Although I would agree that one should not give a pill or liquid to someone with a swollen airway, anaphylaxis can occur without airway involvement. More importantly, however, I don’t believe that training to inject an antihistamine is necessary or worthwhile.  The treatment for anaphylaxis is epinephrine, period.  If you had nothing else, that would be okay.  Except for hives, antihistamines do little for the acute symptoms.  In fact, no one has clearly demonstrated that they are even necessary.  We use them in the hope that they will decrease the likelihood of a biphasic or rebound reaction.

Q: We are moving from epi auto injectors to epi vials and I am working on updating our protocol.  Do you have a protocol for vials?

The protocol for treatment would be the same except for the actual steps of drawing up the medication.  You might want to consider a policy that addresses purchase, storage, disposal, training (I would refresh yearly), monitoring for expiration dates, and usage review (all allergic reactions whether or not meds were used).  With vials, I would suggesting adding that each should be discarded after being used for an episode of anaphylaxis (however many are needed for the episode).  With amps, I would use each for one injection.  In both cases, medication will be wasted but you will decrease the likelihood of contamination.  Given the relative costs compared to autoinjectors, they still remain very cost effective.

Click here to access the Wilderness Medical Associates’ Field Protocols, including Protocol 1: Anaphylaxis.

If you are trained to identify anaphylaxis and properly use the device, I would argue, yes.  I have been reviewing the experience of organizations that sponsor our courses.  Even at the first aid level more then a few have used epinephrine accurately and successfully.   Although less frequently, they have administered epinephrine in circumstances where a person with a history did not have the injector and in people who have not had a reaction previously.

I would argue that epinephrine use is first aid for properly trained individuals working in remote environments.  The major problem is state law.  I don’t know the rules, if there are any, in CA.

If you decide to use epinephrine, make sure that you do your due diligence and have a workable and useful risk management process.  Make sure everyone is trained.  You might consider including a yearly review.  Have a good way to store the med, monitor its expiration date and properly dispose of expired and used injectors.  Also, engage whomever writes your prescriptions to review every instance where it is used.

A:  Be direct and honest.  Outline your training and your intentions.  If your doctor has any questions direct her/him to the resources section our website for the Wilderness Medicine Field Protocols.

A:  Thanks for the query.  Simply put, delivering the proper dose of epinephrine using this mixture would require a large volume and a toxic dose of lidocaine.  If you do the math, you would need 60 mL to administer 0.3mg of epinephrine which would include 1200 mg (1.2 gm) of lidocaine.  Anything over 300 mg of lidocaine is considered potentially toxic in an adult.

Could this combination help with a stingray puncture?  Lidocaine is a local anesthetic used for suturing so theorectically it could help to temporarily ease the pain if injected locally.  But remember, injecting lidocaine is not part of the scope of practice of a WFR and would therefore be a real stretch.  Besides, immersion in hot water works quite well.

A: The symptoms of anaphylaxis are related to chemical mediators that result in direct stimulation of target organs and inflammation.  Epinephrine works quickly and directly to constrict vessels and dilate lower airways.  It also helps to decrease the release of these chemical and inflammatory mediators from mast cells and basophils.  Although epinephrine is oftentimes sufficient treatment for anaphylaxis, we add antihistamines and corticosteroids to sustain the effect and help prevent recurrences (e.g., biphasic reactions).

Antihistamines are slower acting.  Though not as potent or effective as epinephrine, they help block the effects of mediators that have already been released.  Prednisone, a prescription medication, is a corticosteroid that binds to receptors to help modulate inflammatory responses.  Because of their delayed onset of action (4 – 6 hr) the real purpose of prednisone is to help decrease the chance of a biphasic reaction by suppressing inflammation.  Interestingly, this is a different sort of anti-inflammatory effect from what we see with non-steroidal anti-inflammatories (NSAIDS) like ibuprofen.  In fact, in some people the NSAIDS actually stimulate the production and therefore the concentration of some of the mediators of inflammation that are responsible for the symptoms of anaphylaxis.  DON’T substitute a NSAID for prednisone in anaphylaxis.

