Pneumocystis Pneumonia

Pneumocystis Pneumonia

Healthy Lungs
Diseases & Conditions
Contributed byKrish Tangella MD, MBADec 26, 2018

What are the other Names for this Condition? (Also known as/Synonyms)

  • PCP (Pneumocystis Carinii Pneumonia)
  • PJP (Pneumocystis Jirovecii Pneumonia)
  • Pneumocystosis 

What is Pneumocystis Pneumonia? (Definition/Background Information)

  • Pneumocystis Pneumonia is a lung infection caused by a yeast-like fungus called Pneumocystis jirovecii  (that was earlier known as Pneumocystis carinii)
  • Pneumocystis Pneumonia is an opportunistic infection, occurring in individuals with HIV/AIDS, cancer patients undergoing chemotherapy, and organ transplant recipients on immunosuppressive drugs
  • The common signs and symptoms associated with Pneumocystis Pneumonia include fever, non-productive cough, and an increased respiratory rate. The infection may be diagnosed through a physical exam, chest x-ray, sputum examination, and bronchoalveolar lavage
  • Pneumocystis Pneumonia is treated with antibiotics. It is a life-threatening infection that needs early and effective treatment

Who gets Pneumocystis Pneumonia? (Age and Sex Distribution)

  • Pneumocystis Pneumonia can occur at any age depending upon the risk factors
  • There is no gender predilection and both males and females may be affected
  • The condition is observed worldwide; all racial and ethnic groups may be affected

What are the Risk Factors for Pneumocystis Pneumonia? (Predisposing Factors)

Following are the risk factors associated with Pneumocystis Pneumonia:

  • Premature birth
  • Malnutrition
  • Post organ transplantation individuals on immunosuppressants (medications)
  • Pneumocystis Pneumonia is most commonly associated with AIDS-affected individuals
  • Cancer patients on chemotherapy drugs

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider. 

What are the Causes of Pneumocystis Pneumonia? (Etiology)

Pneumocystis Pneumonia is caused by a fungus named Pneumocystis jiroveci. Individuals may be infected by inhaling the fungal spores from the environment.

  • Generally, individuals with a healthy immune system carry the fungus in their lungs, but do not develop any signs and symptoms. When the immune system weakens (due to a variety of health conditions or reasons), the fungus starts growing in the body, especially in the lungs, resulting in the signs and symptoms
  • Pneumocystis Pneumonia is a serious (opportunistic) infection in those with poor immune systems (those who are immunocompromised) and is present in higher numbers among AIDS patients. It does not affect the normally healthy people

What are the Signs and Symptoms of Pneumocystis Pneumonia?

The signs and symptoms associated with Pneumocystis Pneumonia include:

  • Fever: Pneumocystis Pneumonia infection causes low-grade fever in a HIV-infected individual, whereas in a HIV-uninfected individual, the fever is usually high
  • Non-productive cough
  • Dyspnea (labored breathing)
  • Tightness of chest
  • Tachypnea (increased respiratory rate) over a period of weeks to months
  • Crackles (abnormal sounds heard upon examination of the lungs)

How is Pneumocystis Pneumonia Diagnosed?

The diagnosis of Pneumocystis Pneumonia may include:

  • Complete evaluation of medical history along with a thorough physical exam
  • The sputum is examined under a microscope to detect the presence of pathogens
  • Chest x-ray, to assess the extent of lung involvement
  • CD4 cell count: In immune-compromised patients,  if the CD4 count is less than 20, then there is a high likelihood of acquiring the infection
  • Bronchoalveolar lavage: The lung and airways are examined with the help of a scope. Simultaneously, a tissue sample is taken from the lungs and sent to the laboratory for examination under a microscope by the pathologist
  • Lung function test to help examine the structure and the efficiency of the lungs

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis. 

What are the possible Complications of Pneumocystis Pneumonia?

The possible complications associated with Pneumocystis Pneumonia are:

  • Pleural effusion: Presence of fluid in the space between the lungs and chest wall
  • Pneumothorax: Presence of air in the space between the lungs and chest wall
  • Respiratory failure
  • If not treated early and promptly, Pneumocystis Pneumonia may result in death.

How is Pneumocystis Pneumonia Treated?

The treatment of Pneumocystis Pneumonia may involve:

  • The infection is treated with medications, which are either given orally or intravenously
  • Supportive therapy may include oxygen therapy, medications for fever, and fluids

How can Pneumocystis Pneumonia be Prevented?

Preventive measures for Pneumocystis Pneumonia may include administering prophylactic therapy to the following ‘at risk’ individuals:

  • AIDS patients with CD4 cell count less than 200
  • Organ transplant patients
  • Bone marrow transplant patients
  • Patients with previous episode of the infection
  • Individuals on long-term high-dose steroids

What is the Prognosis of Pneumocystis Pneumonia? (Outcomes/Resolutions)

  • Pneumocystis Pneumonia is a life-threatening infection that needs early and effective treatment
  • It has an increased probability for recurrence. The severity of the condition increases with each episode of the infection; each time the disease causes more severe damage to the lungs and other body organs

Additional and Relevant Useful Information for Pneumocystis Pneumonia:

The following DoveMed website link is a useful resource for additional information:

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Krish Tangella MD, MBA

Pathology, Medical Editorial Board, DoveMed Team


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