What is the body's immune response to allergens that can cause immediate inflammation?

The body's immune response to allergens that leads to immediate inflammation is best described as an allergy. When an individual is exposed to certain substances known as allergens, the immune system may recognize these substances as harmful, triggering a rapid inflammatory response. This reaction is characterized by the release of chemicals like histamines, which can cause symptoms such as swelling, redness, itching, and other allergic manifestations.

Allergy encompasses a variety of conditions that arise from this immune response, including hay fever and asthma. Although hay fever is commonly associated with allergic reactions and involves specific symptoms largely related to nasal passages and eyes, and asthma can also be instigated by allergens—leading to respiratory symptoms—the term "allergy" broadly defines the immediate response.

Hypersensitivity refers to an exaggerated immune response and can include a range of reactions, not limited to immediate responses. Therefore, while hypersensitivity captures the essence of an exaggerated response from the immune system to allergens, allergy specifically denotes the immediate inflammatory response that accompanies exposure to allergens.