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Allergic Reaction: OverviewAllergyInappropriate, often harmful response to a normally harmless substance AtopyGenetic predisposition to allergic rxns.(Ex: Seasonal allergies Rise in IgE and EsinophilsAntigenForeign invaders. (ex: Pet Dander, peanuts) AntibodyAttacks the antigen Function of IgEBind with… Antigens. This triggers the mast cell “Water balloon of chemical mediators (ex: histamine, leukotrienes)”Will see skin reactions, whelps, Diff breathing, Laryg Edema, hives, rashesTrigger…Release chemical mediatorsDisorders Reference pg1860Antigen B-CellsIgE binds AntigenStimulates release to mast cells binds to B-Cell IgE IgEChemical MediatorsReleased from stimulated mast cellsTrigger sequence of events resulting in symptoms2 typesPrimary Mediators Secondary Mediators Primary Mediators, Pharm Chap 69 HistamineEffects: Edema, Airways, Bronchi, Laryngeal edema, Itching, redness of skin, Mucosa membranes eye/nose (weeping of tissues in general)Maximum amount of intensity is w/in 15min of contact w/ antigenConstriction of bronchiolesDilation of small vessels & constriction of core vesselsTwo types:*H1 receptors- bronchiolar and vascular smooth muscle cells. Activation of H1 receptors causes dilation of small blood vessels. Incr capillary permeability. Bronchoconstriction. Itching/Pain. Mucous secretion.(ex: Benadryl)*H2 receptors- gastric parietal cells. Activation of H2 receptors is secretion of gastric acid. Allergic responses. Histamine release. Severe = Anaphylaxis, (treat: epinephrine).(ex: Zantac, pepcids)Other Primary MediatorsEosinophil Chemotactic factorEosinophils- They incr in number with allergy and parasitic conditions and decr w/ steroid administration. Larger than Neutrophils.Platelet aggregating factorProstaglandins (Will cause the inflammation along w/ fever and pain) Secondary Mediatorsreleased in response to a primary Each causes smooth muscle contraction & increased vascular permeabilityLeukotrienes- responsible for the inflammatory response (responsible for wheals/whelps in skin) Serotonin- Vasoconstrictor Bradykinin- responsible for muscous production Hypersensitivity – 4 typesType I – AnaphylaticType II – CytotoxicType III - Immune ComplexType IV - DelayedType I - AnaphylacticMost severe form of hypersensitivityCharacterized by edema in many tissues & hypotensionBegins within minutes, mediated by IgE antibodies (if no increase in IgE than its not Anaphylactic Reaction) Type 1 is a TRUE ALLERGYSeverity depends on exposure, amount of allergens, sensitivity of target organs, and route of allergen exposure.Requires previous exposureExamples of Type I ReactionsExtrinsic asthma- outside source, ex: pet dander Allergic rhinitisSystemic anaphylaxisInsect sting reactionsVasodilation in extremities, incr capillary permeability, smooth M Contraction, and high levels of eosinophils.Type II or CytotoxicBody attacks self- cytotoxic- related to compliment cascade. Ex (Mgravis, blood transfusion reactions)IgG or IgM antibodyActivation of complement cascadeCell destructionType III or Immune ComplexInvolves IMMUNE COMPLEXES, when antibody binds w/ antigen. They don’t break down the way they should and form slusters leading to…Phagocytosis- tissue damage.Injury due to↑Circulating complexes & Vasoactive amines↑ vascular permeability & tissue injury.Joint & kidneys Type III or Immune ComplexSystemic Lupus Erythematosus (SLE)Rheumatoid ArthritisNephritisBacterial EndocarditisType IV Delayed HypersensitivityNon- Atopic reactions, so no incr in IgE or Eosinophil levels Occurs 24-72 hrs after exposureExamples TB testPoison IvyContact dermatitis (tape, topical medications, cosmetics)S/S = Itching, erythema, raised lesionsNursing Care of HypersensitivitySee Chart 53-7, pg 1876 AssessmentHistoryPhysical assessmentDiagnostic TestingWBC – Normal, because its antigen, not infection Eosinophils (granulated WBC) Normal 1-3%^ 5-15% suggestive allergy^15-40% moderate^50-90% severe- Definite allergic reactionEosinophil count of tissue smearSwab in mouth, oral, throat Diagnostic TestingIgE level ↑ IgE levels indicate allergic disorderUseful in evaluation of:ImmunodeficiencyDrug reactionsAtopic vs. non-atopic dermatitis, asthma, and rhinitis Diagnostic TestingSkin testsPrick/Scratch (easiest test available)IntraDermal (injection of antigen INTO the skin)InterpretationUrticarial wheal, erythema, or pseudopodia “reaching outward of redness”Do not perform while pt has active bronchospasm Diagnostic TestingProvocative testing- direct admin of allergen into target tissue.Only one test per visit.RAST (Radioallergosorbent Test)- The patient's blood is mixed with a possible allergen in a test tube.The Safest cause there is no pt contact. Allergic Disorders2 types AtopicIgE & Genetic predispositionAllergic rhinitisAllergic asthmaAtopic dermatitisNon-atopicNo IgENo organ specificityNo genetic linkAnaphylaxis – Type I HypersensitivityReaction of Antigen + IgE antibodyRelease of histamine, other mediators, & WBCsSmooth muscle spasmBronchospasmMucosal edemaInflammationIncreased capillary permeability- fluids are seepiong into the tissueAnaphylaxis – Type I Hypersensitivity Clinical