Suppose you are out hiking, many hours from the trail head and someone has a severe allergic reaction (ie, anaphylactic shock or Anaphylaxis). In this case, what is the best course of treatment to maximize their chance of survival until they can reach a hospital?

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    Anyone care to share feedback on the reason for the downvote? :) – Russell Steen Apr 13 '16 at 17:16
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    I feel so frustrated when I get a no-explained downvote +1, downvotes are supposed to be a heads up – Kyle Apr 13 '16 at 17:36
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    Normally I don't care, but I actually consider this to be a fairly important question and would like to improve it if there are flaws. – Russell Steen Apr 13 '16 at 21:15
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    I don't see a reason for a downvote either, have a +1 from me. – Olin Lathrop Apr 14 '16 at 12:01
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    The internet is not a valid source of medical advice. I'm afraid some amateur (and probably dumb) hikers could take what is written on this page at heart and then someone gets hurt or worse. – Mindwin Apr 14 '16 at 13:31

Anybody who has severe allergies which could lead to anaphylaxic shock should carry appropriate medication with them. Typically, that would consist of:

  • An antihistamine (e.g. benadryll)
  • An epinephrine auto-injector (aka "Epi-Pen")

Benadryll is available over the counter and you should have it in your first aid kit. Epi is by prescription only (at least in the US), so the individual who has allergies should carry their own. If you're leading a large group, you may be able to get a prescription and standing orders for trained staff to carry and administer epinephrine to group members.

Many people think that just injecting epi when somebody has an anaphylactic attack is the entire treatment. It's important to know that epinephrine does not fix the underlying issue! It only helps to reduce swelling, helping to re-open the airway. You must fix the cause of the reaction!

As soon as an exposure to a known allergen occures – even if the person isn't having a visible reaction – you need to immediately have the person take an antihistamine. Antihistamines are drugs that suppress the histamine response, i.e. the body's overreaction to an antigen. This is what actually reduces the severity of the allergic reaction itself. Correct dosage depends on the person; consult the instructions on the antihistamines or talk to a doctor.

The important consideration with an allergic reaction is maintaining a clear airway. If you get the antihistamines into the patient immediately, it's possible that the reaction will be contained and the patient will not develop anaphylaxis. In the event that they do develop anaphylaxis, that's where you need to monitor their airway and administer epi if necessary. If the patient is having difficulty breathing, encourage them to take deep, calm breaths, and to pace their breathing off yours.

If the patient is unable to maintain a clear airway, be prepared to administer epinephrine. Epi-pen trainer kits are widely available through first aid training programs, so if you expect to be traveling in the wilderness with people who may require epi, you should do the training. The auto-injectors have clear instructions on them; typically you just remove the blue cap, place the orange end of the auto-injector on their thigh, push down hard on the epi-pen to trigger the injector, and hold it in place for at least 30 seconds. The epi is administered automatically at the correct dosage. Make sure to carefully follow the directions as individual auto-injectors may vary in how exactly they are administered. Epi wears off after 10-15 minutes, so most people will carry either a dual-injector or two injectors, so that a second dose can be administered if necessary. When injecting, always hold the injector gripped in your fist, do not place anything over either end of the pen to ensure you don't accidentally inject it into yourself!

epi pen

Make sure to monitor the patient's vital signs throughout, and continue to monitor their condition after the initial treatment. Ensure that any secondary issues such as bleeding from a bite, etc. are taken care of as well.

Once you've stabilized the patient, you need to start planning for an evacuation. Anaphylactic reactions are life threatening. If you are in a very remote area and have access to an emergency locator beacon or other outside communication, it's appropriate to request emergency assistance.

As always, the most important thing is to be adequately prepared. Understanding the allergies (and other medical concerns) your group members have, what treatment options they have, and how to use them is critical. You should know all of this information for every member of your party before heading into the wilderness, so that if an emergency situation does arise you're already prepared. Most people with medical concerns which could require your immediate intervention will be happy to show you how to handle it should they need your help. In this particular example, epi injectors differ in appearance and operation, and knowing exactly how to use the injectors belonging to members of your party will save you precious time should you actually need to use them.

