What Is Fungal Pneumonia?

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Fungal pneumonia is a type of pneumonia (lung infection) caused by fungal spores in the air, soil, or clinical environments. A noncontagious condition, its symptoms are like those of the flu: coughing, headache, thick mucus, fever, and chest pain, among others.

Generally affecting those with weakened immune symptoms, if untreated, this class of lung infections can become very serious and even deadly.

Several kinds of fungi cause fungal pneumonia, though the three most common are Pneumocystis, Cryptococcus, or Aspergillus. Infection occurs when spores of these fungi are inhaled.

Mother and daughter at the pediatric office

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These types of infections most often occur in those with compromised immunity, such as adults over age 65, children under age 2, or those with chronic diseases, such as human immunodeficiency virus (HIV/AIDs) or cancer. 

Because fungal pneumonia tends to develop in people with already weakened immune systems, treatment can be challenging. That said, there are antifungal medications designed to fight this kind of infection, with itraconazole being most often indicated.

Symptoms

Because the most common symptoms of fungal pneumonia are similar to those of viral or bacterial lung infections, diagnosis—and proper treatment—can be delayed. Those symptoms are:

  • Fever
  • Chills
  • Cough with thick, colored phlegm
  • Shortness of breath
  • Pain while breathing or coughing
  • Nausea and/or vomiting
  • Diarrhea

Age can play a part in the type and severity of symptoms in people with fungal pneumonia, including:

  • In older adults, fungal pneumonia symptoms tend to be mild, but the condition can also lead to mental confusion, which requires immediate medical attention.
  • Infants and toddlers with the condition may have difficulty feeding, pale-colored skin, breathing difficulties (grunts or rattles while breathing), a limp appearance, less urine production, and fussiness.

When to Call a Doctor

If you suspect you have pneumonia or have been diagnosed with it, let your doctor know if you develop the following symptoms:

  • Persistent shortness of breath
  • Lingering fever with heavy mucus
  • Extreme fatigue

Call 911 for emergency help if you or a loved one experience:

  • Breathing difficulties and shortness of breath at rest
  • New or growing chest pain and discomfort
  • Confusion or disordered thinking

Causes

Primarily, fungal pneumonia develops when fungal spores are inhaled. Each form of this disease arises from a corresponding type of fungus that often are native to specific regions. These fungi include:

  • Coccidioides is native to the soil of the American Southwest, as well as parts of Central America and South America.  
  • Histoplasma fungi develop from the droppings of certain bird and bat species typically found in the central and eastern United States, especially in the Ohio and Mississippi river valleys. They also originate in Central America and South America, Africa, Asia, and Australia.
  • Cryptococcus neoformans is found in soil and bird droppings in all parts of the world.
  • Blastomyces lives in rotting wood, leaves, and damp soil in Midwestern, south central, and southeastern states.

In addition to these are opportunistic fungal infections, those that are present in any indoor or outdoor setting, including clinical or hospital environments, called hospital acquired infections (HAIs). Most common among these are the Candida, Aspergillus, and Pneumocystis jirovecii, the latter two of which cause pneumonia.

Overall, these infections are rare in healthy adults and tend to infect people with compromised immunity. These include:

  • Adults age 65 or older
  • Toddlers and infants 2 and younger
  • Human immunodeficiency virus (HIV/AIDs) patients
  • Cancer patients undergoing chemotherapy
  • Patients taking large doses of corticosteroids
  • People with autoimmune disorders (lupus, multiple sclerosis, and others)  
  • Those with hematologic (blood) disorders
  • Bone marrow transplant patients
  • Tobacco smokers

In addition, immunity can be affected by a number of preexisting heart or lung conditions, including:

Types

As noted, there are several types of fungal pneumonias, and while they largely align, symptoms can vary slightly among them. Pneumonia types are categorized based on the fungus that causes the infection.

Pneumocystis Pneumonia

Deriving from the yeast-like Pneumocystis jirovecii fungi, pneumocystis pneumonia causes severe dry cough, fever, and chest pains. It typically impacts those with vulnerable immune systems, like cancer patients and those with HIV, or people who have had a bone marrow transplant or take high doses of corticosteroids.

