Final answer:
Malassezia hypersensitivity is an allergic reaction to a specific type of yeast, classified under Type I immediate hypersensitivity, which involves a rapid immune response upon exposure to an allergen.
Step-by-step explanation:
Malassezia hypersensitivity in allergy is C) an allergic reaction to a yeast. This yeast, part of the normal skin flora, can sometimes cause an immune response in sensitized individuals. Allergic reactions to pollen, similar to those caused by yeast, are classified as d. immediate hypersensitivity.
These reactions are part of the Type I Hypersensitivities where a sensitized individual is exposed to an allergen, leading to a rapid and almost immediate immune response marked by the release of inflammatory molecules from mast cells.
Another form of allergic reaction is eczema, which is often associated with a hypersensitivity to environmental allergens, such as dust mites, although the direct causative link is not conclusively proven. In contrast, Type II hypersensitivities are characterized by antibody-mediated cytotoxic responses, different from the IgE-mediated reactions of Type I hypersensitivities.