Pneumocystosis
| Pneumocystosis | |
|---|---|
| Other names | Pneumocystis jiroveci pneumonia,[1] Pneumocystis pneumonia,[2] PCP, Pneumocystis carinii pneumonia[3] |
| File:Pneumocystis.jpg | |
| Pneumocystis jirovecii cysts | |
| Specialty | Infectious diseases[1] |
| Symptoms | |
| Complications |
|
| Types |
|
| Causes | Pneumocystis jirovecii[1] |
| Risk factors | Poor immunity, HIV/AIDS[4] |
| Diagnostic method | Medical imaging, bronchoalveolar lavage, immunofluorescence assay, biopsy[2] |
| Prevention | Trimethoprim/sulfamethoxazole (co-trimoxazole) in high risk groups[7] |
| Medication | Trimethoprim/sulfamethoxazole (co-trimoxazole)[4] |
| Frequency | Uncommon,[4] 97% in lungs[7] |
Pneumocystosis is a fungal infection that most often presents as Pneumocystis pneumonia in people with HIV/AIDS or poor immunity.[1][7] It usually causes cough, difficulty breathing and fever, and can lead to respiratory failure.[4] Involvement outside the lungs is rare but, can occur as a disseminated type affecting lymph nodes, spleen, liver, bone marrow, eyes, kidneys, thyroid, gastrointestinal tract or other organs.[5][7] If occurring in the skin, it usually presents as nodular growths in the ear canals or underarms.[3] It is caused by Pneumocystis jirovecii, a fungus which is usually breathed in and found in the lungs of healthy people without causing disease, until the person's immune system becomes weakened.[7] Diagnosis is by identifying the organism from a sample of fluid from affected lungs or a biopsy.[3][4] Prevention in high risk people, and treatment in those affected is usually with trimethoprim/sulfamethoxazole (co-trimoxazole).[4][8] The prevalence is unknown.[7] Less than 3% of cases do not involve the lungs.[7] The first cases of pneumocystosis affecting lungs were described in premature infants in Europe following the Second World War.[9]
Signs and symptoms
Pneumocystosis is generally an infection in the lungs.[4] Involvement outside the lungs is rare but, can occur as a disseminated type affecting lymph nodes, bone marrow,[5][7] liver[5][10] or spleen.[5][11] It may also affect skin,[3] eyes,[12] kidneys, thyroid, heart, adrenals and gastrointestinal tract.[5][13]
Lungs
When the lungs are affected there is usually a dry cough, difficulty breathing and fever, usually present for longer than four weeks.[2][7] There may be chest pain, shivering or tiredness.[8] The oxygen saturation is low.[2] The lungs may fail to function.[4]
Eyes
Pneumocystosis in eyes may appear as a single or multiple (up to 50) yellow-white plaques in the eye's choroid layer or just beneath the retina.[12] Vision is usually not affected and it is typically found by chance.[12]
Skin
If occurring in the skin, pneumocystosis most often presents as nodular growths in the ear canals of a person with HIV/AIDS.[3][6] There may be fluid in the ear.[6] Skin involvement may appear outside the ear, usually palms, soles or underarms; as a rash, or small bumps with a dip.[6] It can occur on the face as brownish bumps and plaques.[6] The bumps may be tender and the ulcerate.[3] Infection in the ear may result in a perforated ear drum or destruction of the mastoid bone.[6] The nerves in the head may be affected.[6]
Cause
Pneumocystosis is caused by Pneumocystis jirovecii, a fungus which is generally found in the lungs of healthy people, without causing disease until the person's immune system becomes weakened.[7]
Risk factors
Pneumocystosis occurs predominantly in people with HIV/AIDS.[8] Other risk factors include chronic lung disease, cancer, autoimmune diseases, organ transplant, or taking corticosteroids.[8]
Diagnosis
Diagnosis of Pneumocystis pneumonia is by identifying the organism from a sample of sputum, fluid from affected lungs or a biopsy.[4][3] A chest X-ray of affected lungs show widespread shadowing in both lungs, with a "bat-wing" pattern and ground glass appearance.[2][7] Giemsa or silver stains can be used to identify the organism, as well as direct immunofluorescence of infected cells.[3] Diagnosis in the eye involves fundoscopy.[12] A biopsy of the retina and choroid layer may be performed.[12] In affected liver, biopsy shows focal areas of necrosis and sinusoidal widening.[10] H&E staining show extracellular frothy pink material.[10] Typical cysts with a solid dark dot can be seen using a Grocott silver stain.[10]