Since this fungal pneumonia most often arises in already very sick, immunocompromised people, this condition can be very difficult to take on. Treatment may be oral medication or daily IV (intravenous) injections for three weeks. While outcomes are improving, this type of pneumonia is still a major cause of death among HIV/AIDs patients.

Valley Fever

Also known as coccidioidomycosis, valley fever arises from exposure to Coccidioides fungi from soil in the U.S. Southwest, as well as parts of Central America and South America. It usually affects people 60 and older and those exposed to dusty environments, such as farmworkers and construction workers.

Symptoms of this fungal infection—fever, cough, headache, rash, and muscle and joint pain—mimic other illnesses, making diagnosis challenging.

The outlook for people with this condition is brighter than for those with other fungal pneumonias: While treatment is extensive—lasting up to six months—most people respond well to it and recover fully. That said, long-term infections and nerve damage can linger, and untreated cases can be very dangerous.

Histoplasmosis

Caused by the Histoplasma fungus of the central and eastern United States, histoplasmosis causes fatigue, fever, and coughing, as well as other typical pneumonia symptoms. Arising three to 17 days after exposure, many cases resolve on their own, though some cases can become advanced and severe.

In the worst cases, infections spread from the lungs to other parts of the body, such as the spinal cord and brain.

Courses of treatment—taking medications—can last from three to 12 months. Severe cases of this pneumonia can be deadly, and histoplasmosis has a mortality rate of about 4% at six months after hospitalization.

Cryptococcus

This pneumonia is due to exposure to Cryptococcus neoformans, which is found in rotting wood and bird droppings in natural environments. As with other infections, cryptococcus only occurs in people with already weak immune systems, with most healthy individuals being able to fend off this disease.

Typical pneumonia symptoms accompany cases of cryptococcus. If untreated, it can progress to an infection of the brain or spinal cord called cryptococcal meningitis.

Antifungal medication for this condition is taken for at least six months, with fatality estimated to be about 12%. Like pneumocystis pneumonia, this infection was once a major cause of death among HIV/AIDS patients, though these numbers have gone down as therapies improve.

Aspergillosis

Among the most prevalent airborne fungi is Aspergillus, a mold found in many indoor and outdoor environments. The resulting infection, aspergillosis, is often acquired in the hospital setting in patients with severe immunodeficiency. This type, along with cryptococcus and some others, is associated with late-stage HIV/AIDS cases.

In addition to pneumonia symptoms, this type of infection can cause masses known as “fungal balls” (aspergilloma) to grow in the lungs. It can also spread to other organs.

While milder forms of aspergillosis are easily treated and managed with drug therapy, severe cases can be dangerous. Since immunocompromised people are affected, this condition can become deadly. For instance, the one-year survival rate for those with this condition after organ transplant is about 59%.

Diagnosis

One of the main challenges of fungal pneumonia is that it’s a disease that resembles others. Many people delay seeking medical attention, assuming they have a cold or flu. In addition, determining the exact cause requires lab assessment of cultures found in mucus and/or fluid from the lungs.

Diagnosis is made through the following tests:

  • Evaluation: Initial evaluation is an assessment of medical history and symptoms, as well as a physical examination, including a doctor using a stethoscope to listen to your lungs.
  • Chest X-ray: X-ray imaging assesses the buildup of fluid in your lungs, the pattern of inflammation, and the severity of the disease.
  • Blood testing: A blood sample can determine immune system health and your body's reaction to the fungus. Oftentimes, a complete blood count (CBC)—measuring amounts of white and red blood cells, as well as platelets—is ordered.
  • Blood culture: To make sure the infection hasn’t spread from the lungs to other parts of the body, clinical tests of blood samples may be required. The presence of pathogens in the bloodstream warrant particular care.
  • Pulse oximetry: This test, or others checking blood-oxygen levels, may be conducted in advanced cases. Extremely low levels can indicate a medical emergency.

In severe cases, additional tests may be needed, including:

  • Sputum test: To help determine the specific fungi or other cause of infection, a sample of your phlegm (the mucus from your lungs) will need to be clinically tested.
  • Chest computerized tomography (CT) scan: If doctors suspect significant damage to the lungs or the development of complications there, this type of imaging will be called for.
  • Pleural fluid culture: The pleura is the tissue covering each lung and lining the chest cavity. Samples from the fluid surrounding this tissue may be screened for signs of fungi or bacteria.
  • Bronchoscopy: By using an endoscopic device—basically a camera at the end of a retractable tube—doctors can view real-time video of the inside of the lungs and air passages. 

