Pathogenesis (development of disease)
Molds are mainly inhalant allergens (aerogenic (airborne) allergens) that are widely distributed indoors as well as outdoors.
Mold allergy describes an allergy to mold spores and/or other mold constituents.
The most common allergens are Aspergillus and Penicillium (mostly indoor) and Alternaria (most important representative: Alternaria alternata) and Cladosporium (mostly outdoor air).Molds that are most likely to indicate moisture damage indoors are:
- Acremonium spp.
- Aspergillus penicillioides
- Aspergillus restrictus
- Aspergillus versicolor
- Chaetomium spp.
- Phialophora spp.
- Scopulariopsis brevicaulis
- Scopulariopsis fusca
- Stachybotrys chartarum
- Tritirachium (Engyodontium) album
- Trichoderma spp.
A prerequisite for the growth of mold is sufficient moisture in the material or surfaces. This is favored by high humidity, lack of ventilation and cold surfaces and is the result of condensation due to a dew point undershoot.
Molds can cause both type I and type III allergies.Immediate-type allergy (synonyms: Type I allergy, Type I allergy, Type I immune reaction, immediate allergic reaction) is characterized by a rapid response of the immune system (within seconds or minutes) upon second contact with the allergen (latex proteins).The initial contact, which is usually asymptomatic, is called sensitization. In this case, T and B lymphocytes recognize the antigen in question independently of each other.The second reaction is IgE-mediated. Here, the allergen binds to the IgE present on the mast cells and histamine is released. Furthermore, inflammatory mediators such as prostaglandins and leukotrienes are released.
Type III allergy (synonyms: type III allergy, immune complex type allergy, type III hypersensitivity reaction) is characterized by the formation of immune complexes (allergen + antibody), which may be cellular or float freely in the blood. The immune complexes form within hours after allergen contact.The allergic immune complex reaction is mediated by antibodies (IgG, IgA, IgM). The immune complexes activate the complement system and trigger phagocytosis (“eating the cell”) of the complexes by leukocytes (white blood cells), which in turn releases cytotoxic (cell-damaging) enzymes (“metabolic accelerators”).
Etiology (causes)
Biographic causes
- Occupations – occupations with activities involving handling organic mold-containing materials, such as being a gardener, miller, baker, vintner, brewer, farmer, or worker in recycling, composting, or sewage treatment plants.
Behavioral causes
- Unhealthy indoor environment – mold growth in the home, water damage, rising damp, condensation, etc.
Disease predisposing causes.
Other causes
- Atopy – hypersensitivity of the (mucous) skin to environmental substances.
