allergener

Allergener are substances capable of triggering an allergic reaction in individuals who have become sensitized to them. In scientific and medical usage, the term allergen is common, but some languages use a plural form that resembles “Allergener.” Allergens are usually proteins or glycoproteins, though small molecules can become allergenic after binding to larger proteins (haptens). They are encountered in a wide range of environments and foods.

Common sources of allergens include foods such as peanuts, tree nuts, milk, eggs, fish, shellfish, soy, and wheat; environmental allergens such as pollen from trees, grasses, and weeds; dust mites and mold spores; animal dander; insect venoms; certain medications; and some cosmetics or industrial chemicals. The exposure route influences the clinical presentation, with inhaled allergens often causing rhinitis or asthma, and ingested allergens causing oral symptoms or more systemic reactions.

Most allergic reactions are IgE-mediated. After initial sensitization, exposure to an allergen cross-links IgE on the surface of mast cells and basophils, releasing mediators like histamine that produce symptoms ranging from itching, sneezing, and hives to wheezing and, in severe cases, anaphylaxis. Diagnosis combines clinical history with tests such as skin prick testing or serum-specific IgE measurements; in some cases an oral food challenge under medical supervision is used.

Management focuses on avoidance of known allergens, pharmacotherapy to control symptoms, and readiness to treat severe reactions with epinephrine. Allergen immunotherapy (subcutaneous or sublingual) may reduce sensitivity for certain allergens. Public health measures aim to improve labeling and accessibility of emergency treatments for at-risk individuals.