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Hypersensitivity describes associate abnormal or pathologic reaction that's caused by associate immunologic response to perennial exposure to associate matter. Hypersensitivity diseases embrace response diseases, during which immune responses area unit directed against self-antigens, AND diseases that result from uncontrolled or excessive responses to foreign antigens. as a result of these reactions tend to occur against antigens that can't be loose (i.e. self-antigens) and since of regeneration systems intrinsic to numerous aspects of the immunologic response, hypersensitivity diseases tend to manifest as chronic issues.
What else can I help you with?
What is the definition of an Anaphylaxis?
Hypersensitivity to a second dose of antigen.
What occurs when the immune system mounts an exaggerated response to a harmless antigen?
hypersensitivity
What individual hypersensitivity to a substance usually antibody-antigen reaction is known as?
It is an allergy
What is an Arthus reaction?
An Arthus reaction is a hypersensitivity reaction involving the in situ formation of antigen/antibody complexes after the intradermal injection of an antigen.
Which term describes an exaggerated life threatening hypersensitivity reaction to a previously encountered antigen?
Anaphylaxis is the term that describes an exaggerated life-threatening hypersensitivity reaction to a previously encountered antigen. It can lead to symptoms such as difficulty breathing, swelling, and a drop in blood pressure, requiring immediate medical attention.
What causes delayed hypersensitivity reactions?
Delayed hypersensitivity reactions, also known as type IV hypersensitivity reactions, are caused by T cells recognizing antigens and triggering an immune response. This can happen hours to days after exposure to the antigen. Common triggers include certain drugs, metals, and infectious agents.
What are delayed hypersensitivity reactions?
Delayed hypersensitivity reactions are immune responses that occur several hours to days after exposure to an antigen. They are mediated by T cells rather than antibodies, leading to the release of inflammatory mediators and recruitment of immune cells to the site of antigen exposure. Examples include contact dermatitis, tuberculin skin tests, and some drug reactions.
What is the difference between hypersensitivity type II and Type III?
Type II hypersensitivity is also known as cytotoxicity hypersensitivity and it may affect variety of organs and tissues. The antigens are endogenous and exogenous chemicals. Type III Hypersensitivity complex type of hypersensitivity and it may affect individual organs like skin, Liver etc.
How is histamine related to allergies?
An allergy is a hypersensitivity to an environmental antigen (allergen). If a person has a hypersensitivity to an antigen they will have a patholigic (disease) response when exposed to that antigen. When the hypersensitive individual is initially exposed to the antigen, they will produce allergen specific antibodies, primarily immunoglobulin E (IgE), that will during subsequent exposures bond with membrane proteins on the mast cell membrane. This bonding allows degranulation (the release of stored chemicals) of the mast cell. Mast cells manufacture and store chemicals, including histamine, that are responsible for the affects of inflamation.
Is a transfusion reaction a subacute hypersensitivity to foreign red blood cells?
A transfusion reaction is typically an acute hypersensitivity reaction to foreign red blood cells, which can occur immediately or within a few hours of the transfusion. Subacute hypersensitivity reactions usually take days to develop after exposure to the antigen, unlike the immediate onset of symptoms seen in transfusion reactions.
The initial exposure to an antigen is called?
Some more context would be helpful. This question sounds like it may be asking about antigen exposure in the field of allergic disease, but it's hard to be sure. Hypersensitivity reactions (the immune system basis for allergies) are based on the principle that allergy follows initial sensitization to an antigen.
What are the categories of hypersensitivity reaction?
Hypersensitivity reactions are classified into four categories: Type I (immediate hypersensitivity), which involves IgE-mediated responses leading to allergic reactions; Type II (antibody-mediated cytotoxicity), where antibodies target specific cells; Type III (immune complex-mediated), characterized by the formation of antibody-antigen complexes that trigger inflammation; and Type IV (delayed-type hypersensitivity), which is mediated by T cells and manifests hours to days after exposure to the allergen. Each type involves distinct immune mechanisms and clinical manifestations.
