Fungal Pneumonia

What is fungal pneumonia?

Fungal pneumonia is a rare type of lung infection caused by fungi. It usually occurs in residents or travelers to endemic areas, in which case it is usually mild, but in individuals with impaired immunity it can be life-threatening.

Symptoms

If you have fungal pneumonia you can experience a dry cough or coughing up blood, low-grade fever, night sweets, headache, chest pain during deep breathing and weight loss ^[1,3].

Risk Factors and Causes

Fungal pneumonia often occurs in individuals with impaired immunity due to HIV/AIDS, long-term steroid therapy for sarcoidosis or chronic bronchitis, chemotherapy for leukemia or lymphoma, immunosuppressant therapy associated with organ transplantation or low white blood cell count (leukopenia, neutropenia) ^[1].

Inhalation of the Aspergillus fungi from outdoor or indoor sources, such as decomposed plants, soil or dust, can cause invasive pulmonary aspergillosis ^[2,3] or chronic necrotizing pulmonary aspergillosis ^[3].

Inhalation of the Histoplasma fungi from bird and bat droppings in the soil, caves, chicken cops and construction sites can cause acute or chronic pulmonary histoplasmosis ^[4].

Inhalation of the yeast Cryptococcus from bird droppings in the soil can cause cryptococcal pneumonia ^[7].

The fungus Pneumocystis jiroveci (formerly considered a parasite with the name Pneumocystis carinii) can cause life-threatening pneumonia ^[8]. Infection usually occurs in persons with impaired immunity due to HIV/AIDS by multiplying of the fungi that are normally present in the lungs (opportunistic infection) ^[8]. Pneumocystis jirovecii can also spread from person to person by coughing and sneezing ^[2].

Inhalation of the Coccidioides fungi from soil, mainly in summer and fall, can cause pulmonary coccidioidomycosis or Valley fever in residents, farmers, construction workers and travelers to San Joaquin Valley of California, Arizona and Mexico ^[9,10].

Inhalation of the Mucor fungi can cause pulmonary mucormycosis with a high mortality rate, mainly in individuals with poorly treated diabetes mellitus with ketoacidosis ^[11].

Other fungi that can cause pneumonia:

• Blastomyces
• Candida
• Cryptococcus
• Sporothrix

Is fungal pneumonia contagious?

Fungi that cause pneumonia rarely spread from person to person; you more likely inhale the fungi from the environment or from your own mouth, nose or throat. If you are healthy and you are in close contact with someone who has fungal pneumonia, you will not likely get pneumonia.

The incubation period for fungal pneumonia can range from 3 days to more than 3 weeks ^[4].

Diagnosis

A doctor can make a diagnosis of fungal pneumonia from:

• Microbes in the culture of the coughed up mucus (sputum)
• Specific antibodies in the blood
• White shadows (bronchopneumonia), rounded shadows (fungal balls) or cavities on an X-ray film ^[1,12].

In uncertain cases, lung biopsy may be needed.

Differential Diagnosis

Diseases that can mimic fungal pneumonia:

• Viral pneumonia
• Atypical pneumonia
• Tuberculosis
• Chemical worker’s lung
• Coal worker’s pneumoconiosis
• Pneumonitis

Treatment

Fungal pneumonia can be treated with antifungal drugs, depending on the cause:

• Aspergillosis: voriconazole, itraconazole, amphotericin B ^[5]
• Histoplasmosis: itraconazole, amphotericin B, surgery ^[6]
• Cryptococcosis; amphotericin B, flucytosine, fluconazole ^[7]
• Pneumocystis jirovecii pneumonia: trimethoprim-sulfamethoxazole, corticosteroids ^[8]
• Coccidioidomycosis: itraconazole, and fluconazole ^[10]
• Mucormicosis: amphotericin B plus surgery ^[11]

Complications and Prognosis

Fungal pneumonia in otherwise healthy travelers to endemic areas is usually mild ^[4,10] but in individuals with impaired immunity can be life-threatening ^[1].

Complications include ^[1]:

• Chronic pneumonia
• Spread to other organs: brain (encephalitis), meninges (meningitis), skin, liver, spleen or kidneys.
• Death

• References

  1. Mandanas RA, Fungal pneumonia  Emedicine
  2. Bennett NJ, Pneumocystis jiroveci Pneumonia Overview of Pneumocystis jiroveci Pneumonia  Emedicine
  3. Harman EM, Aspergillosis  Emedicine
  4. Fayyaz Y, Histoplasmosis  Emedicine
  5. Harman EM, Aspergillosis Treatment & Management  Emedicine
  6. Fayyaz Y, Histoplasmosis, treatment  Emedicine
  7. King JW, Cryptococcosis  Emedicine
  8. Pneumocystis jirovecii pneumonia  Emedicine
  9. Hospenthal DR, Coccidioidomycosis  Emedicine
  10. Hospenthal DR, Coccidioidomycosis, clinical presentation  Emedicine
  11. Muqeetandan M et al, 2012, Pulmonary Mucormycosis: An Emerging Infection  Hindawi
  12. Franquet T et al, 2011, Imaging of Pulmonary Viral Pneumonia  Radiology Society of North America