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By Michelle Dillinger
EMS Emergency Medical Services, badges article logo labelLaw Enforcement chiclet article type logo label

Scientists are still trying to figure out why food allergies seem to be on the rise (1), especially in industrialized countries such as the United States. Are children not getting exposed to enough bacteria? Should they eat common allergens such as nuts and shellfish at an earlier age?

Researchers took a look at thousands of cases in emergency departments globally. They did not rely on the diagnosis given at that time, but made their own determination about whether an allergic reaction had occurred based on symptoms such as hives. That means the rise in reactions probably did not have to do with an increased awareness among doctors.

One theory is that the Western diet has made people more susceptible to developing allergies and other illnesses since they tend to shelter their children from germs, bacteria and pollutants, which research shows to be a factor in many regions around the world (1).

"A study in Proceedings of the National Academy of Sciences compared the gut bacteria from 15 children in Florence, Italy, with gut bacteria in 14 children in a rural African village in Burkina Faso ... They found that the variety of flora (5) in these two groups was substantially different. ... Their findings support the widespread notion of the 'hygiene hypothesis' -- the idea that cases of allergies are increasing in number and severity because children grow up in environments that are simply too clean" (1).

"That our immune system is slanted away from fighting infections and tilted towards fighting things that it's not supposed to be fighting, like things in the environment or foods -- that's one opinion researchers believe may be in play."

Another theory that children need to be exposed to common allergens, such as nuts and shellfish, from a much earlier age, is to avoid developing allergies later in life. Some doctors have been recommending waiting until 2 or 3 years of age, but Dr. Ferdman at Children's Hospital of Los Angeles is a proponent of giving kids nuts at a very early age. This study is supported by an often-cited 2008 study in the Journal of Allergy and Clinical Immunology which compared peanut allergies among Jewish children living in Israel and the United Kingdom. Peanut allergies were more common among the children in the U.K. than in Israel. This was associated with the fact that 69 percent of the Israeli children received peanuts by 9 months of age, compared with 10 percent of the infants in the U.K.

Allergy Statistics:

Drug Allergy

   •    Worldwide, adverse drug reactions may affect up to 10% of the world's population and affect up to 20% of all hospitalized patients (3)
   •    Worldwide, drugs may be responsible for up to 20% of fatalities due to anaphylaxis. (3)

Food Allergy

   •    Findings from a 2009 to 2010 study of 38,480 children (infant to 18) indicated 8% have a food allergy (3)
   •    Approximately 6% aged 0-2 years have a food allergy
   •    About 9% aged 3-5 years have a food allergy
   •    Nearly 8% aged 6-10 years have a food allergy
   •    Approximately 8% aged 11-13 years have a food allergy
   •    More than 8.5% aged 14-18 years have a food allergy
   •    38.7% of food allergic children have a history of severe reactions
   •    30.4% of food allergic children have multiple food allergies
   •    Of food allergic children, peanut is the most prevalent allergen, followed by milk and then shellfish
   •    In 2012, 5.6% or 4.1 million children reported food allergies in the past 12 months. (3)

General Allergy

   •    Worldwide, the rise in prevalence of allergic diseases has continued in the industrialized world for more than 50 years. (3)
   •    Worldwide, sensitization rates to one or more common allergens among school children are currently approaching 40%-50%. (3)
   •    In 2012, 10.6% or 7.8 million children reported respiratory allergies in the past 12 months (3)

Insect Allergy

Worldwide, in up to 50% of individuals who experience a fatal reaction there is no documented history of a previous systemic reaction. (3)


Anaphylaxis is a potentially life-threatening allergic reaction. It may occur within seconds or minutes of exposure to something you're allergic to, such as peanut butter or venom from a bee sting.

The flood of chemicals released by your immune system can cause you to go into shock; your blood pressure drops suddenly and your airways narrow, blocking normal breathing (1). Symptoms of anaphylaxis include a weak, rapid pulse, a skin rash accompanied by itching, nausea, vomiting, and diarrhea. Some triggers of anaphylaxis include certain foods, some medications, insect venom and latex.

Anaphylaxis requires a trip to the emergency department and an injection of epinephrine. If anaphylaxis is left untreated, it can lead to unconsciousness or even death.

Anaphylaxis symptoms include:
   •    Skin reactions; including hives with itching, flushed or pale skin (commonly present with anaphylaxis)
   •    A feeling of warmth
   •    The sensation of a lump in your throat and a swollen tongue or throat
   •    Constriction of the airways which can cause wheezing and trouble breathing
   •    A rapid and weak pulse
   •    Diarrhea, nausea, and vomiting
   •    Dizziness or fainting

If the person having an attack carries an epinephrine auto-injector (such as an EpiPen Jr or EpiPen), give her or him, a shot right away. Even if symptoms improve after an epinephrine injection, a visit to the emergency department is still necessary to be certain symptoms don't return.

Your immune system produces antibodies that defend against foreign substances; this is good when a foreign substance is harmful (such as certain bacteria or virus). However, some people's immune systems overreact to substances that shouldn't cause an allergic reaction. When this occurs, the immune system sets off a chemical chain reaction, leading to allergy symptoms. Normally, allergy symptoms aren't life-threatening. But some people have a severe allergic reaction that can lead to anaphylaxis. Even if you or your child has had only a mild anaphylactic reaction in the past, there's still a risk of more severe anaphylaxis. Depending on what you're allergic to, a number of allergens can trigger anaphylaxis.

Typical anaphylaxis triggers include:
   •    Certain medications, especially the penicillin family
   •    Foods, such as tree nuts (walnuts, pecans, almonds, cashews),
   •    Soy, wheat (in children), shellfish, fish, eggs and milk
   •    Insect stings from bees, wasps, hornets, yellow jackets and fire ants

The less common triggers include:
   •    Exercise
   •    Latex
   •    Medications used in anesthesia

Anaphylaxis symptoms also may be caused by other drugs — such as aspirin, ibuprofen, naproxen and the intravenous (IV) contrast used in some X-ray imaging tests. Although very similar to an allergy-induced anaphylaxis, this type of reaction isn't triggered by the allergy antibodies.

Anaphylaxis triggered by exercise is not common and varies from person to person. In some people, aerobic activity, such as jogging, triggers anaphylaxis. In others, less intense exercise, such as walking, can trigger a reaction. Eating certain foods before exercise or exercising when the weather is too hot, cold or humid has also been linked to anaphylaxis in some people.

Idiopathic anaphylaxis happens in few cases which are the cause of anaphylaxis never to be identified(4). Some things that may increase your risk include a personal history of anaphylaxis, a family history, and allergies or asthma.

A person that has allergies or asthma is at an increased danger of having anaphylaxis. Studies suggest that once someone has experienced a reaction, their chances of developing a more severe or acute reaction increases. If, a family member has had an exercise-induced reaction the risk of having this type of reaction becomes higher than it is for those without a family history.

There are treatments available for those who are affected by anaphylaxis. Many people who are at risk of anaphylaxis carry an auto-injector. This device is a combined syringe with a concealed needle that injects a single dose of medication when pressed against the thigh. Always be sure to replace epinephrine before its expiration date, using epinephrine that has expired could allow it to not work correctly.

First Responders, high risk individuals and their family members should know how to use the auto-injector. Additional life-saving steps such as cardiopulmonary resuscitation (CPR) may be necessary.

First Responders may administer any combination of the following medications including:
   •    Intravenous (IV) antihistamines and cortisone to reduce inflammation of your air passages and improve breathing
   •    Epinephrine (adrenaline) to reduce your body's allergic response
   •    Oxygen, to help compensate for restricted breathing
   •    A beta-agonist (such as albuterol) to relieve breathing symptoms

Having a potentially life-threatening reaction is frightening, whether it happens to your patient, those close to you or yourself. First Responders and people at risk should develop an anaphylaxis emergency action plan for their peace of mind.

   1.   CNN: Why are food allergies on the rise? - By Elizabeth Landau, CNN August 3, 2010 1:39 p.m. EDT. N.p., n.d. Web. 17 Mar. 2015.

       "Anaphylaxis Definition - Diseases and Conditions - Mayo Clinic." N.p., n.d. Web. 16 Mar. 2015.

   2.   MLA: " The Facts: Asthma & Allergies." Asthma & Allergy Center, N.p., n.d. Web. 17 Mar. 2015.

      MLA: "Allergy Statistics | AAAAI - The American Academy of Allergy ..."Allergy Asthma & Immunology. N.p., n.d. Web. 17 Mar. 2015.

   3.   Gupta, R, et al. The Prevalence, Severity and Distribution of Childhood Food Allergy in the United States. Pediatrics 2011; 10.1542/ped.2011-0204.

      World Health Organization. White Book on Allergy 2011-2012 Executive Summary. By Prof. Ruby Pawankar, MD, PhD, Prof. Giorgio Walkter Canonica, MD, Prof. Stephen T. Holgate, BSc, MD, DSc, FMed Sci and Prof. Richard F. Lockey, MD.

      Summary Health Statistics for U.S. Children: National Health Interview Survey, 2012, table 2.

   4.   MLA: "Anaphylaxis Definition - Diseases and Conditions - Mayo Clinic." By Mayo Clinic Staff. N.p., n.d. Web. 17 Mar. 2015.

   5.   Gut flora or, more appropriately, gut microbiota, consists of a complex community of microorganism species that live in the digestive tracts of animals and is the largest reservoir of microorganisms mutual to humans. In this context gut is synonymous with intestinal, and flora with microbiota and microflora. The gut microbiome refer to the genomes of the gut microbiota.

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