Two DIY Tests for Food Allergies During TEOTWAWKI

Disclaimer.  I am not a licensed health practitioner.  This is just another post on knowledge and understanding you might wish to acquire in advance of a disaster in case no higher care is available.  As long as our society is functioning, you should leave anything more substantial than applying a Band-Aid to the professionals.  No medication, including those available over the counter, should be taken without consulting a physician.  Information shared here is for educational and entertainment purposes only.  It is not medical advice nor a substitute for licensed medical care. 


Let's say, for argument's sake, that TEOTWAWKI has already happened.  Physicians, hospitals, and laboratories are next to non-existent.  You are pretty much on your own.

Now let's say that shortly after Sunday dinner, your child starts experiencing some intestinal discomfort or breaks out in hives.  You suspect a food sensitivity or allergy, and you don't want a repeat.  However, there were nearly 30 different ingredients in the soup, salad, rolls, and cookies.  How are you going to figure out what the offending food might be?  And how are you going to determine whether it's a true allergy or merely a sensitivity?  And, does it matter?

A true allergy invokes an anaphylactic response where the body has the potential to go into shock.  Death is a real possibility.  While any food or substance can trigger an allergic response in any person at any time, the most common foods that trigger anaphylactic responses are peanuts and tree nuts, though eggs and milk are also common food allergens.  If you suspect any type of nut to be the culprit, do not attempt testing without a physician to supervise.

Dietary challenge

1. Avoid the suspected food for at least 4 days.
2. Wash the suspected food well if it is fresh produce.  Some people have sensitivities to pesticide residues or other products used in agriculture. 
3. Eat a moderate amount of the suspected food on an empty stomach (nothing more than water in last 2-3 hours).
4. Take the pulse rate before and after eating the food in question.  Calculate the difference.  If the pulse rate rose more than a few beats per minute, an allergy is likely even if no other symptoms are present.
5. Rashes also point to allergies.
6. Fatigue, insomnia, headaches, joint pain, and hoarseness suggest sensitivities.[1]

Skin scratch test

1. Use the inner forearm and upper arm for this test.
2. Clean the skin area with soap and water and then wipe with rubbing alcohol.
3. Apply a little saline to one small site and then scratch the area with a butter knife or similarly dull instrument.  You do not want to break the skin or cause bleeding.  You shouldn't even see any flakes of skin removed.  This is the control site.  There should be no reaction.  (Another control that would be performed in a clinical setting would be to apply histamine to another site.  Everyone should react to histamine; unfortunately, it's not something we're likely to have at our disposal.) 
4. Mash the food in question and apply a small amount to another prepared skin site that has been washed, disinfected, and scratched as described in the previous step.  
5. Leave it in place for 20 minutes and then rinse it away.  There should be no difference between this site and the control site if there is no allergy or sensitivity.
6. Itching, irritation, bumps, or redness suggest a sensitivity or allergy.  A positive test will look like the irritation following a mosquito bite and may be a little red.  An itchy bump may form.  If the food is causing a problem in the skin, it is also likely causing a problem internally and should be avoided.  However, these tests are not considered diagnostic or definitive.  They only suggest a possible problem.

Keep in mind that if an individual is using antihistamines, this test will not work.  The antihistamines (Benadryl, Zyrtec, Allegra, etc.) block the histamine (allergic) response.  

While a person can have an allergic reaction to any product at any time, some foods have greater reputation for causing anaphylactic reactions than others.  (Yeah, I know I just said this a little bit ago, but some things have to be emphasized.)  If you suspect an allergy to any nuts, eggs, penicillin, or latex, this test should truly only be performed under a physician's supervision and with an Epi-pen at hand.  While other substances are less likely to cause an anaphylactic reaction, and may more reasonably be tested at home using these procedures, having an Epi-pen on hand is still a good idea.  In addition, persons with a history of anaphylactic reactions are more likely to react to other allergens as well.  Allergy tests in these individuals should also only be conducted with a physician's supervision and epinephrine close at hand.

What about a drug allergy?  The most common drug to cause an allergic reaction is penicillin.  It's also a commonly used antibiotic, and it is the drug of choice in treating some serious infections.   Interestingly, a penicillin allergy often passes with time.  In a situation where a patient may have a penicillin allergy and has an illness that is best treated with penicillin, the procedure for performing the DIY skin test is the same as above:

• Grind up a penicillin tablet or open a capsule.  
• Mix the powder with a little water and apply the paste to the skin.
• If there is a reaction, that person is truly allergic and penicillin must not be used.
• If there is no reaction, penicillin may be used if absolutely necessary, under a physician's supervision, and with an Epi-pen close at hand.[3]

Links to related posts:
Alternative Uses of Benadryl
Epinephrine--Is It a Must-Have or a Nice-to-Have in the Emergency Kit?
Allergic to Penicillin?  What Are the Options?
Penicillin Primer for Preppers

References:
[1] https://www.thehealthyhomeeconomist.com/steps-for-at-home-allergy-testing/.
[2] https://haleynutrition.com/skin-allergy-testing/.
[3] Survival and Austere Medicine, 3rd Edition, 209.

9.8.20