Pulmonary aspergillosis (PA) is any lung condition that stems from the Aspergillus fungus. There are several forms of pulmonary aspergillosis, including allergic, chronic, and invasive.

These conditions tend to affect people with existing lung problems or those with a compromised immune system.

Pulmonary aspergillosis is a lung disease that arises from Aspergillus spores entering the respiratory system.

While doctors can successfully treat some forms of PA, this is not the case for all.

This article provides an overview of this condition before detailing its symptoms, causes, and possible complications. It will also discuss the diagnosis, treatment, and outlook for PA.

a doctor is listening to a patient's lungs with a stethoscopeShare on Pinterest
FG Trade/Getty Images

As the Centers for Disease Control and Prevention (CDC) explain, aspergillosis is any condition that results from a person inhaling spores of the Aspergillus fungus.

When this condition affects a person’s lungs, scientists and doctors call it “pulmonary aspergillosis.”

Aspergillosis can develop in several ways. The following are all forms of PA:

  • Allergic PA: This condition is when the immune system responds to Aspergillus spores, despite there being no Aspergillus infection. The result is an allergic reaction.
  • Chronic PA: This condition is when an Aspergillus infection settles in the lungs, sometimes for several months. It can create cavities within the lungs, as well as aspergillomas, which are balls of Aspergillus fungus.
  • Invasive PA: Also known as invasive aspergillosis, this condition is a serious form of Aspergillus infection that has the capacity to spread beyond the lungs.

Aspergillus is a common form of mold that lives both indoors and outdoors. Most people breathe in Aspergillus spores every day and do not become sick.

If Aspergillus spores do create illness, its effects can range from mild to severe.

According to the CDC, all forms of PA cause a cough and shortness of breath.

However, the various types of PA can also manifest differently. For instance, further symptoms of allergic PA include:

Contrastingly, further symptoms of chronic PA include:

Finally, invasive PA can present with the following additional symptoms:

If invasive PA spreads to other body parts, it can cause nonpulmonary symptoms. For instance, if the infection reaches the brain, a person can develop neurological symptoms.

Scientists define Aspergillus as a form of fungus.

More specifically, Aspergillus is a mold that commonly lives both in the home and outdoors. It may be impossible to completely prevent these spores from entering the lungs. People breathe in many every day.

Inhaled Aspergillus spores will not necessarily cause PA. As a 2023 review explains, when these spores do cause PA, the pathway is different for each PA subtype:

  • Allergic PA: This condition develops when the body mistakenly responds to Aspergillus spores as though they have created an infection.
  • Chronic PA: This condition develops when lung damage from a preexisting disease allows Aspergillus to colonize the lungs. These diseases include chronic obstructive pulmonary disease (COPD), tuberculosis, and asthma.
  • Invasive PA: This condition develops due to the immune system being unable to fight an Aspergillus infection. For this reason, invasive PA is most common in immunocompromised people.

It is worth noting that some people may have both chronic and invasive PA.

PA can cause a variety of possible complications. According to the above 2023 review, these include:

Some of these complications, such as respiratory failure, CNS infection, and endocarditis, can be fatal.

Given the potential severity of some PA complications, it is important that a person with this condition receives a prompt diagnosis.

As the CDC explain, doctors may need to consider a wide range of factors in order to diagnose this condition. These include:

  • medical history
  • the presence of any PA risk factors
  • the presence of any PA symptoms
  • physical examinations
  • radiographic findings

One complicating factor is that the PA risk factors can sometimes mask symptoms of PA.

For instance, allergic PA is common in people with asthma, which shares symptoms with that condition. Similarly, COPD has symptoms in common with chronic PA, for which it is a risk factor.

Given the uncertainty that can surround PA, doctors may recommend laboratory tests. These tests can help determine whether someone has an Aspergillus infection or is having an allergic reaction to its spores.

Doctors may want to do a blood or skin test or test a sample of fluid from the person’s lungs. In other cases, they may recommend testing a sample of lung tissue.

After doctors have made a PA diagnosis, they can move on to treatment.

As a 2020 review explains, treatment varies with PA sub-type.

Allergic PA

The first line of treatment for allergic PA may involve taking oral steroids such as prednisone or predisolone. Doctors can taper this medication over 3–5 months, depending on the person’s response.

Some experts also include antifungal medications, such as itraconazole.

Chronic PA

Treatment for chronic PA can vary. Stable or simple cases of aspergillosis may not require treatment.

Others can need antifungal medication, surgery, or both. If surgery is not an option, doctors may recommend embolization to treat hemoptysis, which is when a person coughs up blood from the lungs.

Embolization involves blocking one or more blood vessels and is a minimally invasive treatment.

Invasive PA

Doctors may recommend antifungal therapy with voriconazole or isavuconazole for invasive PA.

They can add another type of antifungal medication — echinocandin — if the case of invasive PA is severe or if the person has certain blood issues, such as cancer forming in the bloodstream or neutropenia.

Neutropenia is when someone has a low number of a specific type of white blood cell — neutrophils — in the blood.

The outlook for PA depends on what form this condition has taken.

Evidence suggests that treatment for allergic PA is effective, especially if it begins during the earlier stages of the disease.

However, delays in treatment can mean that people with allergic PA may require steroidal drugs for an extended period. Delays also increase the risk of lung fibrosis.

Contrastingly, the outlook for people with invasive PA is much worse.

Even with antifungal therapy, invasive PA has a 20% mortality rate within 6 weeks of diagnosis. If the infection spreads to the CNS, this figure rises to nearly 100%.

Many people will breathe in Aspergillus spores without developing PA.

For people with conditions such as asthma and COPD, and for people with a weakened immune system, these spores can cause a range of health problems.

The three main forms of PA are allergic, chronic, and invasive.

Doctors can successfully treat allergic and chronic PA, although a full and quick recovery may be difficult. It is much harder to treat invasive PA, which is fatal in a large proportion of cases.