Pneumocystosis | |
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Other names | Pneumocystis jiroveci pneumonia, [1] Pneumocystis pneumonia, [2] PCP, Pneumocystis carinii pneumonia [3] |
Pneumocystis jirovecii cysts | |
Specialty | Infectious diseases [1] |
Symptoms | |
Complications |
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Types |
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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]
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]
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]
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]
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]
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]
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 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]
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]
There is no vaccine that prevents pneumocystosis. [8] Trimethoprim/sulfamethoxazole (co-trimoxazole) might be prescribed for people at high risk. [8]
Treatment is usually with co-trimoxazole. [4] [8] Other options include pentamidine, dapsone and atovaquone. [2]
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]
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]
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]