Can Asthma Cause Pneumonia?

Female patient talking with doctor
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Not long ago, I had a patient walk into my office complaining that they had asthma pneumonia. Not remembering asthma pneumonia as a disease I had learned about in medical school, I asked her what she meant by this condition. In talking with her, this long-term asthma patient thought her asthma had caused pneumonia for which she was seeking treatment. After her visit, I realized a number of patients have asked me two similar questions about asthma pneumonia over the years:

  1. Can asthma cause pneumonia?
  2. Can pneumonia cause asthma?

Can Asthma Cause Pneumonia?

While the exact relationship between asthma and pneumonia is currently debated and under study, there is an FDA warning that pneumonia may be a potential side effect of some drugs used in asthma treatment. In clinical studies using inhaled steroids for COPD, pneumonia occurred twice as commonly in patients on inhaled steroid/LABA combination compared to patients on LABAs alone. However, it is important to realize that many of the cases of pneumonia occurred in patients over the age of 65, and studies have not seen similar increases in pneumonia in patients using inhaled steroids for asthma.

While you need to be mindful of this potential risk, it does not mean you should stop taking your asthma medication.

Can Pneumonia Cause Asthma?

Scientists are beginning to understand the relationship between infections that cause pneumonia and worsening asthma symptoms or the development of asthma.

There is a tremendous amount of interest in an atypical bacteria called Mycoplasma pneumoniae that is most commonly responsible for walking pneumonia. Typically, this infection is thought to be self-limited, meaning that symptoms will resolve even if you are not treated with antibiotics. Scientists, however, have discovered that infection with Mycoplasma pneumoniae causes the following in animals:

  • Chronic infection: While thought to be self-limited, scientists continue to find evidence of the infection in the lungs of animals many months after the infection.
  • Chronic inflammation of the lungs: In mice studies, a single infection with Mycoplasma pneumoniae led to inflammation of the lungs for up to 18 months.
  • Abnormal pulmonary function tests: Over the same time period, scientists found evidence of both obstruction and hyperreactivity of the airways.

There is additional evidence of a relationship of asthma pneumonia in humans. Scientists have found evidence for Mycoplasma pneumoniae both causing an asthma exacerbation and for patients having this infection developing asthma. In particular, scientists have found:

  • Mycoplasma pneumoniae is more commonly identified among hospitalized asthmatics compared to patients hospitalized for other reasons.
  • Mycoplasma pneumoniae is commonly detected in children having an asthma exacerbation.
  • As many as 40% of kids infected with Mycoplasma pneumoniae will have wheezing and abnormal pulmonary function tests.
  • Children with asthma and Mycoplasma pneumoniae infection may be more likely to have abnormal pulmonary function tests both 3 months and 3 years following an infection.
  • Children exposed to Mycoplasma pneumoniae have higher levels of some markers scientists use in studying asthma called vascular endothelial growth factor (VEGF) compared to children without asthma. The association of VEGF and Mycoplasma pneumoniae suggests that the two are linked.

Asthma, Flu, and Pneumonia

You are more likely to hear about flu and pneumonia when flu is impacting your community but pneumonia is a known side effect of an influenza infection. While you are not at increased risk for developing a flu infection because you have asthma, you are at increased risk of developing a side effect such as pneumonia.

Your airways already have some degree of inflammation, swelling, and are more sensitive than those without asthma. A flu infection just makes the swelling and inflammation worse.

Normally your body filters out viruses and bacteria when they enter your body. The increased inflammation increases the chances that the flu virus is not removed and causes you problems. When the flu virus enters the alveoli or breathing sacs in your lung, the alveoli can fill up with fluid that leads to the symptoms of pneumonia such as chills, cough, fever, and trouble breathing.

If enough fluid builds up it can also lead to hypoxia or a decreased oxygen level in the blood. This will usually require hospitalization.

The flu virus can directly cause pneumonia or you could develop a bacterial pneumoia that requires antibiotic treatment. When you have the flu you need to consider treatment. However, the best treatment is to get a flu immunization and prevent it all together.

If you do get a flu infection, your doctor may want to treat yours with an antiviral. These drugs can decrease symptoms and may prevent more severe complications like pneumonia. Antivirals require a prescription from your physician.

Asthma Pneumonia - What About Antibiotics?

Given all of this, you may be wondering if asthmatics with an asthma exacerbation should be regularly treated with antibiotics. Despite what we have previously discussed, there are no current recommendations to prescribe antibiotics for asthmatic patients. A 2006 trial of an antibiotic treating Mycoplasma pneumoniae compared to placebo found improvement of asthma symptoms, but not lung function. While an area of study, there are no current recommendations to treat chronic asthma or asthma exacerbations with antibiotics.


FDA Safety Information. Advair Diskus (fluticasone propionate and salmeterol inhalation powder)

Sutherland ER, Martin RJ. Asthma and Atypical Bacterial Infection. Chest 2007; 132:1962-66.

Hong SJ. The Role of Mycoplasma pneumoniae Infection In Asthma. Allergy, Asthma, and Immunology Research 2012; 4:59-61.

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