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Anaphylaxis:
Anaphylaxis, a life-threatening allergic reaction to things like wasp or bee-stings, peanuts, or other foods.
Symptoms develop rapidly, often within seconds or minutes up to 30 min..
The most immediate danger is swelling (angioedema) in the throat or tongue that may be severe enough to block the airway.
Other symptoms may include:
  • Wheezing or Abnormal (high-pitched) breathing sounds
  • Generalized itching, particularly palms, armpits and groin or nettlerash (urticaria, hives).
  • Swelling of the eyes or face, Skin that is blue from lack of oxygen or pale from shock.
  • Anxiety, Confusion, weakness
  • Abnormal heart rhythm (arrhythmia or palpitations), Rapid pulse
  • Nasal congestion, Nausea, vomiting
  • Diarrhoea

The slower the onset of the reaction, the less likely it will be anaphylactic.

There are several acute conditions can be confused with anaphylaxis.

  • Rrespiratory distress syndromes
  • Recent inhalation of foreign bodies (airway obstructin)
  • epileptic syndromes with predominant hypotonia (decreased muscle tone which can be caused by trauma, environmental factors, central nervous system disorders, ...)
  • heart attacks
  • anxiety attacks
If the patient had a recent exposure to a known allergen anaphylaxis is an easier diagnosis.

Treatment:

The Asthma & Allergy Information Research (AAIR) in the UK recommends the 3D rule for deciding to administer epinephrine.

  1. Definite reaction: evidence of a reaction should be obvious.
  2. Deterioration: the aim is to inject BEFORE life is in immediate danger. If the reaction is improving by the time you get the adrenaline (epinephrine), just keep the adrenaline (epinephrine) handy for six hours in case it gets worse again.
  3. Death seems any sort of possibility if the deterioration continues another 5 to 10 minutes.

Steps:
  • Give an antihistamines, such as diphenhydramine (e.g. Benadryl), which should take effect in 15-30 min.
    Liquid benadryl will take effect sooner or you can grind up pills.
  • If patient shows signs and symptoms of anaphylaxis (swollen face, lips and tongue; difficulty swallowing; systemic hives; respiratory distress; inability to speak in more than one or two word clusters; signs and symptoms of shock) administer epinephrine:
    • Call 911
    • Administer epinephrine, a synthetic adrenalin, with an epipen®. See below.
  • When the patient is again able to swallow, they should take an oral antihistamine.
    Considering that rebound reactions can happen as quickly as 10 to 15 minutes after the initial injection, additional Epipens and oral antihistamines must be considered in remote camps and especially wilderness trips.
Epinephrine treats the immediate life threatening effects of anaphylaxis, but not the underlying problem, which is an abnormal immune response causing a release of histamine.
In the US, the incidence of anaphylaxis from hymenoptera stings is estimated to be between 1-5% of the population.
Food allergy affects up to 6% of children.
Anaphylaxis only develops in persons already sensitized to the venom but they may not recall a previous exposure history.

- Primatine mist is an over the counter inhaler that has epinephrine in it. It also has a much longer shelf life.

EpiPen®

  • An EpiPen® injects epinephrine a synthetic adrenalin.
  • Should be used only when your thinking "I cant breathe and I am going to die" or "I really need to go to the emergency room".
  • 25-30% of the time a second severe reaction can occur within hours of the first. This is known as a biphasic reaction and requires a second dose of epinephrine.
    symptomatic patients should be observed for at least 3 - 6 hours after symptoms are controlled.
  • Note: up to 90% of the epinephrine liquid stays in the auto-injector once it has been used.
  • A dose may wear off after 15-20 minutes.
    If you are in a remote area, you should carry more than one dose
  • The EpiPen is designed to be injected into the outer mid-thigh only and can go thru clothes. (thigh area means take fist with thumb out,hold at side and press against leg naturally) press black knob against this area firmly. You will hear a snap..hold for 5-10 seconds..remove.
    You can rub the injection site for more rapid absorption.
  • EpiPen Auto-Injectors should be used with extreme caution in people who have heart disease or anyone over 50. Side effects of EpiPen Auto-Injectors may include fast or irregular heartbeat, nausea, and breathing difficulty. Certain side effects may be increased if EpiPen Auto-Injectors are used while taking tricyclic antidepressants or MAOIs.
  • Children:
    EpiPen JR is recommended for children 22-66 lbs
    4 Steps in using the EpiPen with children (see EpiPen Use at the Children's hospital at Westmead, Australia)
    1. Form a fist around EpiPen and pull off grey cap (do not twist). Before pulling off the grey cap you should check that your thumb is closest to the grey cap end, and not over the end of the EpiPenĘ, as in the picture. This will help prevent you from placing your thumb over the black 'active' end.
    2. Place black tip against outer mid-thigh of the child. (Note; there is no need to 'swing and jab' which may cause the child to jump and pull away.)
    3. Push HARD until a click is heard or felt and hold in place for 10 seconds
    4. Remove the EpiPenĘ and then call an ambulance. The EpiPenĘ can only be used once.
    A group of paediatricians in the UK suspects that the dangers of adrenaline in children under 16 do indeed outweigh the benefits. They are initiating a study on this.
Care of Epipen
  • Recommended storage temperature is 60 - 86° F; do NOT refrigerate.
  • Protect it from light
  • A typical expiration range is between 12 and 16 months from time of purchase.
    Apparently most pharmacies receive their yearly EpiPen shipment in March.
    If, however, the only autoinjector available is an outdated one, it could be used as long as no discoloration or precipitates are apparent because the potential benefit of using it is greater than the potential risk of a suboptimal epinephrine dose or of no epinephrine treatment at all.
  • Often the adrenaline (epinephrine) solution goes yellow or brown when it is becoming useless, but you can't rely on this.
EpiPen Instructions at PeanutAware.com
Anaphylaxis at about.com
First Aid at Mayo Clinic
epipen.com
Anaphylaxis Treatment Guidelines from EpiPen®

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last updated 11 June 2007