Allergic Reactions & Envenomations

• 1,000/yr die of allergic Reactions
• Allergic Reactions - Be Aware of:
  • Acute Airway obstruction
  • Cardio-vascular collapse
  • Distinguish between body's usual response vs Allergic Reaction

5 Categories of Stimuli that may provoke Allergic Reaction

• Insect Bites & Stings
• Medications
• Plants
• Food
• Chemicals

Allergic Reaction

• Caused by a reaction in the body's immune system which releases chemicals to combat the stimulus:
  • Histamines
  • Leukotrienes
• May be mild and local
• May be severe and systemic

• Anaphylaxis - extreme allergic reaction that is usually life-threatening, and typically involves multiple organ systems
• 2 of the most common signs of Anaphylaxis are:
  • Wheezing
  • Wide-spread urticaria (hives)

• Inject venom - envenomation
• Honey Bee, Wasp, Ant, Yellow Jacket, Hornet:
• Reaction may be local or systemic
• More than 100,000 bees, etc.
• Deaths from these far outnumber deaths from snake bites
• Stinger from Honey Bee - barbed - dies after flying away
• Wasps and Hornets can sting repeatedly
• Often difficult to determine which species was responsible

• Fire ants strike repeatedly (multiple ant bites on feet and legs - usually)

• Sudden Pain
• Swelling
• Localized Heat
• Redness (light skinned individuals) at site
• Itching
• Wheal - hives

• Ice the area - not directly in skin
• Use a credit card to scrape off stingers
• Gently wash the area
• Remove jewelry before swelling begins
• Position injection site slightly below the level of the heart
• Be alert for vomiting, shock, or allergic reaction
• Nothing via mouth
• Patient in shock position
• Oxygen, as needed

• 5% allergic
• More than 2/3 die within the 1^st 1/2hr.
• Provide:
  • Oxygen
  • Epi - life-threatening

• General Impressions
• May be present as:
  • Respiratory distress
  • Cardio-vascular distress
  • If anxious and in Distress - call for ALS
• May have medical tag

• Rapid swelling of upper airway
• May have only a few minutes to assess and treat
• Not all allergic reactions are anaphylactic reactions
• Position patient in tripod position
• Listen to lungs
• Wheezing - lower airways are closing
• Initiate High-Flow Oxygen
• Assist w/ ventilation (positive pressure)
• Administer Epinephrine

• Palpate a radial pulse
• Patient is unresponsive - no pulse - begin CPR
• Use AED if needed
• Assess for rapid heart rate
• Pale cool, moist skin, delayed capillary refill times
• Initial treatment for shock should include oxygen, shock position, maintain normal body temp.
• Epinephrine

• Prompt
• Take all medications and auto-injectors patient has

• If Unresponsive - Rapid Physical Exam
• Responsive - SAMPLE
• What interventions have been completed
• Any prescribed, preloaded, medications
• Perform focused exam looking for stingers or contact with chemicals or other indications 
• Obtain a complete set of vitals

SAMPLE

Symptoms 

Condition can rapidly deteriorate

Allergies - may have history

Medications - what do have, what have they used

• Evaluation:
  • Respiratory 
  • Circulatory
  • Mental Status
  • Skin
  • LOC

• Prolonged respiratory difficulty can cause:
  • Rapid heart beat
  • Shock
  • Death
  • Stridor - inspiratory sounds - swelling in upper airway - being closed off (total obstruction)

• Check skin for:
  • Swelling
  • Rash Hives
  • Bite, sting, contact marks
• A rapidly spreading rash can be concerning - systemic reaction
• Red, Hot Skin - may also indicate systemic reaction - blood vessels lose ability to constrict

• Rapid, Labored Breathing indicates airway obstrction
• Rapid respiratory and heart rates - may indicate respiratory distress, or systemic shock
• Fast Pulses and hypotension - ominous signs - systemic vascular collapse ans shock

• Identify how much stress the patient is in
• For severe reactions:
  • Ventilation support
  • Epinephrine
• Milder Reactions:
  • Oxygen - high flow