Anaphylaxis

1. Anaphylaxis

2. Objectives • Know the etiologic agents that commonly cause anaphylaxis • Know the signs and symptoms of anaphylaxis • Know how to use an epipen and be able to demonstrate it! • Plan effective treatment of anaphylaxis

3. Anaphylaxis • Is a severe allergic reaction • Involves more than one bodily system, for example the skin and respiratory tract or gastrointestinal tract • Can be life-threatening • Epinephrine, or adrenaline, is the medication of choice for handling an anaphylactic reaction

4. Pathogenesis of Anaphylaxis • IgE-mediated (Type I hypersensitivity) • Sensitization stage • Subsequent anaphylactic response

5. Sensitization Stage  Antigen (allergen) exposure Antigen  Plasma cells produce IgE antibodies against the allergen Plasma cell IgE Mast cell with fixed IgE antibodies  IgE antibodies attach to mast cells and basophils Granules containing histamine

6. • • • • • • • • • • • • • • • • • Anaphylactic Reaction  More of same allergen invades body Antigen • • • • • • • • • • • • • •  Allergen combines with IgE attached to mast cells and basophils, which triggers degranulation and release of histamine and other chemical mediators • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Mast cell granules release contents after antigen binds with IgE antibodies • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • . • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Histamine and other mediators • • • • • • • • •

7. Common Causes of IgE-mediated Anaphylaxis • Foods • Insect venoms • Latex • Medications • Immunotherapy • Insect venom • Inhalant allergens

8. Anaphylactoid Reactions • Non–IgE-mediated • Complement-mediated • Anaphylatoxins, eg, blood products • Direct stimulation • eg, radiocontrast media • Mechanism unknown • Exercise • NSAIDs

9. True or False: The Cause of Anaphylaxis is Usually Obvious FALSE: • Idiopathic anaphylaxis is common • Triggers may be hidden • Foods • Latex • Patient may not recall details of exposure, clinical course

10. Food-Allergy Induced Anaphylaxis • Accounts for 30,000 emergency room visits each year • Causes between 150 to 200 deaths each year; many are children • More people die of food allergy reactions than insect sting and medication allergy

11. Symptoms of a Severe Allergic Reaction Can Include Respiratory tract: • Itchy, watery eyes, running or stuffy nose, sneezing, cough, tingling of the mouth, itching or swelling of the mouth or throat, difficulty breathing, shortness of breath, wheezing, asthma, GI tract: • abdominal cramps, nausea, vomiting, diarrhea Skin: • hives, eczema, itchy red rash, swelling

12. Symptoms of a Severe Allergic Reaction Can Include (2) Cardiovascular • Drop in blood pressure, loss of consciousness/fainting, shock, death

13. Explanation of Table • The following table summarizes the presenting signs and symptoms documented in 4 studies involving 743 patients with anaphylaxis. • Those items starred were not reported in all 4 studies • Other symptoms of rhinitis, headache, substernal pain, and pruritus without rash were less commonly observed.

14. Clinical Manifestations of Anaphylaxis Signs/symptomsIncidence (%) Urticaria and angioedema 88 Upper airway edema* 56 Dyspnea and wheezing 47 Flush* 46 Dizziness, syncope, and hypotension 33 Gastrointestinal symptoms 30 Rhinitis* 16 Headache* 15 Substernal pain* 6 Itch without rash* 4.5 Seizure* 1.5

15. True or False: Anaphylaxis Presents with Cutaneous Manifestations >90% of Cases FALSE: • Approximately 10%-20% of anaphylaxis cases will not present with hives or other cutaneous manifestations • 80% of food-induced, fatal anaphylaxis cases were not associated with cutaneous signs or symptoms

16. Clinical Course of Anaphylaxis • Uniphasic • Biphasic • Recurrence up to 8 hours later • Protracted • Hours to days

17. Anaphylaxis • Patients with peanut or tree nut allergy and asthma appear to be at increased risk for anaphylaxis • Epinephrine (adrenaline), the medicine of choice for treating an anaphylactic reaction is available by prescription as an auto-injector • EpiPen® or EpiPen Jr.®

18. EpiPen® 2-Pak * EpiPen® 2-Pakwas launched in April 2001

19. Dosing of Epipen and Epipen Jr • Epipen = 0.3 mg of epinephrine • > 66 lbs • Epipen Jr = 0.15 mg of epinephrine • <66 lbs

