Certain fungal species have the ability to cause diseases in plants and animals. This article provides a list of diseases caused by fungi, that occur in humans.
Fungi is the name given to a large group of eukaryotes, including microscopic organisms such as yeast and molds, as well as complex, multicellular mushrooms. There are thousands of different species that belong to this class, each with distinct characteristics. They are made up of rigid cell walls, and also have a membrane-bound nucleus. These organisms fail to photosensitize as they lack chlorophyll.
Because of their unique characteristics, fungi have been categorized into a separate group, different from plants and animals. Although many species of fungi are beneficial in some way or the other, there are certain species that can cause diseases in humans. General symptoms of such infestations include itching, straining, white patches, and burning on the skin.
Skin Disorders Caused by Fungi
The diseases caused by fungal infestation are together referred to as mycoses. They are classified into different groups, depending on the nature of the tissue that is involved, and mode of entry into the host.
Superficial Mycoses
These are the diseases caused by fungi that grow only on the surface of the skin and hair, i.e., the infection is confined to the outermost layers of skin, nail, and hair. These are the least harmful ones of all fungal infections, as they fail to penetrate the body of the host, and affect only the cells on the surface. Some examples of superficial mycoses and the fungal agents causing them are as follows:
» Black piedra (Piedraia hortae)
» White piedra or tinea blanca (Trichosporon)
» Pityriasis versicolor or tinea versicolor (Malassezia furfur)
» Tinea nigra (Hortaea werneckii)
Subcutaneous Mycoses
These are the infections that affect the dermis and other subcutaneous tissues of the host. These infections generally occur when the pathogen penetrates the dermis during, or after a skin trauma. The lesions then spread locally without penetrating deeper. However, some fungi can cause deep mycoses, particularly in patients with severe underlying abnormalities. Common examples of subcutaneous mycoses are:
» Sporotrichosis (Sporothrix schenckii)
» Chromomycosis (Fonsecaea, Cladosporium, etc.)
» Phaeohyphomycosis (Alternaria, Exophiala jeanselmei)
» Chromoblastomycosis (Fonsecaea pedrosoi, Phialophora verrucosa, Cladosporium carrionii, Fonsecaea compacta)
» Lobomycosis (Lacazia loboi)
» Rhinosporidiosis (Rhinosporidium seeberi)
» Mycetomas (Actinomadura, Noetestudina rosatii, Aspergillus terreus, Curvularia lunata, etc.)
Cutaneous Mycoses
Cutaneous Mycoses are the infections that extend deeper into the layers of the epidermis, as well as invasive hair and nail diseases. The fungi responsible for causing these infections are known as dermatophytes. These infections can cause a lot of pain and discomfort as these organisms penetrate deep into the skin. Some other examples of cutaneous mycoses causing fungi include microsporum, epidermophyton, and trichophyton. Examples of this disease are:
» Ringworm or tinea (dermatophyte)
» Athlete’s foot (Epidermophyton floccosum, T. rubrum, T. mentagrophytes)
– Chronic interdigital athlete’s foot
– Chronic scaly athlete’s foot
– Acute vesicular athlete’s foot
Systemic Mycoses
Systemic mycoses are believed to be the most dangerous of all fungal infections. This is mainly because they invade the internal organs by direct entry through lungs, gastrointestinal tract, or intravenous lines. These can be caused by two groups of fungi – primary pathogenic fungi or the opportunistic fungi. Examples of fungal diseases belonging to the first group include:
» Blastomycosis (Blastomyces dermatitidis)
» Histoplasmosis (Histoplasma capsulatum)
» Paracoccidioidomycosis (Paracoccidioides brasiliensis)
» Coccidiomycosis (Coccidioides immitis or Coccidioides posadasii)
Opportunistic fungi generally affect people with a weak immune system or with some serious metabolic defect. The diseases included in this category are:
» Cryptococcosis (Cryptococcus neoformans and Cryptococcus gattii)
» Candidiasis (Candida)
» Aspergillosis (Aspergillus)
Antifungal treatment options can get rid of these fungal infections. Proper hygiene and food habits help in preventing the onset of any disease, and keep the body healthy.
