Ülitundlikkused

Ülitundlikkused, known in English as hypersensitivities, refer to an overactive or exaggerated immune response to substances that are normally harmless to most people. These reactions are a type of allergy. The immune system mistakenly identifies a common substance, such as pollen, certain foods, or animal dander, as a threat and triggers a defense mechanism. This defense mechanism can manifest in a variety of symptoms, ranging from mild discomfort to severe, life-threatening conditions like anaphylaxis.

There are several types of hypersensitivity reactions, broadly categorized by the underlying immunological mechanism. Type I hypersensitivity, the most common, involves IgE antibodies and is responsible for immediate allergic reactions like hay fever, asthma, and food allergies. Type II reactions involve antibodies attacking the body's own cells. Type III reactions are caused by immune complexes that deposit in tissues, leading to inflammation. Type IV reactions are delayed hypersensitivity responses mediated by T-cells, commonly seen in contact dermatitis.

Diagnosing hypersensitivities typically involves a combination of patient history, physical examination, and specific tests such as skin prick tests, blood tests to measure allergen-specific antibodies, and sometimes challenge tests under medical supervision. Management strategies focus on avoiding known triggers, using medications to control symptoms (like antihistamines, corticosteroids, or bronchodilators), and in some cases, allergen immunotherapy (allergy shots or sublingual tablets) to desensitize the immune system. The prevalence of hypersensitivities has been increasing globally, contributing to a significant public health burden.