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Definition S/SDX/TXHypersensitivityOverly aggressive immune responseType I:Immediate Hypersensitivity-rapid action to antigen (anaphylaxis)-does not occur on 1st exposure to antigen-1st exposure: B cells attach tomast cells to produce IgE-2nd exposure: causes this antibody to react w/antigen immediately -mast cells secrete histamine which act w/in seconds to cause itching, vasodilation, inflammation,& edema-> shock, airway obstruction (d/t laryngeal edema)-mast cells also secrete leukotrienes (act w/in mins to cause smooth mm. constriction leading to bronchospasm)-allergic rhinitis: hayfever, runny nose-hives-asthma-mediates allergy (over response to an exogenous antigen)->doesn’t occur w/ 1st exposureCan lead to->Anaphylaxis shock=severe life-threatening-systemic hypersensitivity rxn-↓BP caused by histamine release-airway obstruction-severe hypoxia-can be caused by: latex, insect stings, nuts/shellfish, or various drugs-generalized itching/tingling, esp.oral cavity-coughing-difficulty breathing-feeling weak-dizziness/fainting-sense of fear or panic-edema around eyes, lips, tongue, hands, feet-hives-collapse w/LOCTX:-require 1st aid response (epipen if ava./ call 911)-Tx in ER: epinephrine, glucocorticoids, antihistamines, O2, stabilize BP-skin tests: to determine cause-desensitization tx giving injections very small amts of antigen to create a blocking antibodyType II:Cytotoxic hypersensitivity =autoimmune rxn-antibody recognizes as self protein as nonself and attaches to cell membrane-antibody kills cells or interferes w/cell fxneg.: transfusion rx, thrombocytopenia, organ transplant rejection, drug rxnsType III:Immune complex =autoimmune rxn-antibody attaches to antigen forming a complex-Eg. Systemic lupus erythematosus, Hep B-produces an inflammatory response locally/circulates & induces inflammation in distant tissues (kidney, joints, heart, microvasculature)-mediates autoimmune disease (immune system mistakes an endogenous substance as foreign)Type IV:Delayed-mediated by T lymph-macrophages attachto antigen &present it to T lymph, activating them to become cytotoxic T cells-when antigen on skin->inflammation (eg. poison ivy, -cause autoimmune disease when killer T cells attack healthy tissue w/ similar antigen
contact dermatitis)-deeper tissue: a cluster of macrophages & T cells forms around antigen, creating granuloma (eg. TB in lung)Systemic lupus erythematosus (SLE)=Type III autoimmune-antibodies to many tissues, which form immune complexes-immune complexes are deposited in connective tissue anywhere in the body Complications:-brain, kidney, joints, blood vessels and & blood cellsRisk factors: -♀20-40 yo-specific cause not established multifactoral-genetics/ estrogen lvls-pregnancy, infection, physical or emotional stress-chronic disease w/ exacerbations & remissions-”butterfly” rash overthe cheeks & bridge of the nose is photosensitive-fatigue, mm aches-swollen, painful joints-photosensitivityTX: certain drugs frequently prednisone, supportive onlyDX: need at least more symptoms involved Nursing interventions: