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Pneumonia - weakened immune system

Pneumonia in immunodeficient patient; Pneumonia - immunocompromised host; Cancer - pneumonia; Chemotherapy - pneumonia; HIV - pneumonia

Pneumonia is a lung infection. It can be caused by many different germs, including bacteria, viruses, and fungi.

This article discusses pneumonia that occurs in a person who has a hard time fighting off infection because of problems with the immune system. This type of disease is called "pneumonia in an immunocompromised host."

Related conditions include:

Images

Pneumococci organism
Lungs
Respiratory system

Causes

People whose immune system is not working well are less able to fight off germs. This makes them prone to infections from germs that do not often cause disease in healthy people. They are also more vulnerable to regular causes of pneumonia, which can affect anyone.

Your immune system may be weakened or not work well because of:

Symptoms

Symptoms may include:

Other symptoms that may occur:

Exams and Tests

Your health care provider may hear crackles or other abnormal breath sounds when listening to your chest with a stethoscope. Decreased volume of breath sounds is a key sign. This finding may mean there is a buildup of fluid between the chest wall and lung (pleural effusion).

Tests may include:

Treatment

Antibiotics or antifungal medicines may be used, depending on the type of germ that is causing the infection. Antibiotics are not helpful for viral infections, but newer medicines may treat some viral infections for example COVID-19. You may need to stay in the hospital during the early stages of the illness.

Oxygen and treatments to remove fluid and mucus from the respiratory system are often needed.

Outlook (Prognosis)

Factors that may lead to a worse outcome include:

Possible Complications

Complications may include:

When to Contact a Medical Professional

Contact your provider if you have a weakened immune system and you have symptoms of pneumonia.

Prevention

If you have a weakened immune system, you may receive daily antibiotics to prevent some types of pneumonia.

Ask your provider if you should receive the influenza (flu), pneumococcal (pneumonia), and COVID-19 vaccines.

Practice good hygiene. Thoroughly wash your hands with soap and water:

Other things you can do to reduce your exposure to germs include:

Related Information

Immune response
Community-acquired pneumonia in adults
Immunodeficiency disorders
Cancer

References

Blijlevens NMA, van der Velden WJFM. Infections in the immunocompromised host: general principles. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 305.

Perkins J, Waasdorp CP. The immunocompromised patient. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 182.

Sifri CD, Marr KA. Approach to fever and suspected infection in the immunocompromised host. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 265.

Wunderink RG, Restrepo MI. Pneumonia: considerations for the critically ill. In: Parrillo JE, Dellinger RP, eds. Critical Care Medicine: Principles of Diagnosis and Management in the Adult. 5th ed. Philadelphia, PA: Elsevier; 2019:chap 40.

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Review Date: 5/19/2023  

Reviewed By: Jatin M. Vyas, MD, PhD, Associate Professor in Medicine, Harvard Medical School; Associate in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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