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9 Cards in this Set
- Front
- Back
define fungal allergen
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fungal produce that elicits a hypersensitivity reaction in a previously exposed host
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List 4 common features of fungal allergens and toxins
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1. fungal cells not necesarily present
2. exoposure via respiratory, GI or skin 3. Large # of people exposed 4. occupational diseases |
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List 4 distinguishing features of fungal allergens and toxins
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1. Fungal allergy is immunologically mediated, mycotoxicosis is not
2. Reactivity to fungal allergens requires prior exposure, suceptibility to fungal toxins does not 3. Fungal allergens have an immediate effect, fungal txoins require a longer time for affect (hours-years) 4. Fungal allergens are proteins or glycoproteins, fungal toxins are low molecular weight secondary metabolites |
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What type of hypersensitivity is fungal allergy
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Type 1
fungal allergen binds to IgE on the surface of sensitized mast cells or basophils which then release histamine resulting in vasodilation and increased capillary permeability |
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What confers the specificity for a particular fungal epitope
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IgE, it can react with the epitope in isolation or on fungal structures
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What compoent of the fungus usually causes allergy
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spore/ conidida
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Discuss the two routes of exposure to fungal allergens
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Both respiratory
1. Upper respiratory tract- rhinitis, characterized by fluid exudation and tissue swelling 2. Lower rspiratory tract- asthma, bronchial smooth muscle constriction and mucus plugging of bronchioles |
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What is the relationship between fungi and intrinsic asthma
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high incidence of skin reativity in intrinsic asthmatics to Trichophyton dermatophtes, astham imporves with antifungal therapy, fungi may be cause of the asthma
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list 5 factors that influence the severity of fungal allergic rxns
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1. frequency of exposure
2. amount exposed to 3. route of exposure 4. geneticallly determine dhost factors influencing susceptibility to particular allergen 5. genetically determined host factors influencing allergic reactivity |