Allergies & The Human Body

Blog Entry #1: How do allergies affect the body biologically and chemically?

            Food allergies are a popular topic today, especially as various communities, such as schools, make decisions about how to cope with the rise of allergies. The most common allergies are to peanuts, tree nuts, shellfish, milk, egg, wheat, soy or fish. Allergies can range in severity, but the most severe can cause anaphylaxis, a life threatening reaction. It is estimated that only 4-8% of children younger than 4 have true food allergies, but they do also diminish with age (Whitney and Rolfes). The biological and chemical reactions that occur in your body can be complex and confusing to some, so I hope to explain it clearly!

            Allergies occur because of a hypersensitive immune system, meaning that a body identifies something that is not harmful as toxic and attacks. An allergy is the body’s response to an antigen, which is a substance that causes the body to form antibodies as a reaction. Antibodies are produced by the immune system, the parts of the body that protect you from disease and anything toxic, in response to something the body does not recognize (“Antibody”). The immune system is able to recognize a foreign substance in an incredible way – each basic molecule, or group of cells, is different on the surface. Allergies come from a protein in food. Normally, a protein is broken down in the digestive tract into amino acids. When a food allergy occurs, it is because a protein is not broken down entirely into amino acids before being absorbed into the blood stream, and thus a large molecule is absorbed that is unrecognizable to the body. This triggers the immune system to respond and produce antibodies to attack the antigen (“How Allergies Work”).

            When someone comes into contact with an allergen after initial exposure, the body prepares itself so it can attack it if it comes around again. Very specific antibodies, called IgE, bind to surfaces of cells in order to protect it from the allergen. The cells that IgE binds to are special cells called mast cells that release a chemical called histamine. Once the allergen enters the body, the antibodies recognize the protein that is specific to the allergen and bind to it. This then alerts a group of proteins called the complement complex. In an allergic reaction however, the cells are attacked instead of the IgE antibody and are destroyed, releasing histamine. This chemical causes the blood vessels to expand and symptoms of the allergic reaction to begin (“How Allergies Work”). If you’ve ever taken Benadryl it is an antihistamine, which helps to counter the symptoms that the histamine causes.  

            Once an antigen enters the body, the immune system interacts with it immediately. However, symptoms may not show for up to 24 hours. Some symptoms that can occur include a skin rash, respiratory difficulties, vomiting, diarrhea, or anaphylactic shock (Whitney and Rolfes). Anaphylaxis is a severe reaction to an allergen. During anaphylactic shock, a person has difficulty breathing, which causes organs to become oxygen starved. It can cause death if not treated quickly. Currently the only effective treatment for anaphylaxis is an epinephrine injection, or an Epi-Pen as many people know it. Epinephrine is a hormone that is naturally produced by the body that constricts the blood vessels to open the airways.

Sources

Beach, Steve. "How Allergies Work."HowStuffWorks. N.p., n.d. Web. 1 Oct. 2014. <http://health.howstuffworks.com/diseases-conditions/allergies/allergy-basics/allergy3.htm>.

The Editors of Encyclopædia Britannica. "Antibody (biochemistry)." Encyclopedia Britannica Online. Encyclopedia Britannica, n.d. Web. 9 Oct. 2014. <http://www.britannica.com/EBchecked/topic/27783/antibody>.

Whitney, Eleanor Noss, and Sharon Rady Rolfes. "Life Cycle Nutrition."Understanding Nutrition. 13th ed. Belmont, CA: Cengage Learning, 2012. 513-514; 524-526. Print.

Blog #2: What treatments are available for allergies? How do they work?

            As of right now, there are very few treatment options for those who suffer from food allergies. One of the best options is to avoid the food or foods you are allergic to in the hopes of avoiding a reaction entirely. However, this can prove difficult when there is cross contamination of foods made in a processing plant or at an event where not all ingredients are listed. This becomes more of a problem depending on how severely allergic someone is as well. In situations when a reaction does occur, there are two treatment options based on how severe the reaction is – antihistamines or an epinephrine injection. Antihistamines are used for mild symptoms, while epinephrine injections are used for the life threatening symptoms of anaphylactic shock (“Treatment and Managing Reactions”).

            Antihistamines, such as Benadryl or Zyrtec, respond to the histamines that are released when a mast cell is attacked by an allergen (“Antihistamines for Allergies”). Antihistamines block histamines by coating receptors, a part of cell walls that allow molecules from outside the cell to bind to the cell (Hasselbring). Antihistamines block the histamines from binding to the cell receptors, preventing symptoms of inflammation, such as a runny nose or hives, from occurring. Antihistamines are used in cases of mild, non-life threatening symptoms and can be purchased without a prescription. They are also often used for allergies to the environment, such as pollen, during the spring allergy season.

