About 1.2 million known species of fungi are everywhere in our environment. Some fungi live on skin and mucous membranes, others are very tasty or are used for medicinal purposes. Only a few hundred fungi can cause disease. It is not always easy to track down these culprits. Fungi are life forms that belong neither to plants nor to animals. They are unicellular or multicellular and have a very special metabolic behavior. There is a whole range of useful fungi, which serve as edible mushrooms or for the production of food and beverages, as well as medical and pharmaceutical products (for example, antibiotics).
Mycosis-causing fungal species.
Only a few fungi can cause acute or chronic diseases (mycoses) in humans, animals, or plants. The likelihood of this depends partly on the type of fungi and their metabolic capabilities, and partly on the host and its defenses. Some fungi only become pathogens when the immune system is weakened. Potentially pathogenic fungi are divided into three categories:
- Dermatophytes affect the skin and its appendages such as hair and nails.
- Sprout fungi (yeasts) cause infections of the skin and internal organs (often in the case of immune deficiency).
- Molds (filamentous fungi) mainly affect internal organs, may be present in spoiled food and form cancer-causing toxins (aflatoxins).
In addition, many of the higher species of fungi contain toxins that can cause severe to fatal symptoms of poisoning when consumed. In Germany, the tuberous leaf fungus is the most common cause of fatal mushroom poisoning.
Allergy to mushrooms
To reproduce, fungi form so-called spores, which can cause allergies in some people if they are inhaled. There are also structures on the surface of fungi that can trigger allergic reactions. These are very diverse – a fungus can have up to 100 different such substances. Therefore, the detection of the allergy-triggering substances is not easy.
Particularly common causes of allergic symptoms such as rhinitis, conjunctivitis, skin lesions and asthma are certain molds. In environmental medicine, they are often held responsible for the “sick building syndrome“, i.e. complaints triggered by inhaling indoor air contaminated with pollutants.
However, the consumption of mushrooms can also trigger allergies or intolerance reactions in sensitive individuals, especially to the mushroom protein (for example, in the case of the shiitake mushroom). A rare special form of food intolerance to mushrooms is congenital trehalose intolerance. In this case, the trehalose contained in mushrooms cannot be digested, resulting in severe diarrhea after mushroom consumption. In some people, contact also causes skin rashes (for example, with the butter mushroom).
