allèrgens

Allergens, or allergènes, are substances capable of triggering an allergic reaction in certain individuals. In susceptible people, exposure to an allergen prompts an immune response mediated by allergen-specific IgE antibodies, leading to the release of inflammatory mediators from mast cells and basophils.

Common allergens include airborne pollens, mold spores, and animal dander; foods such as milk, eggs, peanuts, tree nuts, soy, wheat, fish, and shellfish; certain medicines; insect venoms; latex; and contact allergens like nickel or fragrances.

Symptoms vary and may affect skin, eyes, airways, and digestive tract, ranging from itching, hives, and sneezing to wheezing and anaphylaxis. Severe reactions require immediate treatment with epinephrine and medical attention.

Diagnosis relies on history, skin prick testing or specific IgE blood tests, and, in some cases, supervised oral food challenges. Management emphasizes avoidance, labeling, and preparedness, including access to antihistamines, corticosteroids, inhaled therapies, and, for high-risk individuals, epinephrine auto-injectors; immunotherapy is an option for some allergens.

Public health measures include allergen labeling and safety standards. In many regions, major food allergens are listed on labels. Understanding cross-reactivity and individual risk guides prevention and treatment.