Type I hypersensitivity (mechanism of disease) скачать в хорошем качестве

Type I hypersensitivity (mechanism of disease)

This is a flowchart for type I hypersensitivity, or allergic reactions, covering the etiology, pathophysiology, pharmacology, and manifestations. ADDITIONAL TAGS: Risk factors / SDOH Cell / tissue damage Vascular / flow physiology Type 1 hypersensitivity Medicine / pharmacology Infectious / microbial Cytokines / hormones Immunology / inflammation Signs / symptoms Labs / tests / imaging results Diet / nutrition Genetics / hereditary Smooth muscle Pathophysiology pharmacology Etiology Manifestations Prior sensitization (prior contact with the antigen) forms IgE against antigen IgE coats surface of mast cells and basophils Subsequent encounter with antigen IgE-mediated reaction by preformed IgE antibodies: free antigen binds to two adjacent IgE antibodies (crosslinking) Degranulation of mast cells and basophils (rapid) Immediate release of mediators: histamine, prostaglandin, platelet-activating factor, leukotrienes, heparin, tryptase (cytokines and other proinflammatory mediators) Peripheral vasodilation; ↑ vascular permeability ↑ smooth muscle contraction Extravasation of capillary blood Fluid shift into the interstitial space Abdominal cramping Bronchospasm Abdominal pain Cough, wheeze Hypotension Pruritus Erythema → rash Edema (leg, pulm) Hypovolemia Rapid reaction (within minutes) Eosinophil and neutrophil chemotaxis Inflammation and tissue damage Rhinorrhea, sneezing Coughing, wheezing Erythema Late-phase reaction (hours later, lasting 2-3 days) Cytokines in the subcutan. tissue Cytokines in the superficial dermis Angioedema Hives → wheals (well-circumscribed, raised, pruritic, and erythematous plaques with a round, oval, or serpiginous shape) Allergic asthma Cytokines in eye Allergic conjunctivitis Cross-reacting antigens: Pollen ⇔ foods (apple, hazelnut, carrot, kiwi, apricots, peaches) Mites ⇔ crustaceans Latex ⇔ exotic fruits (banana, avocado, kiwi) Bird dander ⇔ egg yolk Cat dander ⇔ pork History of asthma, atopic dermatitis, allergic rhinitis, allergic conjunctivitis, food allergies Epinephrine Antihistamines (diphenhydramine, cetirizine)