What term refers to an exaggerated immune response to a particular substance?

Hypersensitivity is the term used to describe an exaggerated immune response to a specific substance, which can include allergens such as pollen, pet dander, or certain foods. This heightened reaction occurs when the immune system mistakenly identifies a harmless substance as a threat, leading to an overactive immune response that can result in symptoms ranging from mild (like sneezing or skin rashes) to severe (such as anaphylaxis).

While an allergic reaction is a specific manifestation of hypersensitivity, hypersensitivity encompasses a broader range of responses, including various types of allergies classified into types I through IV. Autoimmune disorders, on the other hand, involve the immune system attacking the body's own cells, leading to different types of health issues, and an inflammatory response is a general process that occurs as part of the body’s defense mechanism against injury or infection rather than a specific reaction to a harmless substance. Thus, hypersensitivity accurately captures the essence of an exaggerated immune response.