Allerg

Allerg is a term used in some languages to refer to the condition commonly known in English as an allergy. An allergy is a hypersensitivity of the immune system to substances that are usually harmless to most people, called allergens. Allergen exposure can stimulate an immune response that produces symptoms affecting the nose, eyes, skin, lungs, or digestive tract.

Mechanism: In susceptible individuals, exposure to an allergen leads to the production of allergen-specific IgE antibodies and their attachment to mast cells and basophils. On later exposures, the allergen cross-links the bound IgE, triggering release of histamine and other mediators that cause symptoms such as itching, swelling, runny nose, wheezing, or hives.

Common allergens include pollen, house dust mite, mould, animal dander, certain foods (such as milk, eggs, peanuts, shellfish), insect venoms, and some medicines. Allergies are associated with conditions such as allergic rhinitis, conjunctivitis, asthma, atopic dermatitis, and food allergy. The severity ranges from mild to life-threatening anaphylaxis.

Diagnosis relies on patient history and tests. Skin prick testing and measurements of allergen-specific IgE in blood help identify triggers; oral food challenges may be used for foods when results are uncertain. Diagnosis should be guided by a clinician to avoid unsafe testing.

Management focuses on avoidance of known triggers, symptom-relieving medicines (antihistamines, nasal corticosteroids, inhaled corticosteroids, bronchodilators), and emergency treatment for severe reactions. Epinephrine auto-injectors are essential for anaphylaxis. Allergen immunotherapy (allergy shots or sublingual tablets) may reduce sensitivity for some allergens, and newer biologic therapies target specific immune pathways in severe cases. Ongoing research aims to improve diagnosis, prevention, and treatment.