hypersensitivity

A state of incr. or excessive response to the presence of an antigen (foregin protein or allergen) to which the client has been previously exposed

• -most common allergic rxn
• -occurs w/in minutes of exposure to antigen
• -reaction of IgE antibody on mast cells w/ antigen which results in release of meiators, esp. histamine
• -e.g.: asthma, anaphylaxis

• -characterized by antibody formation against an antigen
• -e.g. autoimmune hemolytic anemia and Goodpasture's disease

• -characterized by antibody-antigen complexes that cause vessel or tissue injury
• -e.g. RA, autoimmune diseases, SLE, vasculitis

• -characterized by sensitized T-lymphocytes releasing cytokines that cause cytotoxicity or delayed-typer hypersensitivity
• -e.g.: PPD, transplant rejection, Graves

• 1)pt. exposed to allergen
• 2)person makes antigen-specific IgE which binde to basophils and mast cell. Once antigen-specifif IgE is formed pt. is sensitized
• 3)pt. has 2nd exposure to allergen
• 4) Primary phase: antigen binds to 2 IgE molecules on surgace of basophil or mast cell, distorting cell membrane. Histamine is released causing nasal congestion, prutitis, erythema, incr. cap. permeablilty...
• Secondary phase: other vasoactive amines draw WBC to the area and stimulate more inflammatory rxn thru biochemicals leukotriene and prostaglandins

• -an extreme Type 1 hypersensitivity rxn, a uncommon but life-threatening emergency!
• -affects multiple organs w/in seconds of exposure to allergen
• -pt. c/o uneasiness, apprehension, weakness, impending doowm, agitation
• -generalized pruritis and urticaria (hives), angioedema of eyes, lips and tongue
• -histamine and other biochemicals cause bronchoconstriction, mucosal edema, and excessibe mucous producting causeing rhinorrhea, dyspnea, resp. distress w/ audible wheezing
• -laryngeal edema causes stridor, hypoxemia, hypercapnia
• -hypotension w/ weak pulse d/t vasodilation, incr. cap. permeability and leakage of intravascular fluids
• -resp. failure, shock and cardiac dysrhythmia....death!

No, but you inherit the ability to make IgE (not the actual allergy itself)

• -PREVENTION! avoid offending allergen...
• -basic first-aid kit w/ epipen if kjnown hymenoptera allergy (bees, wasps, hornets)
• -give 2-6L NC or 40% mask
• -antihistamines: PO, IM, IV...diphenhydramine (benadryl) blocks H1 receptors in bronchioles and GI tract and blood vessels
• -if progresses...CPR, intubation PRN, epi SQ or IV (alpha vasoconstrictor, incr. cardiac contraction and dilates bronchioles
• -IV corticosteroid

• Normal: red, painful, itchy
• Large local: more painful and swollen in surrounding areas, may last for days
• Severe allergic: ANAPHYLAXIS! danger!

Scrape it out of the skin, a credit card works good. Don't squeeze it or use tweezers bc stinger has venom sac and you could end up injecting more venom into the wound

• -support ABC's!
• -notify companion in case assistance becomes necessary
• -monitor for dyspnea, bronchospasm, tachycardia, hypotension. If signs of shock call 911 and place pt. supine w/ legs elevated

• -apply ice for pain
• -for redness/swelling try: baking soda mixture, meat tenderizer, oral benadryl (pill or liquid), topical OTC steroids (cortaid, lanacort)
• -clean wound and apply antiseptic/antibiotic to prevent infection
• -teach pt. to wear medic alert bracelet and have epipen avail.

• -IV AB and contrast media, esp PCN family and cephalosporins
• -laytex, blood...
• -tx: stop infusion! ABC's
• -VS and pulse ox
• -notify MD
• -Get new bag and tubing of NS (or whatever new sln to be hung) to tx hypotension
• -epinephrine 0.5 mL 1:1,000 sln SQ or 1ml of 1:10,000 IV
• -possible IV antihistamine or corticosteroid
• -VS, pulse ox, cardiac monitoring q 5 min until hemodynamically stable