Pneumocystis pneumonia

Pneumocystis pneumonia

Updated: 08/12/2025

© Jun Wang, MD, PhD

 

General features

  • Caused by the fungus Pneumocystis jirovecii
  • May occur in any immunocompromised patients, such as those with primary immunodeficiency
  • One of the most common AIDS defining diseases
  • Likely airborne transmission
  • High mortality and morbidity

Pathogenesis

  • Inhaled pneumocystis attach to alveolar wall
  • Macrophages could not eradicate pneumocystis due to lack of CD4+ lymphocytes
  • Local inflammation results in alveolar injury

Clinical presentations

  • Chills, fever, nonproductive cough, difficulty breathing, chest pain, fatigue

Radiological findings

Pathological features

Diagnosis

  • Identification of pneumocystis jirovecii in bronchoalveolar lavage, sputum, or lung biopsy
  • PCR

Managements

  • Trimethoprim and sulfamethoxazole

 

 

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Contents

Pathology notes Jun Wang, MD, PhD 1. General information Frequently discussed syndromes Terms of dermatology Terms of hematology 2. Immunodeficiency disorders HIV infection   Primary immunodeficiency disorders 3. Hemodynamic abnormalities Shock Thrombosis and embolism Bleeding disorders Blood transfusion 4.  Benign blood cell disorders Anemia Benign white cell disorders 5. Hematopoietic neoplasms Lymphoid neoplasms Myeloid neoplasms Histiocytic neoplasms: Langerhans cell histiocytosis 6. Cardiovascular system Pulmonary hypertension Cardiovascular system tumors 7. Respiratory tract tumors 8. Gastrointestinal tract Congenital disorders Infectious gastroenteritis Oral cavity Esophagus Stomach Intestinal tumors Salivary glands Exocrine pancreas and gallbladder 9. Urinary system Kidney masses Lower urinary tract 10. Male reproductive system 11. Female genital tract 12. Breast 13. Endocrine organs Pituitary gland Ad...
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Anemia

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Bleeding disorders

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