What Is Multifocal Pneumonia?

In the most general of terms, pneumonia is an infection in the lungs caused by inflammation of the air sacs, known technically as alveoli. Those alveoli fill up with fluid or pus, which leads to symptomslike coughing, fever, and chills.

But pneumonia can be much more complicated than that—it can be caused by different things (a virus, bacteria, or fungus), acquired in different environments (in the community or at the hospital), and can even differ in how much the infection affects the lungs.

Multifocal pneumonia narrows the diagnosis down a little more to how much of the lung is affected. Essentially, multifocal pneumonia is a term that's used to describe pneumonia in different spots of the lung, Raymond Casciari, MD, a pulmonologist and chief medical officer at St. Joseph Hospital in Orange, Calif., told Health. "Multifocal could be two spots in the same lobe or two spots in different lobes," Casciari said.

To better understand what multifocal pneumonia is, you first need to know a bit about lung biology. Your lungs are made up of sections known as lobes that are like small balloons filled with sponge-like tissue. Your right lung is divided into three lobes, and your left lung has two lobes.

Healthcare providers can further break down multifocal pneumonia by calling it unilateral multifocal pneumonia and bilateral multifocal pneumonia, Shweta Sood, MD, a pulmonary medicine physician and assistant professor of clinical medicine at Penn Medicine, told Health. "Unilateral pneumonia refers to pneumonia only affecting one lung—right or left," explained Dr. Sood. "Bilateral pneumonia tends to affect both lungs."

Causes of Multifocal Pneumonia

Technically, multifocal pneumonia can be caused by the same things that cause other types of pneumonia—viruses, bacteria, and fungi. But "if it's multifocal, it's more likely to be caused by a virus, like we've seen with COVID-19," Khalilah Gates, MD, a pulmonary and critical care specialist at Northwestern Medicine, told Health.

Other potential causes of viral multifocal pneumonia include respiratory syncytial virus (RSV) and some common cold and flu viruses.

Multifocal pneumonia can also be caused by bacteria like streptococcus pneumoniae or legionella pneumophila, or fungi such as pneumocystis pneumonia, coccidioidomycosis, or cryptococcus, said Dr. Casciari. "Having multifocal pneumonia doesn't automatically signify what's causing the pneumonia," explained Dr. Casciari. "We still have to investigate."

Symptoms

Symptoms of multifocal pneumonia are usually the same as other types of pneumonia, but "in general, multifocal pneumonia tends to be more severe," said Dr. Casciari.

Symptoms of pneumonia can include:

• Cough
• Fever
• Chills
• Shortness of breath
• Sputum production
• Chest pain when you breathe or cough

"Some patients can be quite sick when they develop multifocal pneumonia," said Dr. Sood. But, Dr. Sood added, "most people may only have mild symptoms and be able to recover at home."

Diagnosis

When a healthcare provider is trying to rule out or confirm a diagnosis of pneumonia, they take medical history, a physical examination, and test results into account.

In terms of medical history, you'll answer questions about symptoms and risk factors for pneumonia. The healthcare provider might also ask if you have been around other sick individuals, your flu and pneumonia vaccination status, and any recent traveling you've done. They will also listen to your lungs and check your temperature during the physical exam.

The tests for diagnosing pneumonia look for different aspects of the illness. Some of the tests the provider might use for diagnosis include:

• Chest x-rays: Indicates if there is lung inflammation
• Blood tests: Determines if the immune system is working against an infection
• Pulse oximetry: Measures blood oxygen levels with a small sensor

Healthcare providers may do several other tests (e.g., sputum tests, blood culture tests, CT scan) to determine if someone has pneumonia—based on if that person has serious symptoms, other health problems, is an older individual, or is hospitalized.

Treating Multifocal Pneumonia

Healthcare providers like to try to catch pneumonia early so that they can treat it appropriately before it progresses too far, Dr. Gates said. But the actual treatment depends on what's causing the pneumonia in the first place. "You've got to find the cause," said Dr. Casciari.

Once healthcare providers figure out what's behind the pneumonia, they'll prescribe a treatment based on that. "For patients with mild symptoms, treatment centers around rest, hydration, and good nutrition," said Dr. Sood.

If the pneumonia is bacterial, the patient will be given antibiotics, said Dr. Sood. He pointed out that "most patients with viral pneumonia do not require antibiotics." Instead, they may be treated with an antiviral medication like Tamiflu (oseltamivir) or Veklury (remdesivir), depending on the cause of the infection.

And, if a patient has fungal pneumonia, it will be treated with antifungal medication, said Dr. Casciari.

The recovery time from pneumonia, in general, may vary by individual. Additionally, a person's overall health matters with recovery from multifocal pneumonia. "Most healthy people with minimal underlying medical conditions usually recover from pneumonia with no issue over the course of several days," said Dr. Sood. "Patients who have underlying medical conditions still may have good recovery, but it may take longer. In very severe cases, pneumonia can cause death."

Still, many people with multifocal pneumonia end up OK. "The main thing about multifocal pneumonia is getting the patient over the acute phase," said Dr. Casciari. If we can [help do that], patients generally do well, and the lungs heal."

A Quick Review

Multifocal pneumonia is a lung infection that appears in more than one area of one or both lungs. Though viruses, bacteria, or fungi can cause it, the illness is most often caused by viruses.

Additionally, symptoms of multifocal pneumonia tend to be more severe than the symptoms of other kinds of pneumonia. Multifocal pneumonia is also diagnosed in similar ways to other pneumonia types, and it can be treated with rest, nutrition, and medications depending on the cause.