Epinephrine injections (such as Epi-Pen, Twinject or Auvi-Q) are used for allergic reactions that cause anaphylaxis, which is life threatening. Anaphylaxis causes the body to struggle to pump blood throughout the body, depriving the body and organs of oxygen, as well as causing the airways to tighten and difficulty breathing. Recall that epinephrine, a type of adrenaline, is a hormone produced naturally by the adrenal glands, which are located on top of the kidneys. Epinephrine causes the blood vessels to tighten, which in turn increases pressure in the blood vessels and allows blood to be pumped more efficiently, and relaxes the airway muscles (“Epinephrine”). Blood then is able to flow throughout the body, bringing oxygen to the necessary organs and allowing a person to breathe easier. In the case of an allergic reaction that is severe enough to cause anaphylaxis, an injection of epinephrine must be used in order to counteract symptoms. Although the body does make some epinephrine naturally, it does not make enough to save a persons life during anaphylaxis.  

Epinephrine injections are autoinjectors with a concealed needle and syringe that carry a single dose of epinephrine. When pressed against the thigh and the device is triggered, the medication is injected. They are designed to be easy to use for life threatening circumstances (“Epinephrine Injection”). People who suffer from severe food allergies should always carry an autoinjector with them and be trained on how to use them. It is also important to check the expiration date periodically and replace the injector as needed, in order to ensure that the epinephrine will be effective when you most need it. Furthermore, friends and family members should be educated on how to work the injector so that if you are ever unable to use your autoinjector, someone else can.    

           

For those trying to avoid food allergies, here is a recipe that has none of the most common food allergens (peanuts, tree nuts, soy, egg, wheat, milk, shellfish, or fish). This recipe is from foodallergymama.com, a site with great recipes for those with food allergies!

Granola

½ cup sunflower butter or other nut butter alternative

½ cup honey

2 tablespoons vegetable canola oil

1 teaspoon vanilla extract

1 teaspoon ground cinnamon

3 cups old fashioned rolled oats

1 teaspoon salt

2 cups dried fruit of your choice

Pre-heat oven to 300 degrees and line a baking sheet with parchment paper.

In a medium saucepan, combine nut butter alternative, honey, oil, vanilla, and cinnamon over low heat until the mixture is smooth.

In a medium bowl combine the oats and salt. Add the butter mixture to the oats. Stir well.

Spread the granola mixture onto the pan and bake for 15-20 minutes, until the granola is lightly browned and toasted. Remove from oven, let cool on baking sheet, and add dried fruit.

Sources

Rudnicki, Kelly. "Category Archives: Recipes." Food Allergy Mama. 8 July 2013. Web. 16 Nov. 2014. <http://www.foodallergymama.com/category/recipes/>.

"Treatment & Managing Reactions - Food Allergy Research & Education." Food Allergy Research & Education. 1 Jan. 2014. Web. 1 Nov. 2014. <http://www.foodallergy.org/treating-an-allergic-reaction>.

Hasselbring, Bobbie. "How Do Antihistamines Work?" HowStuffWorks. 1 Jan. 2014. Web. 15 Nov. 2014. <http://health.howstuffworks.com/diseases-conditions/allergies/allergy-treatments/how-do-antihistamines-work.htm>.

"Antihistamines for Allergies: Types and Side Effects." WebMD. WebMD, 1 Jan. 2014. Web. 15 Nov. 2014. <http://www.webmd.com/allergies/guide/antihistamines-for-allergies>.

"Epinephrine Injection: MedlinePlus Drug Information." U.S National Library of Medicine. U.S. National Library of Medicine, 15 Dec. 2012. Web. 15 Nov. 2014. <http://www.nlm.nih.gov/medlineplus/druginfo/meds/a603002.html>.

"Epinephrine." Epinephrine. Web. 16 Nov. 2014. <http://www.udel.edu/chem/C465/senior/fall00/Performance1/epinephrine.htm.html>.

"Food Allergy." Mayo Clinic. 12 Feb. 2014. Web. 15 Nov. 2014. <http://www.mayoclinic.org/diseases-conditions/food-allergy/basics/treatment/con-20019293>.

"Antihistamines - How They Work." NHS Choices. 1 Jan. 2013. Web. 16 Nov. 2014. <http://www.nhs.uk/Conditions/Antihistamines/Pages/How-does-it-work.aspx>.

