Mycosis | |
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Micrograph showing a mycosis (aspergillosis). The Aspergillus (which is spaghetti-like) is seen in the center and surrounded by inflammatory cells and necrotic debris. H&E stain. | |
Classification and external resources | |
Specialty | infectious disease |
ICD-10 | B35-B49 |
ICD-9-CM | 110-118.99 |
DiseasesDB | 28821 |
MeSH | D009181 |
Mycosis (plural: mycoses) is a fungal infection of animals, including humans. Mycoses are common and a variety of environmental and physiological conditions can contribute to the development of fungal diseases. Inhalation of fungal spores or localized colonization of the skin may initiate persistent infections; therefore, mycoses often start in the lungs or on the skin.
Fungal infections of the skin was the 4th most common disease in 2010 affecting 984 million people.
Individuals being treated with antibiotics are at higher risk of fungal infections.
Individuals with weakened immune systems are also at risk of developing fungal infections. This is the case of people with HIV/AIDS, people under steroid treatments, and people taking chemotherapy. People with diabetes also tend to develop fungal infections. Very young and very old people, also, are groups at risk. Although all are at risk of developing fungal infections, the likelihood is higher in these groups.
Mycoses are classified according to the tissue levels initially colonized.
Superficial mycoses are limited to the outermost layers of the skin and hair.
An example of such a fungal infection is Tinea versicolor, a fungus infection that commonly affects the skin of young people, especially the chest, back, and upper arms and legs. Tinea versicolor is caused by a fungus that lives in the skin of some adults. It does not usually affect the face. This fungus produces spots that are either lighter than the skin or a reddish brown. This fungus exists in two forms, one of them causing visible spots. Factors that can cause the fungus to become more visible include high humidity, as well as immune or hormone abnormalities. However, almost all people with this very common condition are healthy.
Cutaneous mycoses extend deeper into the epidermis, and also include invasive hair and nail diseases. These diseases are restricted to the keratinized layers of the skin, hair, and nails. Unlike the superficial mycoses, host immune responses may be evoked resulting in pathologic changes expressed in the deeper layers of the skin. The organisms that cause these diseases are called dermatophytes. The resulting diseases are often called ringworm (even though there is no worm involved) or tinea. Cutaneous mycoses are caused by Microsporum, Trichophyton, and Epidermophyton fungi, which together comprise 41 species.