Differential diagnosis
Pneumocystosis may appear similar to pulmonary embolism or adult respiratory distress syndrome.[2] Other infections can present similarly such as tuberculosis, Legionella, and severe flu.[2]
Prevention
There is no vaccine that prevents pneumocystosis.[8] Trimethoprim/sulfamethoxazole (co-trimoxazole) might be prescribed for people at high risk.[8]
Treatment
Treatment is usually with co-trimoxazole.[4][8] Other options include pentamidine, dapsone and atovaquone.[2]
Outcomes
It is fatal in 10-20% of people with HIV/AIDS.[3] Pneumocystosis in people without HIV/AIDS is frequently diagnosed late and the death rate is therefore higher; 30-50%.[3]
Epidemiology
The exact number of people in the world affected is not known.[7] Pneumocystosis affects lungs in around 97% of cases and is often fatal without treatment.[7]
History
The first cases of pneumocystosis affecting lungs were described in premature infants in Europe following the Second World War.[9] It was then known as plasma cellular interstitial pneumonitis of the newborn.[9] Pneumocystis jirovecii (previously called Pneumocystis carinii) is named for Otto Jírovec, who first described it in 1952.[2]
References
- ↑ 1.0 1.1 1.2 1.3 "ICD-11 - ICD-11 for Mortality and Morbidity Statistics". icd.who.int. Retrieved 30 June 2021.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 Russell-Goldman, Eleanor; Milner, Dan A.; Solomon, Isaac (2020). "Pneumocystosis". In Milner, Danny A. (ed.). Diagnostic Pathology: Infectious Diseases. Elsevier. pp. 310–313. ISBN 978-0-323-61138-1.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 "Pneumocystosis | DermNet NZ". dermnetnz.org. Archived from the original on 24 July 2021. Retrieved 24 July 2021.
- ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 "Orphanet: Pneumocystosis". www.orpha.net. Archived from the original on 24 July 2021. Retrieved 24 July 2021.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 Ioachim, Harry L.; Medeiros, L. Jeffrey (2009). "28. Pneumocystosis lymphadenitis". Ioachim's Lymph Node Pathology (4th ed.). Philadelphia: Lippincott Williams & Wilkins. pp. 156–157. ISBN 978-0-7817-7596-0.
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 Calonje, J. Eduardo; Grayson, Wayne (2020). "18. Infectious diseases of the skin". In Calonje, J. Eduardo; Brenn, Thomas; Lazar, Alexander J.; Billings, Steven D. (eds.). McKee's Pathology of the Skin, 2 Volume Set (5th ed.). Elsevier. p. 964. ISBN 978-0-7020-6983-3.
- ↑ 7.00 7.01 7.02 7.03 7.04 7.05 7.06 7.07 7.08 7.09 7.10 7.11 7.12 7.13 7.14 "CDC - DPDx - Pneumocystis". www.cdc.gov. 22 January 2019. Archived from the original on 25 July 2021. Retrieved 25 July 2021.
- ↑ 8.0 8.1 8.2 8.3 8.4 8.5 8.6 "Pneumocystis pneumonia | Fungal Diseases | CDC". www.cdc.gov. 1 December 2020. Archived from the original on 26 July 2021. Retrieved 26 July 2021.
- ↑ 9.0 9.1 9.2 Carmona, Eva M.; Limper, Andrew H. (February 2011). "Update on the diagnosis and treatment of Pneumocystis pneumonia". Therapeutic Advances in Respiratory Disease. 5 (1): 41–59. doi:10.1177/1753465810380102. ISSN 1753-4666. PMC 6886706. PMID 20736243.
- ↑ 10.0 10.1 10.2 10.3 Zaki, Sherif R.; Alves, Venancio A. F.; Hale, Gillian L. (2018). "7. Non-hepatotropic viral, bacterial, and parasitic infections of the liver". In Burt, Alastair D.; Ferrell, Linda D.; Hubscher, Stefan G. (eds.). MacSween's Pathology of the Liver (7th ed.). Philadelphia: Elsevier. p. 477. ISBN 978-0-323-50869-8.
- ↑ O'Malley, Dennis P. (2013). "7.4. Infections: Fungi". Atlas of Spleen Pathology. Springer. pp. 151–155. ISBN 978-1-4614-4671-2.
- ↑ 12.0 12.1 12.2 12.3 12.4 Papaliodis, George N. (2017). "9. Pneumocystis jirovecii". In George N. Papaliodis (ed.). Uveitis: A Practical Guide to the Diagnosis and Treatment of Intraocular Inflammation. Springer. p. 71. ISBN 978-3-319-09125-9.
- ↑ Gigliotti, Frances; Wright, Terry W. (2008). "13. Pneumocystosis". In Hospenthal, Duane R.; Rinaldi, Michael G. (eds.). Diagnosis and Treatment of Human Mycoses. Totowa, New Jersey: Humana Press. ISBN 978-1-59745-325-7.