Blog Post #3 – What treatment options are being researched? How might these treatment options affect people who suffer from food allergies?

            As the rate of food allergies has increased along with severity, there has been a growing effort to develop new treatments that will allow people to live without fear of having a severe allergic reaction. Two of the most promising treatments are anti-IgE therapy (the drug is called omalizumab) and oral immunotherapy. There is some research that shows that administering the anti-IgE therapy first will help make oral immunotherapy safer and faster. Both of these substances need to require multiple doses for the potential maximum benefits.

            Recall that IgE is a type of antibody that binds to the surfaces of cells in order to protect the cells from the allergen. IgE binds to mast cells, which are immune system cells that release histamine. During an allergic reaction, the allergen attacks the mast cells rather than the IgE antibody, triggering histamine to be released. In anti-IgE therapy, the medication omalizumab interferes with the body’s ability to use the antibody IgE. By preventing the body from using IgE, the body will not react to the allergen negatively and will not produce histamine, stopping an allergic reaction (“Future Therapies for Food Allergy”). There have been some studies that have shown the effectiveness of this technique, however, there is some concern that omalizumab may cause anaphylaxis, the very symptom it is trying to prevent (“Food allergy: Treatments and drugs”). Anti-IgE therapy is currently approved for treatment of asthma caused by allergies, giving researchers hope that it could be just as effective for food allergies.

            Oral immunotherapy is a controlled administration of small doses of the food a person is allergic to. The food is placed under the tongue or swallowed. It starts with a very small dose of the food and over time increasing doses are given to the person (Iyengar et. al). The goal is to desensitize the person to the food at first, with the final goal being to build a tolerance to the allergen. When a person is given oral immunotherapy, they are given a powder substance of the food allergen in a controlled setting such as a hospital or doctor’s office (“Advancing a Cure”).

            It recently has been suggested that anti-IgE therapy be administered before oral immunotherapy, in order to help a personal tolerate the oral immunotherapy better, faster, and without a severe reaction such as anaphylaxis. Some studies have proven that this is effective and that anti-IgE does in fact minimize the reactions to oral immunotherapy and makes desensitization more rapid (Gever). Neither of these treatments have been approved by the FDA yet and additional testing is still needed.

            These two treatments offer not only health benefits to individuals who suffer from food allergies, but also social benefits. If a person does not have to live in fear of a reaction, their quality of life will be improved. Those who suffer from food allergies will be more comfortable in social situations that involve food and will not have to worry about being stigmatized for their food allergy. It has been suggested that children who suffer from food allergies have higher rates of anxiety, depression, and eating disorders (Chugh). Treatment and prevention of allergic reactions would prevent further mental health and physical conditions. Additionally, these treatments could possibly save hundreds of lives and prevent deaths that occur from allergic reactions. It is important that these treatments are funded and more research is done so that people are able to live healthy, fulfilling lives.

Sources

"Food Allergy: Treatments and Drugs." Mayo Clinic. 12 Feb. 2014. Web. 15 Nov. 2014. <http://www.mayoclinic.org/diseases-conditions/food-allergy/basics/treatment/con-20019293>.

"About Allergies / Future Therapies for Food Allergy." UCLA Health. 1 Jan. 2010. Web. 15 Nov. 2014. <http://fooddrugallergy.ucla.edu/body.cfm?id=42>.

Iyengar, S., RH DeKruyff, DT Umetsu, and KC Nadeau. "Oral Immunotherapy and Anti-IgE Antibody-adjunctive Treatment for Food Allergy." National Center for Biotechnology Information. U.S. National Library of Medicine, 1 Jan. 2012. Web. 15 Nov. 2014. <http://www.ncbi.nlm.nih.gov/pubmed/22244236>.

Gever, John. "Anti-IgE Drug Speeds Up Allergy Therapy." Medpage Today. 7 Mar. 2012. Web. 18 Nov. 2014. <http://www.medpagetoday.com/MeetingCoverage/AAAAI/31534>.

"Advancing a Cure." FARE Research Overview - Food Allergy Research & Education. 1 Jan. 2014. Web. 18 Nov. 2014. <http://www.foodallergy.org/research/overview>.

Chugh, Priyanka. "The Social Impact of Food Allergies." The Huffington Post. TheHuffingtonPost.com, 23 Dec. 2013. Web. 18 Nov. 2014. <http://www.huffingtonpost.com/priyanka-chugh/living-with-food-allergies_b_4480918.html>.