 2001 DEY B /01

Definition of Anaphylaxis Systemic allergic reaction –Affects body as a whole –Multiple organ systems may be involved Onset generally acute Manifestations vary from mild to fatal –Recurrence up to 8 hours later –Protracted –Hours to days

Signs and Symptoms of Anaphylaxis Skin: Flushing, Itching, swelling, hives Lower respiratory: Bronchospasm, throat or chest tightness, hoarseness, wheezing, shortness of breath, cough Gastrointestinal tract: –Oral itching –Cramps, nausea, vomiting, diarrhea Cardiovascular system: –Increased ht rate then lower heart rrate, hypotension/shock, arrhythmias, ischemia, chest pain

Clinical Manifestations of Anaphylaxis Signs/symptomsIncidence (%) Urticaria and angioedema Upper airway edema* Dyspnea and wheezing Flush* Dizziness, syncope, and hypotension Gastrointestinal symptoms Rhinitis* Headache* Substernal pain* Itch without rash* Seizure* *Symptom or sign not reported in all four series

Anaphylaxis Fatalities Estimated 500–1000 deaths annually 1% risk Risk factors: –Failure to administer epinephrine immediately –Beta blocker, ?ACEI therapy –Asthma –Cardiac disease –Rapid IV allergen

Food-induced Anaphylaxis: Common Triggers Children and adults (usually not outgrown): –Peanuts –Tree nuts –Shellfish –Fish Additional triggers in children (commonly outgrown): –Milk –Egg –Soy –Wheat

Latex-induced Anaphylaxis: Triggers Proteins in natural rubber latex Component of ~40,000 commonly used items –Rubber bands –Elastic (undergarments) –Hospital and dental equipment Latex-dipped products are biggest culprits –Balloons, gloves, bandages, hot water bottles

Venom-induced Anaphylaxis: Common Culprits Hymenoptera –Bees –Wasps –Yellow jackets –Hornets –Fire ants Geographical –Honeybees, yellow jackets most common in East, Midwest, and West regions of US –Wasps, fire ants most common in Southwest and Gulf Coast

Other Causes of Anaphylactic and Anaphylactoid Reactions Drugs –Antibiotics –Chemotherapeutic agents –Aspirin, NSAIDs –Biologicals (vaccines, monoclonal antibodies) Radiocontrast media Exercise Idiopathic

Myth: If you have been stung by a bee or eaten a peanut and have not reacted to it then you do not have Anaphylaxis IgE-mediated (Type I hypersensitivity) Sensitization stage Subsequent anaphylactic response

Myth: Anaphylaxis Is Rare REALITY : Anaphylaxis is underreported Incidence seems to be increasing Up to 41 million Americans at risk (Neugut AI et al, 2001) 63,000 new cases per year (Yocum MW et al, 1999) 5% of adults may have a history of anaphylaxis (various surveys)

Myth: The Cause of Anaphylaxis is Always Obvious REALITY : Idiopathic anaphylaxis is common Triggers may be hidden Patient may not recall details of exposure, clinical course

Myth: Prior Episodes Predict Future Reactions REALITY : No predictable pattern Severity depends on: –Sensitivity of the individual –Dose of the allergen

Myth: Anaphylaxis is Easy to Avoid If You Know What You are Allergic To REALITY : Most cases of anaphylaxis are due to accidental exposures

Treatment of Anaphylaxis Immediate treatment with epinephrine imperative –No contraindications in anaphylaxis –Failure or delay associated with fatalities –IM may produce more rapid, higher peak levels vs SC –Must be available at all times Antihistamine (oral or parenteral; if oral, use liquid or chewable tablet) Call 911; proceed to Emergency Room

Myth: Epinephrine is Dangerous REALITY : Risks of anaphylaxis far outweigh risks of epinephrine administration Minimal cardiovascular effects in children (Simons et al, 1998) Caution when administering epinephrine in elderly patients or those with known cardiac disease

EpiPen ® 2-Pak Call for help (911); transport patient to emergency care facility Stay calm; Keep patient warm

How to use an epipen.

Risk Management for Anaphylaxis Be aware of the problem and keep your “index of suspicion” high. The school nurse will –EDUCATE: the student –Draft an Emergency Plan –In form staff of KNOWN anaphylactic students and STAFF