Anaphylaxis

Definition

  • Severe, rapidly progressing and potentially life-threatening allergic reaction that involves multiple organ systems.
  • Common triggers: bees, wasps, hornets, fire ants, tree nuts, milk, eggs, fish, shellfish, latex, medications.
  • Hiker may have a previous history, or may have new onset, even if previously exposed to the allergen without history of reaction.
  • Generally occurs within minutes to hours of exposure (most within 1 hour of exposure).

Symptoms

  • Itching, skin rash, hives
  • Swelling of face, lips, tongue
  • Feeling of fullness in the throat, cough, clearing throat, hoarseness
  • Shortness of breath, wheezing, respiratory distress
  • Rapid heart rate
  • Feeling faint due to drop in blood pressure
  • Abdominal cramps, vomiting

Management

  • Any hiker with a known history of anaphylaxis should ALWAYS have an EpiPen to carry. Should not participate in the hike otherwise; Hike Leaders should include this in Trailhead talk.
    • If hiker cannot administer their own EpiPen, someone else on the hike will need to locate it and administer it, preferably to the front outer side of a thigh.
    • If reaction is new-onset and no EpiPen available, an oral anti-histamine can be given (Benadryl/ diphenhydramine, 50 mg if patient is awake and can swallow) but is not a substitute for epinephrine (EpiPen). Benadryl can also be given after Epipen use.
    • Gently scrape stinger off of skin, if visible.
  • Have hiker sit or recline back with feet elevated if feeling light-headed.
  • Monitor for ABCs (Airway, Breathing, Circulation) and initiate CPR if necessary.

 

(Sources: “Anaphylaxis”, NIH/National Library of Medicine, 1-2023; “Wilderness Medical Society Clinical Practice Guidelines on Anaphylaxis”, 3-2022.)

The information provided on this CVHC page is for general informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment.