Pneumocystis pneumonia, often referred to by the acronym PCP, is a life-threatening condition in which fluid builds up in the lungs and causes inflammation.
PCP is caused by a tiny fungus called Pneumocystis jirovecii which is common in the environment. Pneumocystis pneumonia has a long history, dating back to 1909. In the 1940s and 1950s, pneumocystis pneumonia was the cause of pneumonia epidemics affecting premature and malnourished infants.
In the 1980s, PCP became the leading cause of death among people with AIDS. To date, the majority of cases of PCP are seen in people with the human immunodeficiency virus (HIV), but this fungus also affects people with other underlying medical conditions.
Most humans are exposed to Pneumocystis jirovecii fungus in childhood. In healthy children, it often develops with cold symptoms and does not develop into anything serious.
Pneumocystis jirovecii spreads in the air. While most people have robust immune systems that can defend themselves against this fungus, those with weakened immune systems may be unable to fight off this infection.
This article discusses the risk factors, symptoms, diagnosis, treatment, and prevention of PCP.
PCP can be a life-threatening disease for people with weakened immune systems. Certain conditions and medications can increase your risk of PCP, including, but not limited to:
- Previous Pneumocystis jirovecii infection
- Cancer, especially cancers that affect the blood, such as leukemia
- Organ transplant
- Stem cell transplant
- Rheumatic diseases
- Immunosuppressive drugs
- Severe malnutrition
Those with low blood CD4 cell counts are most at risk of pneumocystis pneumonia. While CD4 levels are often tested in people with HIV, they are also checked in people with the above conditions.
Oral thrush is a fungal infection that primarily affects the mouth and throat. A study shows that those who suffer from oral thrush have almost a 30% chance of developing a PCP infection within 6 months.
Symptoms of pneumocystis pneumonia can vary between those of people living with HIV and those of people with cancer or taking immunosuppressive drugs. Symptoms of pneumocystis pneumonia appear gradually in many people, and it may take weeks before you notice symptoms appearing.
Most common symptoms
- Feel like you can’t breathe deeply
- Dry cough
- Sudden, sharp chest pain
- Malaise (general feeling of being unwell)
PCP is not always the most obvious disease to diagnose. It can begin by mimicking the same symptoms as a cold or flu, which is why additional tests are needed to diagnose PCP.
Your healthcare provider will start by discussing your symptoms. The doctor will use a stethoscope to listen for anything unusual in your lungs.
After your medical exam, you will likely need a chest X-ray to see if there is an infection in your lungs. However, an X-ray is not always conclusive when it comes to PCP. In fact, a chest X-ray may appear normal in up to 25% of patients diagnosed with PCP.
If your healthcare provider suspects a PCP infection but you have an x-ray that looks normal, they may order a computed tomography (CT) scan. A CT scan is able to provide a better picture of the lungs than an X-ray.
Because a CT scan will expose you to more radiation than an X-ray and will also cost more, your provider will start with an X-ray first.
Induced sputum test
The surest way to diagnose PCP is by sputum culture.
During this test, you will breathe in a salt water mist that will cause you to cough up mucus from your lungs. Once a sample has been taken, it will be sent to a laboratory. In the laboratory, the sample will be observed under a microscope to look for the fungus.
A bronchoalveolar lavage is another way to collect sputum. It uses a bronchoscope to take a sample from the lungs and, according to several sources, is common and useful in the diagnosis of fungal infections, especially in differentiating between Pneumocystis jirovecii and other mushrooms.
Pulmonary Function Test (PFT)
After you are diagnosed with PCP, you will have a lung function test to see how well the lungs are working.
A PFT looks at how much air you breathe in and out, how fast you exhale, and how much oxygen moves from your lungs to your blood.
There are several options for treating PCP. The treatment you receive will depend on many factors, including the severity of your symptoms and whether or not you need hospitalization.
If you have a mild case of PCP, you can treat yourself at home by taking prescription medications such as Bactrim. If your case falls into the moderate category, you will be given a prescription steroid to help reduce inflammation and damage in your lungs.
While some people are successful in treating PCP at home, many others need to be treated in hospital. While in the hospital, you will receive hydration and medication through an intravenous (IV) infusion. You will likely receive supplemental oxygen; in severe cases, you will be put on a ventilator.
Most treatment plans for PCP will last about three weeks. Many people will begin to feel better within four to seven days of starting treatment. However, how quickly you will feel better will depend on:
- How strong is your immune system
- How severe is your infection
- How quickly you start treatment
During recovery, it is essential to stay hydrated, get enough rest, and avoid other sick people. The last thing you want to do when fighting PCP is get another infection.
PCP and cough medicine
While it seems reasonable to take cough medicine, it’s important to only take cough medicine at night when you’re trying to get a full night’s rest. Coughing is an important mechanism your body uses to get rid of a lung infection. If you don’t cough at all, your lungs can’t get rid of the mucus and the infection only gets worse.
PCP can be harder to prevent than other forms of pneumonia. Prevention is based on following all recommendations from your health care provider. If you have HIV, taking anti-HIV drugs is essential to keep your CD4 count above 200.
Nutrition is key to keeping your immune system strong. Healthy eating involves consuming protein at every meal, as well as foods containing vitamins and minerals. Protein helps your body repair damaged cells and keep existing cells healthy.
Many drugs interact badly with drugs. In some cases, alcohol interferes with the medications you are taking. When you’re sick, it’s crucial to avoid alcohol in order to give your body and medications a chance to function at their full capacity.
Keeping your mental health in check is essential. Chronic or excessive stress, anxiety and depression will weaken your immune system. Even the slightest improvement in your stress levels can dramatically improve your body’s ability to fight off any infection, including pneumonia.