PowerPoint Presentation

Anaphylaxis, Acute Allergic Reactions, and Angioedema

Presented by: M.RezaiEM PhysicianIUMSAnaphylaxis is a medical emergency that requires immediate diagnosis and treatment.

1. Acute onset of an illness (minutes to several hours) with involvement of the skin and/or mucosal tissue (e.g., hives/urticaria, pruritus, flushing, swollen lips, tongue, or uvula) associated with at least one of the following:Respiratory compromise (e.g., dyspnea, wheeze, stridor, etc.)orReduced blood pressureorAssociated symptoms of organ dysfunction (e.g., hypotonia, syncope, incontinence, etc.)2. Two or more of the following that occur rapidly after exposure to a likely allergen for that patient (minutes to several hours):Involvement of the skin and/or mucosal tissueRespiratory compromiseReduced blood pressure or associated symptomsPersistent GI symptoms (e.g., cramps, vomiting)3. Anaphylaxis should be suspected when patients are exposed to a known allergen and develop hypotensionHypersensitivity is an inappropriate immune response to generally harmless antigens. Anaphylaxis represents the most dramatic and severe form of immediate hypersensitivity. Anaphylaxis occurs as part of a clinical continuum. It can begin with relatively minor symptoms and rapidly progress to a life-threatening respiratory and cardiovascular reaction.Epidemiology

Foods, medications, insect stings, and allergen immunotherapy injections are the most common provoking factor.-Lactam antibiotics are estimated to cause 400 to 800 deaths in the U.S. annually, with a systemic allergic reaction occurring in 1 per 10,000 exposures.

Unavoidable Drugs-Lactam antibioticsAcetylsalicylic acidTrimethoprim-sulfamethoxazoleVancomycinNSAIDsVirtually any drugFoods and additivesShellfishSoybeansNuts (peanuts and tree nuts)WheatMilkEggsSalicylatesSeedsSulfitesOthersHymenoptera stingsInsect parts and moldsRadiographic contrast materialVaccinesLatexClinical FeaturesDiffuse urticaria and angioedemaAbdominal pain or cramping, nausea, vomiting, diarrhea, bronchospasm, rhinorrhea, conjunctivitis, dysrhythmias, and/or hypotension.Even mild, localized urticaria can progress to full anaphylaxis, and even to death.Clinical FeaturesThe classic presentation of anaphylaxis begins with pruritus, cutaneous flushing, and urticaria. These symptoms are followed by a sense of fullness in the throat, anxiety, a sensation of chest tightness, shortness of breath, and lightheadedness. As the cascade progresses, decreased level of consciousness, respiratory distress, and circulatory collapse may ensue. A complaint of a "lump in the throat" and hoarseness heralds life-threatening laryngeal edema in a patient with symptoms of anaphylaxis.Clinical FeaturesIn the vast majority of patients, signs and symptoms begin suddenly, often within 60 minutes of exposure. One half of anaphylactic fatalities occur within the first hour. Recurrence: The exact incidence of biphasic phenomenon is unclear, although it has been reported in 3% to 20% of patients.10 (3 to 4 hours after the initial clinical manifestations have cleared). Diagnosis

The diagnosis of anaphylaxis is clinical. Anaphylaxis should be considered when involvement of any two or more body systems is observed, with or without hypotension or airway compromise (e.g., some combination of cutaneous, respiratory, GI, or cardiovascular systems)DiagnosisRespiratory: Rhinitis, pharyngeal edema, laryngeal edema, cough, bronchospasm, dyspneaCardiovascular: Dysrhythmias, collapse, cardiac arrestSkin: Pruritus, urticaria, angioedema, flushingGI: Nausea, emesis, cramps, diarrheaEye: Pruritus, tearing, rednessGU: Urgency, crampsTreatmentEmergency TreatmentTriage: the highest level of urgencyThe single most important step in treatment is the rapid administration of epinephrineMany of the secondary measures may not be necessary.

First-Line TherapyABCs (airway, breathing, circulation) The first-line therapies for anaphylaxis: Epinephrine, IV fluids, and oxygen Vital signs, IV access, oxygen administration, cardiac monitoring, and pulse oximetry measurements should be initiated immediately.Airway and OxygenationThe airway should be examined for signs and symptoms of angioedema (e.g., uvula edema, audible stridor, respiratory distress, hypoxia). If angioedema is producing respiratory distress, intubation should be completed earlyThe patient should be given sufficient oxygen to maintain arterial oxygen saturation >90%.DecontaminationTerminate exposure to the causative agentGastric lavage is not recommended for food-borne allergens. In insect stings, as the stinger continues to inject venom even if it is detached from the insect, remove any stinging remnantsEpinephrineEpinephrine is the drug of choice and the first drug that should be administered in acute anaphylaxis.1 & 2 receptor agent1 activation: reduces mucosal edema and membrane leakage and treats hypotension2 activation: bronchodilation and controls mediator releaseEpinephrineIn patients without signs of cardiovascular compromise or collapse: IM epinephrine 0.3 to 0.5 milligram (0.3 to 0.5 mL of the 1:1000 dilution) IM repeated every 5 to 10 minutes according to response or relapse. EpiPen (0.3 milligram epinephrine for adults) and EpiPen Junior (0.15 milligram epinephrine for children