What is a Type 1 hypersensitivity?
Type I hypersensitivity (or immediate hypersensitivity) is an allergic reaction provoked by re-exposure to a specific type of antigen referred to as an allergen.
Type I is distinct from type II, type III and type IV hypersensitivities.
Exposure may be by ingestion, inhalation, injection, or direct contact..
Is urticaria a hypersensitivity reaction?
Immunological urticaria is a hypersensitivity reaction mediated by antibodies and/or T-cells that results in mast cell activation.
Is asthma a Type 1 hypersensitivity?
Type I hypersensitivity reactions are immediate allergic reactions (e.g., food and pollen allergies, asthma, anaphylaxis).
What type of hypersensitivity is urticaria?
Type I hypersensitivities include atopic diseases, which are an exaggerated IgE mediated immune responses (i.e., allergic: asthma, rhinitis, conjunctivitis, and dermatitis), and allergic diseases, which are immune responses to foreign allergens (i.e., anaphylaxis, urticaria, angioedema, food, and drug allergies).