Allergic rhinitis Flashcards
Inappropriate or exaggerated response to an antigen or an allergen
Hypersensitivity
antigens that enters the body, trapped in antigen presenting cells ( Macrophages/ Dendritic cells)
Exogenous
Body’s own cell or sub fragments
Endogenous
normal proteins or complexes that is recognized by the immune system of someone with an autoimmune condition
Auto antigen
Exogenous examples
Microorganisms, allergens
Endogenous examples
Blood group antigen, histocompatibility leucocyte antigen
Auto antigen examples
Thyroglobulin
IgE mediated release of histamine, mast cells and basophils
Type 1: Allergic reaction ( immediate hypersensitivity)
Allergic reaction examples
Bee sting, latex allergy, medications (penicillin), urticaria, anaphylaxis, atopy
refers to the genetic tendency to develop allergic diseases such as allergic rhinitis, asthma, and atopic dermatitis (eczema)
Atopy
Commonly associated with heightened response of IgE
Atopy
Involves IgG and IgM bound cell surface antigens
Type 2: Cytotoxic reaction
Type 2: Cytotoxic reaction duration
Hours to days
Type 1: Allergic reaction duration
Reaction within 1 hour
Involves circulating IgG and IgM immune complex that deposits in post-capillary venules
Type 3: Immune complex reaction
Type 3: Immune complex reaction duration
1-3 weeks
Type 3: Immune complex reaction examples
SLE, Serum sickness
Cell mediated immunity
Type 4: Delayed hypersensitivity
Mediated by T-cells rather than antibodies
Type 4: Delayed hypersensitivity
Type 4: Delayed hypersensitivity duration
Days- weeks
Type 4: Delayed hypersensitivity examples
nickel allergy, SJS, poison ivy
involves inflammation of nasal mucous membranes in sensitized individuals when inhaled allergenic particles contact mucous membranes and elicit a response mediated by immunoglobulin E (IgE).
Allergic rhinitis
Mediators of immediate hypersensitivity
Histamine, leukotrienes, prostaglandin, tryptase, and kinins