Immediate Hypersensitivity Reactions

Immediate hypersensitivity reactions, also known as allergic reactions, occur when the immune system overreacts to a harmless substance, like pollen or certain foods. Upon first exposure, the body produces antibodies called IgE, which sensitize the immune system. During subsequent exposures, these antibodies trigger the release of chemicals like histamine, causing symptoms such as itching, swelling, and difficulty breathing. Common examples include hay fever, asthma, and certain food allergies. These reactions can range from mild to severe, sometimes leading to anaphylaxis, a life-threatening response that requires immediate medical attention.