20. Anaphylaxis Management • Accidents are never planned • Quick treatment can be life-saving • Create a plan for managing a reaction before the patient needs it! • Up to 20% of students who will have an anaphylactic reaction have their first one in school

21. Anaphylaxis Management An emergency plan of action should include: • What symptoms to look for • What medications to use • Medication dosage instructions • Where will medications be kept • What others should do • Allergy emergency practice drills • MedicAlert bracelet

23. How to Use EpiPen® How to Hold • Form a fist around the center of the unit • Pull off gray activation cap How to Use • Hold black tip near outer thigh (always apply to thigh) Count to 10 • Swing and jab into outer thigh. Hold in place and count to 10

24. Know how to use the device!! • In a study involving use of an Epi-pen trainer device, both junior and senior physicians were not proficient. • In nearly 40% of efforts, epinephrine would NOT have been adequately administered to the patient. • Only 2/100 doctors demonstrated all 6 steps of the process correctly. Mehr S, Robinson T, Tang M. Doctor – How do I use my epipen? Pediatr Allergy Immunol 2007; 18 (August): 448-452

25. Fatal Food-induced Anaphylaxis (Bock SA, et al. JACI 2001;107:191–193) • 32 cases of fatal anaphylaxis • Adolescents or young adults • Peanuts, tree nuts caused >90% of Rxn • 20 of 21 with complete history had asthma • Most did not have epinephrine available

26. Storage of Epipen • Keep at room temperature – no glove compartments • Do not expose to direct sunlight • Always have multiple units available • In case you cannot reach a hospital within a few minutes and need 2nd dose

27. Venom-induced Anaphylaxis: Incidence • 0.5%–5% (13 million) Americans are sensitive to one or more insect venoms • Local reactions do not predict a severe reaction • Incidence is underestimated • Incidence increasing due to fire ants and Africanized bees • Incidence rising due to more outdoor activities • At least 40–100 deaths per year

28. 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

29. Venom-induced Reactions: Common Symptoms • Normal:Local pain, erythema, mild swelling • Large local: Extended swelling, erythema • Anaphylaxis: Usual onset within 15–20 minutes • Cutaneous: urticaria, flushing, angioedema • Respiratory: dyspnea, stridor • Cardiovascular: hypotension, dizziness, loss of consciousness • 30%–60% of patients will experience a systemic reaction with subsequent stings

30. What you should know about Latex Allergy • Latex allergy is an emerging health issue • Affects 5 to 10% of healthcare workers • Affects 1 to 6% of general population • High risk groups • Rubber industry workers • Health care workers • Children with spina bifida and others with multiple surgeries

31. 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

32. Latex and Food Allergy Connection Protein in some foods cross react with latex proteins: • Bananas • Chestnut • Passion fruit • Avocado • Kiwi • Celery • Melon

33. Latex-containing Products that Commonly Cause Reactions • Gloves • Balloons • Condoms

34. Latex-containing Products* that Rarely Cause Reactions • Rubber bands • Erasers • Rubber parts for toys • Products made from crepe rubber (soles of shoes) • Latex clothing • Elastic on clothing • Feeding nipples and pacifiers * Latex paint does not contain latex

35. Diagnosing Anaphylaxis • Skin tests/RAST • Foods • Insect venoms • Drugs • Challenge tests • Foods • NSAIDs • Exercise

36. 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

37. Treatment of Anaphylaxis • Additional measures may include • Corticosteroids • Supplemental O2; airway maintenance • IV fluids, vasopressor therapy • Repeat epinephrine if Sx persist or increase after 10-15 minutes • Repeat antihistamine ± H2 blocker if Sx persist • Observe for a minimum 4 hours • Arrange follow-up care, provide EpiPen® Rx and education

38. Risk Management for Anaphylaxis • SCREEN • Atopy • 10% of children with asthma have food allergy • 30%–40% of children with atopic dermatitis have food allergy • Previous reactions • 75% will have more than one • 57% will have three or more

39. Screening Patients at Risk Did you ever have a severe allergic reaction: • To any food? • To any medicine? • To an insect sting? • To latex? • That caused breathing trouble? Severe hives and swelling? Severe vomiting or diarrhea? Dizziness? • That required you to go to the hospital?

40. Anaphylaxis Screen, educate, and protect + Immediate treatment = Saved lives