Aspergillosis : Definition, Causes, Symptoms, Diagnosis and Treatment
Aspergillosis is a disease caused by a fungus of the genus Aspergillusis which consists of many species.
The predominant species is Aspergillus fumigatus , involved in 80% to 90% of human aspergillosis. In humans, these fungi are the source of four major types of diseases:
- Allergic disease: the allergic bronchopulmonary aspergillosis;
- Systemic infections: invasive aspergillosis;
- A local infection: the aspergilloma;
- An achievement of the sinuses: sinusitis or aspergillosesinusienne aspergillosis.
Much more rarely, and mostly in people with immune deficient (immunocompromised), aspergillosis is manifested by other attacks: Bone, brain, skin …
Aspergillosis (img thank to : ufandshands.org
The Aspergillus molds are present in the external environment (air, soil, plants, water …), but also inside the premises such as houses or hospitals where they can find the conditions for their development (humidity, insulation and poor ventilation).They produce millions of spores which are carried in the air and inhaled into the lungs. In the majority of the population, natural defenses are sufficient to eliminate them. In some cases, these are exceeded and the disease develops. The greater the amount of spores, the greater the risk of disease is high. This risk is also increased in immunocompromised individuals.
Other modes of transmission are possible exceptional: the deposition of spores in wounds or skin burns cause a local infection, and their penetration into the eye during a trauma, infection external canal of the ear lesions favored by existing contamination from the gastrointestinal tract.
Thanks to their very small size, Aspergillus spores enter through the respiratory tract to the pulmonary alveoli. We then distinguish two cases:
- The fungus in the body causes hypersensitivity reactions via the production of toxins (mycotoxins) to cause allergic reactions;
- The fungus causes a true infection: the case of aspergilloma and invasive aspergillosis.
The allergic bronchopulmonary aspergillosis develops readily in subjects with asthma or cystic fibrosis. Reactions against Aspergillus are responsible for inflammation and bronchial obstruction. In aspergilloma, the Aspergillus develops within a lung cavity that persists at the waning of another disease, especially tuberculosis or sarcoidosis. They form a ball that looks like a tumor. Invasive aspergillosis is the dissemination of the fungus through the bloodstream, primarily in the lungs and other organs.
The symptoms of aspergillosis differ depending on the type of reach.
- The allergic bronchopulmonary aspergillosis is manifested by signs that resemble those observed in asthma: shortness of breath (dyspnea), wheezing and cough occurring in spurts, sometimes with brown sputum. Some patients develop respiratory failure can be severe.
Another allergic aspergillosis has been described: extrinsic allergic alveolitis that occurs after inhaling a large amount of spores, essentially in a professional, especially among farmers.
- Invasive aspergillosis is the most severe form. It affects people who are predominantly underwent an organ transplant or are treated for a malignant disease of the blood (hematologic). It occurs most often nonspecific pulmonary symptoms: chest pain, coughing up blood (hemoptysis) with a high fever. She is also responsible for a breach of the general condition and results in some patients, various symptoms depending on the spread of the fungus.
- The aspergilloma is a local infection which initially evolves silently. It is often discovered during hemoptysis that appear when the disease is already advanced. These are frequently associated with chronic cough, fever, weight loss and fatigue.
- Aspergillus sinusitis causes the same symptoms as those encountered in any sinus headache, sinus pain, nasal obstruction. It is a chronic sinusitis most often unilateral.
The Aspergillus can infect organs other than the airways:
- Ears: otomycosis;
- The eye: ocular aspergillosis occurs as a violation of the cornea (keratitis) or the choroid and retina (chrorioretinite);
- Skin: cutaneous aspergillosis;
- Nails: onyxis or Aspergillus onychomycosis in Aspergillus ;
- The bones, brain, liver, kidneys, heart can be the seat of a localized aspergillosis.
The diagnosis of aspergillosis is based on several types of tests whose indications are guided by the form of the disease:
- X-rays and CT;
- Examination of bronchial endoscopy (bronchoscopy);
- Research in the blood of specific antigens, antibodies (serology);
- Allergic skin tests against Aspergillus fumigatus ;
- The detection of Aspergillus in bronchial secretions, sinus specimens, sputum, biopsies, the cerebrospinal fluid …
- Allergic bronchopulmonary aspergillosis is treated with corticosteroids and drugs used against fungi: antifungals.
- The aspergilloma is usually associated with surgical treatment, in some cases, antifungal therapy.
- Invasive aspergillosis requires antifungal therapy.
- Aspergillus sinusitis is treated, as appropriate, by a simple sinus drainage or surgery and antifungals.
What specialty concerned?
Exercised most often in the hospital, and that specialty studies supports the diseases caused by microbes: bacteria (tuberculosis, skin infections), virus (AIDS, hepatitis), mushrooms (fungi), parasites (malaria). Most of these diseases exist in France, but they are still present in the tropics.
Today, with increased travel and because of climate change, tropical diseases are increasingly common in hospitals.
, genus Aspergillusis