ManifestationsMildTingling/ warmth, fullness in mouth/throatNasal congestionPerioribital swellingPruritisSneezingModerateSx of mild rx &FlushingWarmthAnxietyItchingAnaphylaxis Clinical ManifestationsSevere (right amount to rt organ Cardiac arrest = PTTP) Abrupt onset of previous symptomsBronchospasmLaryngeal edemaSevere dyspneaCyanosisHypotension… cardiac arrestManagement of Anaphylaxis PreventionAvoidance!!!Epinephrine- epi pen on hand = good. But only use when having reaction! Normal + Pen = Cardiac arrest Screening for allergiesIdentification- allergy band = good Anaphylaxis – Type I HypersensitivityMedical ManagementDepends on severitySupport Resp/Cardiac fxOxygenEpinephrine 1:1000 SQ, then IVAntihistamines, Benadryl, cortisone- to decr inflammation so pt can breathe Iv fluids, volume expanders, vasopressorsPossibly aminophylline or steroidsDesensitization- commonly done for insulin, aka “Controlled anaphylaxis” Anaphylaxis – Type I Hypersensitivity Nursing ManagementAssess pt with allergies for s/sx anaphylaxisIncreasing edemaRespiratory distressNotify physicianO2Prepare emergency medsPatent IVDocument response, VS, labsAllergic Rhinitisa.k.a. Hay fever- most common foorm of respiratory allergy Often with conjunctivitis, sinusitis, & asthmaComplicationsChronic nasal obstruction, polyps, or obstruction in airwaysChronic otitis mediaAnosmia- lack of smell Allergic RhinitisHISTAMINE!!Tissue edema d/t vasodilation and increased capillary permeability.Manifestations of Allergic Rhinitis….Nasal congestionClear, watery dischargeSneezingItchingDry coughHeadacheSinus painAllergic RhinitisNot a severe disease but a serious disease in that it greatly affects quality of life…FatigueLoss of sleepPoor concentrationDry, chapped, sore skin to faceAssessment of Allergic RhinitisHistory- how long had it, anything improves it? Physical AssessmentAllergy testingSerum IgE levelsManagement of Allergic RhinitisRelieve symptomsAvoidance therapyImmunotherapy (allergy shots)- kinda like desensitization Pharmacotherapy Antihistamines- Benadryl (but its sedating), so Zyrtec, ClaritinAdrenergics- stop mucosal weeping, decr edema. Short term use, else poss Rebound Effect.Mast Cell Stabilizers- NasalcromCorticosteroids- Flonase, Nasonex (localized steroids)EducationAllergic Rhinitis: Nursing DiagnosesIneffective breathing patternDeficient knowledge- decongestants will raise BPIneffective individual coping- inability to breath. Feels miserable.Contact Dermatitis A type IV hypersensitivityClinical ManifestationsAcute or Chronic skin inflammationItchingBurningSkin lesionsEdemaWeeping, crusting, drying and peeling of skinRisk of secondary infection d/t scratchingAssessmentFour types:Allergic- pt is suceptible to a certain thingIrritant- 80% of contact dermatiitis casesPhotoxic- chem irritant and a sun exposurePhotoallergic- sun exposure and allergen contact Atopic DermatitisAn allergic contact dermatitis A.K.A. EczemaA type I sensitivity mon in children.Have dry, red, hyperirritable skinExtended contact could lead to severe reactionTreat w/ topical creamDermatitis MedicamentosaSkin rash from internal medication administration (causes BRIGHT RED RASH) Sudden onset. Stop med that causes this, else poss Anaphylaxis. Common type adverse drug rxIntense, vivid colorOther systemic symptoms possibleAlert patient to hypersensitivity (for future prevention)UrticariaHivesPinkish, edematous elevationsItch, local discomfortAngioneurotic edema = Angio edema (the deeper layers of skin. Includes eyelids, lips, feet, tongue)Caution for airway obstructionPrepare for poss TracheostomyCommon side effect of ACE InhibitorsFood AllergiesType 1 HypersensitivityThe Usual Suspects??Seafood, legumes, seeds, nutsEgg whites, Milk, ChocolateClassic allergic and GI symptomsN/V/D, swelling of lips and tongue, Abd pain, WheezingElimination is key to mgmtDrug therapyH1/H2 blockersAntihistaminesAdrenergic- in case of reactionSteroids- reduce inflammationNursing Mgmt – Prevention, Pt & family teaching, recognition of sxLatex AllergiesKeep in mind of all the products that contain… Implicated as cause in many allergic responsesRhinitis-ConjunctivitisContact dermatitis-Urticaria “hives”Asthma-AnaphylaxisLatex Allergy1-3% pop. (10-17% HCW)19% of anesthesia reactionsRoutes of exposureCutaneous, mucosal, Parenteral, aerosol (powder)Latex Allergy Clinical ManifestationsIrritant Contact dermatitis (redness, itching) Non-immunogenic responseErythema, pruritusTreatment: change brands/type Latex Allergy - Type 1Type I – ImmediateRhinitis, conjunctivitis, asthma, anaphylaxisSigns & Symptoms:Localized itching-ErythemaHives-AngioedemaRhinitis-ConjunctivitisAnaphylactic shock-Cardiac arrestLatex Allergy – Type IVType IV – Delayed (Most common type) vesicular skin lesions on back of hands, papules, pruritusMost common typeLatex AllergyDiagnosis:-Skin tests (Prick Test) -RAST test (blood sample) Treatment:-Avoidance-Antihistamines-Emergency suppliesAsk all patients about allergies before beginning treatmentMake sure you post signs and remove latex materials from the room.Teach pt. epinephrine self-injection ................
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