Treatment

Fungal pneumonia is primarily treated with antifungal medications. Specific dosages and methods of administration vary based on the individual case and type of infection. Medications indicated include:

  • Itraconazole: Of a class of antifungal drugs called triazoles, itraconazole is the most common medication indicated for blastomycosis, histoplasmosis, and aspergillosis. Available under the name Sporalax, it’s taken as an oral caplet or liquid.
  • Fluconazole: This triazole, with the trade name Diflucan, is not only used to treat cryptococcal infection and valley fever, it’s also indicated to prevent fungal pneumonia in HIV/AIDS or organ transplant patients. This drug is taken as a tablet or through an IV.
  • Other triazoles: Other drugs of this class may also be prescribed, such as Vfend or Vfend IV (voriconazole), Noxafil (posaconazole), or Cresemba (isavuconazole) for aspergillosis.
  • Amphotericin B injection: Of another class of antifungals called polyenes, these drugs with the brand names Abelcet and Ambisome are taken intravenously daily in severe cases of fungal pneumonia.
  • Trimethoprim/sulfamethoxazole: The combination of these antibiotics, sold under the names Bactrim, Septra, and Cotrim, is often indicated in cases of pneumocystis pneumonia.
  • Echinocandins: Aspergillus infections can be treated by this class of medications, which acts directly on the fungi, preventing them from spreading. Three types may be prescribed: caspofungin, micafungin, and anidulafungin.

In severe cases, oxygen therapy to restore oxygen levels and breathing exercises to loosen mucus and strengthen the lungs may be ordered. In general, the duration of treatment for fungal pneumonia can last up to year.

In very advanced cases of cryptococcus, valley fever, and aspergillosis, fungal growths called mycetomas can form in the lungs and need to be surgically removed. This delicate work is undertaken only if previous therapies haven’t yielded results.

Complications

If the fungal pneumonia progresses, a number of potentially very dangerous complications arise:  

  • Lung abscess: Advanced cases of fungal pneumonia cause pus—viscous, yellowish or green fluid—to collect in the cavities of lungs.
  • Pleural disorders: The pleura can become diseased or inflamed.
  • Pulmonary edema: This condition, caused by the buildup of fluid in the lungs, causes serious breathing difficulties.
  • Respiratory failure: Severe inflammation within the lungs can prevent them from performing their function of bringing in oxygen and removing carbon dioxide, hampering breathing.

If the infection spreads from the lungs to the bloodstream, other parts of the body become vulnerable. This leads to a number of serious conditions, including:

  • Fungal meningitis: If the infection spreads to the cerebrospinal fluid surrounding the brain and spine, fungal meningitis arises. This potentially fatal condition's symptoms include headache, fever, and stiff neck. 
  • Kidney failure: Fungal pneumonia can damage the kidneys, which serve to filter and clean the bloodstream. When damage occurs, harmful waste products can build up in the body.
  • Other organ failure: The liver and spleen also may become damaged as the infection progresses in the body.
  • Cardiac effects: Severe cases of pneumonia can result in heart problems and issues with circulation. In turn, the risk of stroke, heart failure, or heart attack is increased.

Advanced cases of fungal pneumonia of all forms also can lead to mycetomas in the lungs. Aspergilloma, the development of mycetomas as a result of Aspergillus infection, is the most common form, but valley fever, histoplasmosis, and cryptococcus all can cause these kinds of growths.

A Word From Verywell

Fungal pneumonia represents a persistent medical challenge. This type of disease is particularly problematic because it affects people who are already sick, adding to their burden. In addition, this condition often goes unnoticed and untreated, worsening outcomes.

But while there’s plenty of room for concern in the face of this condition, there also is hope. Medicine's understanding of how fungi like Aspergillus, Pneumocystis, and others affect the body—and how to treat them—is expanding. As the research continues, the outlook will only improve.

If you or a loved one has fungal pneumonia, don’t hesitate to seek the medical help you need, learn as much as you can about the condition, and make sure family, friends, and coworkers are ready to help. These efforts combined will help ease the burden of fungal pneumonia. 

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