Pneumonia in an immunocompromised host describes a lung infection that occurs in a person whose ability to fight infection is greatly reduced.

See also:

• Hospital-acquired pneumonia
• Mycoplasma pneumonia
• Pneumonia - cytomegalovirus
• Pneumonia
• Viral pneumonia
• Walking pneumonia

People who are immunocompromised have a defective immune response. Because of this, they are susceptible to infections by germs that typically do not cause disease in healthy people. They are also more vulnerable to the usual causes of pneumonia, which can affect anyone.

Immunosuppression can be caused by:

• Bone marrow transplant
• Certain medications (including steroids and those used to treat cancer)
• HIV infection
• Leukemia
• Organ transplant

• Cough (may be dry or produce mucus-like, greenish, or pus-like sputum)
• Chills with shaking
• Easy fatigue
• Fever
• General discomfort, uneasiness, or ill feeling (malaise)
• Headache
• Loss of appetite
• Nausea and vomiting
• Sharp or stabbing chest pain that gets worse with deep breathing or coughing
• Shortness of breath

Other symptoms that may occur:

• Excessive sweating or night sweats
• Joint stiffness (rare)
• Muscle stiffness (rare)
• Swollen glands

The doctor may hear crackles or other abnormal breath sounds when listening to the chest with stethoscope. Lack of breath sounds can be an important sign, because it may mean there is a buildup of fluid between the chest wall and lung.

Tests may include:

• Arterial blood gases
• Blood culture
• Bronchoscopy
• Chest CT scan (in certain cases)
• Chest x-ray
• Complete blood count
• Lung biopsy (in certain cases)
• Sputum gram stain
• Urine tests (to diagnose Legionnaire's disease)

Antibiotics or antifungal medicines are used, depending on the type of germ that is causing the infection. Patients usually must stay in the hospital, at least during the early stages of the illness.

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

The outcome may be poor if the pneumonia is caused by a virus or fungus, or if the patient is severely immunosuppressed.

• Respiratory failure
• Sepsis
• Spread of the infection
• Death

Call your health care provider if you are immunosuppressed and you have symptoms of pneumonia.

Limit exposure of immunocompromised people to others who are ill.

Moran GJ, Talan DA. Pneumonia. In: Marx J, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 6th ed. Philadelphia, Pa: Mosby Elsevier; 2006: chap 75.

Baldwin Dr, Macfarlane JT. Community-acquired pneumonia. In: Cohen J, Powderly WG, eds. Infectious Diseases. 2nd ed. New York, NY: Elsevier; 2004: chap 34.

Donowitz GR, Mandell GL. Acute pneumonia. In: Mandell GL, Bennett Je, Dolin R, eds. Principles and Practice of Infectious Diseases. 6th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2005: chap 61.

Mandell LA, Wunderink RG, Anzueto A, et al. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis. 2007 Mar 1;44 Suppl 2:S27-72.

American Thoracic Society. Guidelines for the management of adults with hospital-acquired, ventilator-associated, and healthcare-associated pneumonia. Am J Respir Crit Care Med. 2005 Feb 15;171(4):388-416.