Note: This information is based on my training as a wilderness first responder and the accompanying textbooks and practice. Reading medical advice on the internet is no substitute for proper medical training. This information is provided as-is, with no guarantee of correctness or effectiveness. You alone are responsible for ensuring an appropriate level of training for the activities you engage in, including administering first aid to yourself and others. Neither Stack Exchange, the author, nor any other party shall be responsible for any harm that comes to you or others by following any advice in this post.

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    Blue to the sky, orange to the thigh! – corsiKa Apr 13 '16 at 19:03
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    It is worth noting that Epi-Pen is a brand product and the name of only one companys injector, other common brands of injector are things such as anapen etc. Which look different to the one in the picture. So you should always read the instructions on the injector before use if you are unfamiliar. – Sean F Apr 14 '16 at 7:23
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    Just to point out, most auto-injectors require you to hold the pen to the thigh for 15-30 seconds to deliver the correct dose. Stabbing and quickly removing the injector will not work optimally – Gremlin Apr 14 '16 at 9:01
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    @nhinkle - given that this is potentially life-and-death information, perhaps you could edit your answer to explain your credentials? It would be helpful to know your background in the field. – Tullochgorum Apr 14 '16 at 20:43
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    @Tullochgorum As someone with severe allergies who has visited an allergy doctor/immunologist in the last few weeks and discussed anaphylaxis, I can confirm that nhinkle's information is correct. Really, most people with severe allergies already know all this. – BenjiWiebe Apr 15 '16 at 4:03

An epi-pen buys you 15 to 30 minutes. You can follow up with benadryl for other antihistamine. But the patient needs to understand what to do. For a back country activity the patient needs sufficient antihistamine to get over the incident or back to medical facility.

This is a serious incident. I have worked with people who were seriously allergic to bee stings. When they got stung, it was, "epi-pen NOW. Drive me to a hospital. Watch me for relapse, here's the second epi-pen if I stop breathing"

One other person I knew was so allergic she had a pen in each car, bathroom, and in her purse. That way she had 2 to get her to the hospital.


Although an epi-pen-like device is the correct treatment for anaphylaxis, if the patient's airway is becoming obstructed, and adrenaline is not available (or has already been expended), several puffs (some sources say 8-10) from an asthma inhaler intended for treating an acute asthma attack, particularly one containing salbutamol (also known as albuterol), can provide some relief. Ideally, it should be delivered through a spacer.

In my experience, more people carry asthma inhalers than epi-pens. However, this should only be done when the patient's airway is swelling and potentially becoming obstructed (they will have a wheeze or difficulty moving air). In this case, the consequences of doing nothing may include the patient dying. Giving a drug to a patient who doesn't usually take it is not a good idea, as there's a risk of adverse reaction from the drug itself. Salbutamol also increases the heart rate. You should still seek emergency help.

Salbutamol is a bronchodilator, and will dilate the airways in the lungs, but will not help to relieve an upper airway obstruction.

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    this should only be done when the consequences of doing nothing may include the patient dying Why this dire warning? What are the potential negative consequences? – RockPaperLizard Apr 15 '16 at 0:58
  • The only common negative side-effect is a slightly elevated heart-rate. It can induce higher levels of activeness in children, but the general advice with salbutamol is that it should be given if there is even a slight chance it might help. I am not sure why this line was in the answer. – mwotton Apr 15 '16 at 3:35
  • @RockPaperLizard My asthma inhaler is albuterol, so I'm not aware of how salbutamol works (probably much the same though). When I use even two puffs of albuterol, I get a very noticeably elevated heart rate. I would be afraid of doing damage with too many more puffs... – BenjiWiebe Apr 15 '16 at 4:05
  • Albuterol is another name for salbutamol. I inlcuded a warning that it should only be used for a potentially deadly situation (like an obstructed airway) because of the side effects of increased heart rate/BP and the possibility of an adverse reaction to the drug itself – Gremlin Apr 18 '16 at 8:14

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