Diagnosed Allergic Conditions in Adults: United States, 2021.

An allergy occurs when an individual's immune system misclassifies typically harmless substances as harmful and has a specific and reproducible immune response (1,2). The severity of allergy symptoms can range from itchy, watery eyes and hives to life-threatening anaphylaxis, and the presence of allergies can negatively impact an individual's quality of life (3-6). This report uses 2021 National Health Interview Survey (NHIS) data to describe the prevalence of seasonal allergies, eczema, and food allergies in adults in the United States.