Final answer:
Autoimmune diseases are caused by the immune system mistakenly attacking the body's own tissues, while allergies, like an allergy to pollen, are classified as immediate hypersensitivity, where the body reacts to a harmless antigen.
Step-by-step explanation:
Disorders caused by injurious or pathological immune responses are called autoimmune diseases. An allergy to pollen, specifically, is classified as immediate hypersensitivity. This type of reaction occurs when the immune system is hypersensitive to a harmless antigen, in this case, pollen, which typically causes little or no response in most individuals. Allergic reactions can be due to a variety of allergens such as pollen, dust mites, and specific foods. Allergies are an inflammatory response to what the body perceives as foreign, but they do not involve the immune system attacking its own proteins, unlike autoimmune diseases.