Monday 8 June 2015

What is aspergillosis? |


Causes and Symptoms

Members of the fungal
genus
Aspergillus are widely distributed in soil and decaying plant material. Inhalation of fungal spores can cause allergic reactions in people with asthma, a condition called allergic bronchopulmonary
aspergillosis. In someone with a preexisting lung cavity caused by tuberculosis
or cystic fibrosis, the fungus can grow within this cavity and form a fungus ball (aspergilloma) that moves within the cavity but does not invade the cavity wall. However, if the immune system works poorly because of chronic steroid treatment, alcoholism, or underlying lung disease, then the fungus ball can invade the surrounding lung tissue, a condition called chronic necrotizing pulmonary aspergillosis. If the immune system is profoundly weakened because of a recent organ transplant, advanced Acquired immunodeficiency syndrome (AIDS), or genetic diseases that cripple the immune system, then initial colonization of the lung with Aspergillus leads to dissemination of the organism through the bloodstream to other organs (invasive aspergillosis). This results in a rapidly progressing and often fatal systemic
infection.




Allergic reactions to Aspergillus or fungus balls usually cause fever, coughing that sometimes produces blood or brownish mucus, wheezing, recurrent episodes of lung obstruction, and sometimes sinus infections. The symptoms of invasive aspergillosis may additionally include chills, headaches, shortness of breath, chest pain, coughs that produce blood-filled material, bone pain, blood in the urine, decreased urine output, and symptoms involving specific organs, such as meningitis (brain), blindness or visual impairment (eye), sinusitis, and endocarditis (heart).




Treatment and Therapy

For allergies to Aspergillus, oral corticosteroids
are used, since inhaled steroids
are typically ineffective. Addition of the antifungal drug itraconazole to steroids might be necessary for patients whose allergies fail to resolve. Fungus balls are usually not treated unless they cause symptoms. Surgical resection of the affected part of the lung can cure fungus balls permanently, but only in people who have enough lung capacity to survive such a procedure. Invasive aspergillosis requires immediate therapy, and voriconazole is the usual first treatment choice. Amphotericin B is also a viable option, but its toxicity makes voriconazole the better choice. Caspofungin or posaconazole are also effective in those patients who do not tolerate or respond to other drugs. Fungus balls that invade the lung require prolonged treatment with voriconazole, itraconazole, or amphotericin B formulations to cure the patient completely, but surgical
resection of the affected portion of the lung might be necessary.




Bibliography:


Barnes, Penelope D., and Kieren A. Marr. “Aspergillosis: Spectrum of Disease, Diagnosis, and Treatment.” Infectious Disease Clinics of North America 20 (2006): 545-561.



MedlinePlus. "Aspergillosis." MedlinePlus, Apr. 22, 2013.



Patterson, Thomas F. “Aspergillus Species.” In Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases, edited by Gerald L. Mandell, John F. Bennett, and Raphael Dolin. 7th ed. New York: Churchill Livingstone/Elsevier, 2010.



Polsdorfer, Ricker, MD. "Aspergillosis." Health Library, Dec. 30, 2011.



Richardson, Malcolm D., and Elizabeth M. Johnson. Pocket Guide to Fungal Infection. 2d ed. Malden, Mass: Blackwell, 2006.

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