Bottom line: Prednisone is an important adjunct in the management of anaphylaxis, especially where an evacuation is many hours away.  For a dose or 2 in a person not allergic to them (yes, people can be allergic to prednisone), prednisone offers an excellent insurance policy.  For most programs I would consider it to be optional.

A: You are not alone in your confusion.  One of the beauties (in a mysterious way) and perils of medicine is that logic does not always work or at least it becomes complicated and convoluted.

There are different kinds of receptors for specific chemicals; their locations vary by end organs.  In turn, not all end organs have the same distribution of these sites.  Although histamine is the quintessential mediator, there are a variety of others that either act directly or stimulate the release of other mediators resulting in organ responses and/or inflammation.  Responses are therefore dependent on the mediators and the location of the receptors.

As I understand it, vascular dilation and change in permeability is at the capillary bed level and is direct, perhaps related to nitric acid.  This is not a smooth muscle issue.  On the other hand, bronchoconstriction is based on muscular spasm and swelling the occurs as a result of fluid accumulation from leaky, dilated vessels in the bronchial capillary beds.

Epinephrine has its major effects directly via vascular constriction and bronchial dilation and indirectly by halting vascular leakage.  Epinephrine also helps to stabilize the mast cells from which histamine and other mediators are released.  The effects of antihistamines is more local and slower.

Bottom line: Don’t lose the forest for the trees.  Epinephrine works.

Good question.

If the symptoms are isolated to the lower airways as manifested by wheezes, an inhaled Beta agonist like albuterol will probably help with the symptoms.  But remember that unlike asthma, anaphylaxis is a systemic, not a local, problem.  In anaphylaxis chemical mediators are released in the circulation and then migrate to sites around the body.  Albuterol works locally and will have no effect on the generation of these mediators.  If the manifestations are shock or upper airway obstruction (the two most lethal manifestations of anaphylaxis), the albuterol will not be useful.

Equating an allergy to shellfish with an allergy to iodine is a fairly common misconception.  Fish and radiographic contrast allergies are also erroneously equated with iodine allergies.

Iodine is essential for proper thyroid function.  Without it, people become ill with thyroid problems.  As it turns out, seafood and crops fertilized with seaweed are a good source of iodine.  As people moved from coastal areas inland, the incidence of thyroid deficiency increased.  Beginning in the 20th century, it became a common additive in many varieties of table salt.  As a result, now you have to work hard to completely avoid it.

The allergen in shellfish is a protein, not iodine.  Some people with iodine allergies really have a topical sensitivity to iodine (e.g., povidone iodine; Betadine), usually a much different kind of reaction than the immediate reaction found with anaphylaxis.

Bottom line: A shellfish allergy should almost never preclude the use of iodine for water disinfection. If you are concerned, get more information about the true nature of the allergy.  If the person has not had problems with other seafood (saltwater) or table salt, iodine is not the culprit.  There are, of course, other reasons for not using iodine as a water disinfectant.

After spending some time and given the resources I have at hand, I cannot give you a satisfactorily accurate answer.

Hydrocortisone is available in a pill form and is used particularly by people whose adrenal glands are absent or not functioning properly.  In this form it is rapidly absorbed in the gut.  4 mg of hydrocortisone equals 1 mg of prednisone.

Hydrocortisone is sold for topical use (on the skin) either as 0.5 or 1% creams or ointments.  1 gm of 1% topical hydrocortisone is equal to 10 mg of hydrocortisone.  That would give you nearly 300 mg in a 1 ounce/30 gm tube or, theoretically, the equivalent of 75 mg of prednisone.  What I don’t know and what I was unable to find out easily is what happens to hydrocortisone topicals on ingestion.   The cream is water soluble so, at least theoretically, it is more easily absorbed in the gut than the ointment. In addition, I could not find any pharmacokinetic (movement of a drug through the body) data about rates of absorption from the gut or subsequent blood levels and I have no idea what happens with either when exposed to digestive enzymes.  Aside from nausea and vomiting or diarrhea, the poison control literature suggests that a mouthful is not likely to be toxic.

So yes, theoretically, it could help but any potential effect would be unpredictable.  By the way, a tube cost about 5$US; thirty 20 mg tablets of prednisone tablets are less than 10$US.  I think you know what I would choose.