on our list. After the CT scan and all of the blood work, then we may consider something called “bronchoscopy:. That is when we go inside the lungs with a camera and get some fluid washings and then some type of cells that we get from those washings will make the diagnosis, again, more possible. Sometimes just with exposure with the CT scan and the bronchoscopy, we can make the diagnosis but if it still unclear to us why the patient has this issue we may need to get biopsies. The way that we do them is doing the same procedure as the bronchoscopy. When we do the washings, we will do some cell bronchial biopsies. They actually have a high yield to make the diagnosis. But, if those are unrevealing the next step will be a surgical lung biopsy. Of course, it is patient based. We want to make sure that the patient’s lung function is good enough for them to undergo that type of invasive procedure. We need different information before we come up with the diagnosis. There is not a straightforward diagnosis.

Bill:  If someone is diagnosed with HP then, it is really incumbent upon them to find out what in their environment is causing this. Correct?

Dr. Gomez: That is correct. Actually, sometimes when we send the blood test in and it comes back positive for mold exposure or chicken exposure, sometimes they have to have the house professionally inspected because sometimes they are unaware of the exposure.

Bill:  Right. Then, you know. If left untreated can this disease lead to something more serious?

Dr. Gomez:  The acute presentation the patients usually do okay, meaning they stop the exposure and then they improve. But people who present with chronic HP, they can progress to respiratory failure, meaning they will need oxygen. They may retain carbon dioxide. It’s a little more serious once the lungs are scarred down and, unfortunately, we don’t really have medications to get rid of the scar. If it’s inflammation, we can use medication to improve the inflammation but once there is scarring in the lungs, then, unfortunately, there is not much that we can do at that point.

Bill:  So, it’s crucial to find out early what in the environment is causing the HP and get rid of it so you don’t wind up in a situation where you do have scarring of the lung. What treatment options are available to somebody with HP?

Dr. Gomez:  As you said, actually, the main goal is to identify the allergens and avoid further exposure. If there are birds, remove them. If the patient has been exposed at work, then they need to change jobs. Actually, some people actually had to change houses just because they were exposed and they couldn’t remediate the mold. It’s that serious. If they fail to resolve the allergen exposure, that will, of course, increase the chance of progression and development of this irreversible lung damage.  

Bill:  They’ve got to find it and get out of there. Right. Why should someone come to UVA Pulmonary and Respiratory for treatment?

Dr. Gomez:  One thing I wanted to add, in terms of management, the therapy.

Bill: Okay. Go ahead.

Dr. Gomez:  There is some medication called Prednisone that sometimes we use and it will help the inflammation to come down. What we see on the CT scan is mostly inflammation. It doesn’t take care of the scar tissue but it improves inflammation and that may help the patient to feel a little better. All of the medications because it is an inflammatory condition. You want to fight the immune system, it weakens the immune system. The ongoing inflammation may be taken care of by all of the medications. What I mean by that is there is something called Isoptin or Mycophenolate that we usually try. Those take care of the inflammation so that we don’t have to use the prednisone in the long term. We don’t think it is a good medication chronically because it has so many side effects and those include diabetes, high blood pressure and other problems.

Bill: It’s good to know that there are ways that you can relieve some of the symptoms with somebody with HP.

Dr. Gomez:  Right.

Bill:  So, why should someone come to UVA Pulmonary and Respiratory for their treatment?

Dr. Gomez: I think the main reason why people should come to UVA is because we have very experienced physicians that we have seen many cases and then we know how to approach this condition and how to get the patient’s work up. We have all the resources that the patient needs to come up with a diagnosis and then therapy for them. It is a very experienced team and we’ll do what’s best for the patient.

Bill:  That sounds great. Dr. Diana Gomez, thank you so much for being on with us today. We really appreciate it. For more information please visit UVAHealth.com. That’s UVAHealth.Com. I’m Bill Klaproth in for Melanie Cole. This is UVA Health Systems Radio. Thanks for listening.