Allergies and Anaphylaxis: Causes, Symptoms, and Management

1. Chapter 14 Allergies and Anaphylaxis

2. Objectives 14.1 Define the following terms: allergy allergic reaction anaphylaxis antigen hypersensitivity 14.2 List four routes by which an antigen may enter the body. 14.3 List four potential allergy sources. continued

3. Objectives 14.4 List the signs and symptoms of an anaphylactic reaction. 14.5 Describe and demonstrate the steps for properly using portable epinephrine auto-injectors.

4. Topics • Anatomy and Physiology • Common Causes of Allergies and Anaphylaxis • Assessment • Management • Chapter Summary

5. Case Presentation • A hiker complains of shortness of breath and that her tongue feels “fat” after photographing some wild flowers 15 minutes ago. • She denies any medical problems but states, “I am deathly allergic to bees!” • Although she does not believe she was stung, you notice a few honeybees buzzing around a stump a few feet away.

6. Anatomy and Physiology • Immune system: Protects the body from foreign substances, or antigens, by developing antibodies. • Primary components: Mast cells, white blood cells, hormones, bone marrow, thymus, and spleen. continued

7. Anatomy and Physiology • Antibody-antigen reaction: Mast cells attack the offending antigen, which causes a reaction that destroys it without harming normal cells. • Allergic reaction: An acquired, abnormal over-reaction by the immune system to an otherwise harmless substance that results in a hypersensitivity.

8. Common Causes of Allergies and Anaphylaxis • Foods , especially peanuts and shellfish • Environmental irritants • Pollen • Molds continued

9. Common Causes of Allergies and Anaphylaxis • Animal dander • Medications • Chemicals • Other such as blood transfusion

10. Common Causes of Allergies and Anaphylaxis

11. Mild Allergic Reaction • Typically results in local dermatologic changes, especially on the face and/or neck. Nasal mucosa and/or congestion are also common. • Symptoms may take minutes, hours, or even days to develop. • Effects usually disappear over time or with treatment. continued

12. Mild Allergic Reaction Signs and Symptoms • Itching (pruritis) • Flushed skin • Rash or hives (urticaria) • Watery, reddened eyes • Nasal congestion • Increased heart rate • Tingling in/around mouth • Fatigue

13. Moderate Allergic Reaction • Effects include those in a mild reaction, but more pronounced. • The respiratory and gastrointestinal system are usually involved. • Symptoms may take minutes, hours, or even days to develop. continued

14. Moderate Allergic Reaction • Effects might disappear over time, or increase in severity, depending on individual chemistry and response. continued

15. Moderate Allergic Reaction Signs and Symptoms • Anxiety and confusion • Tightness in the throat • Difficulty swallowing and/or breathing • Wheezing • Rash, hives, swelling in face, neck, chest, arms continued

16. Moderate Allergic Reaction Signs and Symptoms • Persistent itching • Angioedema • Abdominal pain or cramping • Nausea and/or vomiting • Elevated vital signs

17. Moderate Allergic Reaction continued

18. Severe Allergic Reaction • Causes a massive inflammatory response in the respiratory, integumentary, circulatory, and gastrointestinal systems due to massive histamine release. • Effects are almost immediate- within seconds or minutes. • If not treated quickly, it can lead to anaphylactic shock and/or death. continued

19. Severe Allergic Reaction Signs and Symptoms • Severe anxiety, impending doom • Decreased level of responsiveness • Severe respiratory distress; • Severe angioedema, hives • Abnormal lung sounds • Inability to swallow continued

20. Severe Allergic Reaction Signs and Symptoms • Tachycardia, weak peripheral pulses • Hypotension, pallor, cyanosis

21. Preventing Allergic Reaction • Triple A Approach: • Awareness – of one’s allergies and the triggers • Avoidance – of contact with known allergens • Action – know what to do if an allergic reaction occurs (emergency and self-care)

22. Case Update • She looks pale and appears to be in mild respiratory distress. Once you determine that the ABCDs are intact, you notify dispatch to send additional personnel with oxygen and an airway kit. You also request that an ALS provider respond. Respirations are 38 per minute and labored. The patient’s face appears swollen.

23. Assessment • Moving patient may be necessary before assessment. • Severity of allergic reaction determines timing, esp. if anaphylaxis is present. • Observe closely skin, face, neck, and eyes for rash, swelling, breathing. • Extend questioning during known allergies part of SAMPLE (EpiPen)

24. Management • Initial management is similar- ABCDs. • Try to identify the allergen. • Remove the patient from the allergen if possible. • Monitor and check vitals frequently. • If signs of anaphylaxis appear, treat ABCDs and seek transport and ALS. • Insect bite? Remove stinger if possible.

25. Management

26. Epinephrine • Drug of choice for managing severe allergic reaction. • Promotes bronchodilation and vasoconstriction to relieve dyspnea and hypotension. • Comes pre-packed in adult and pediatric doses (“EpiPen”). continued

27. Epinephrine • Those with severe allergies will often have an EpiPen with them. continued

28. Epinephrine

29. Epinephrine

30. Case Disposition • Other OEC Techs soon arrive with oxygen and a wheeled litter basket. You place the patient on a nonre-breather mask at 15 LPM. You locate her EpiPen™ and assist her in administering the medication in the lateral side of her thigh. Within a few minutes, she is breathing more easily, and her facial swelling begins to diminish.

31. Chapter Summary • An allergy is the body’s overreaction to a foreign substance. • Allergies are caused by antigens called allergens. • Many people do not know they have an allergy until they suffer • an allergic reaction. continued

32. Chapter Summary • Tongue swelling is an ominous sign of an allergic reaction. • Anaphylaxis can be fatal unless rapidly treated. • Peanuts are the number one food allergy in the world. • Allergic reactions may be prevented using the Triple A approach.

33. Chapter Summary • Triple A Approach: • Awareness – of one’s allergies and the triggers • Avoidance – of contact with known allergens • Action – know what to do if an allergic reaction occurs (emergency and self-care)