Allergies For Dummies

My name is Arisha Afzal and this is just another blog on healthy living!

[healthymaniacs]

Allergies for Dummies: Type 1 Hypersensitivity

Ever wondered what it feels like to have an allergic reaction? Trust me, you don’t want to know! Whether you have allergies yourself or know someone who does, everyone knows that allergies can be a huge pain in the neck. Itchy redness and swelling? No, thank you! However, as much as we all hate having to deal with those annoying symptoms, many of us actually don’t have the slightest clue on what allergies actually are or why we might be allergic to something in the first place. I happen to be allergic to dust and mold- which makes a great excuse to escape cleaning responsibilities- yet in all the years of dealing with this problem, I have realized that the knowledge I received my local doctors are severely limited to just some basic treatments to temporarily eliminate the symptoms. Today’s post will be discussing the actual background of allergies and why we even get them in the first place! Defense is the best offense! And if you don’t think the realm of immunobiology is flat out war, you’d be very mistaken.  (Here comes the fun part, Science Time! Get ready nerds and sharpen your knowledge knives!)

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[healthymaniacs]

What are Allergies Really all About?

SHOWDOWN Time!

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What does it even mean to be “allergic?” Turns out that the same biological system that is there to protect us against dangerous organisms, can actually harm us in some ways. The immune system functions to protect the human body against pathogens (viruses, bacteria and even cancer) by recognizing dangerous molecules in the body and getting rid of them to maintain a constant and safe environment [1]. Our immune system is always on high alert, yet sometimes it can also go overboard. Allergies are typically an overreaction or “hypersensitive” response to a relatively harmless substance, where our immune cells initiate a full blown attack when in contact with the “allergen” [1] . Imagine using a machine gun to shoot down a fly. Yeah, bad, bad idea. 

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[healthymaniacs]

Antibodies and Recognizing Danger

Our immune system has developed a way to recognize and differentiate between cells: our own cells are known as “self” and molecules that come from outside our bodies, known as “non-self” [2] . If a non-self substance is recognized to pose a threat to your health, it is eliminated immediately. Our immune system does this by using “antibodies,'' special molecules on the surface of our immune cells which act like scanners that can recognize specific molecules, or “antigens” on the surface of the foreign substance [2] . You know how when you’re trying to hide something and your parents can give one sniff and instantly expose your lies? It’s like that, but here, the story won’t end with you just getting grounded!

Since our antibodies are designed to recognize specific antigens, they act like a signal for immune cells to attack [3]. War cry intensifies in the background. People with allergies have an abundance of a particular kind of antibody known as “IgE” which recognizes antigens on harmless substances like peanuts or pollen [3] . The amount of IgE you have is usually dependent on the genes you receive from your parents (Gee, thanks Mom and Dad┌( ಠ_ಠ)┘) so particular allergies are usually common in the family [3] .

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[healthymaniacs]

Immune Response: How it all Goes Down!

You probably won’t ever know you are allergic to something unless you come into contact with the particular substance you are allergic to. But ignorance isn’t always bliss. When the immune system is first exposed to the “allergen,” they are randomly taken up by special immune cells known as dendritic cells which basically take parts of the allergen and present it to other immune cells, known as T-cells [2]. Now, in normal people, the T-cell wouldn’t even look twice at the allergen before going about it’s happy way. However, people with food allergies are different; they have T cells that not only recognize the harmless allergens as dangerous but also spread this news to the other white blood cells [4] ! 

Here’s where our good old friend IgE comes in. The activation of T-cells results in the production of IgE antibodies that recognize the allergen and are passed along and picked up by other immune cells and used to identify more allergens [3] . Now that the immune cells are equipped with IgE antibodies, they are able to recognize the allergen at any time and initiate an attack immediately [3] . This is why any allergic reaction after the first contact is always rapid and much higher in magnitude [6] . Once an allergen is recognized by the IgE antibody, the rest is history. We all know how it progresses from there with the intense itchiness, sneezing, redness and swelling. For some people the reaction may even become severe and life threatening.

Fun Fact: People with allergies may even have different expression of T-cell genes from birth compared to people without IgE allergies [5] ! So allergies really are related to the genes you get from your parents and less influenced by external factors like some people may think. (My mom often told me I became allergic to dust because I played with too much dirt as a child, but I guess we can now conclude that to be complete hearsay). 

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To think that all this time these allergic reactions were really just our bodies being overprotective may come as a comfort to some, but learning the biological basis for allergies can also be an eye-opener. Next time I get a reaction after cleaning my dusty room, I’ll be sure not to blame the poor dust molecules, but my own immune cells instead!

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[healthymaniacs]

Allergies: Myth vs. Facts

MYTH #1: "Colds and Allergies are exactly the same! You can't even tell them apart!" 

MYTH-BUSTER: Nuh uh! They may feel similar at times (and show similar symptoms such as runny nose and sneezing), but they belong to different cliques in the School of Immunology. Although a normal cold is the result of actual viruses attacking your immune system, allergies are just the overprotective response of Mother Immune System to poor old allergens [7] . Here's a tip: itchy eyes are a sign of allergies, not usually a cold [7] !

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MYTH #2: "Allergies can't be treated! Just avoid the trigger!" 

MYTH BUSTER: Well, duh, you should try to avoid exposing yourselves to triggers of an allergy you are prone to. But that's just the bare minimum! Why not also try allergy shots? Meet my good old friend, Mr. Immunotherapy; your body is exposed to tiny doses of the allergen at a time and eventually your immune system's sensitivity to the allergen lessen [8] ! It's like when you eat something bitter enough, after a while you barely notice the taste! Of course, you can try common treatments from your local drugstore like nasal sprays and decongestants, as well!

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MYTH #3: "Take that Medicine After You Show Symptoms!" 

MYTH BUSTER: If the weather forecast tells you that a hurricane is coming, you don't wait for the storm to knock on your door before you start preparing for refuge! Same rationale here! If you start taking medicine a few weeks before the season of allergy begins, the drugs (cell stabilizers) actually block certain immune cells, called mast cells, from launching an attack and releasing the chemicals that cause allergic reactions in places like the eyes or nose, so you're free from itchy eyes and runny nose [9] ! Interestingly though, seasons may play a bigger role that just triggering allergies. Recent research suggests there may even be a link between fall births and the potential of developing allergies [10] . Crazy right?  

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[healthymaniacs]

Histamine: Friend or Enemy?

Ever wonder what Allergies were made of? In this video, you become introduced to your good friend ...or ...enemy!? Histamine is usually a good worker, acting as a signaling molecule that delivers messages to cells throughout the body and works with the immune system [11] . But when it involves He Who Must Not Be Named (whispers: allergens!), histamine, causes a massive overreaction that proves harmful to the body [11] . Ultimately, is histamine good or bad? Watch the video to make your decision!

[healthymaniacs]

References/Work Cited

[1] Peden, D., Reed, C.E., et al.  (2010) Environmental and occupational allergies. Journal of Allergy and Clinical Immunology, 125 (2), 150 - 160.

[2] Yu, W., Freeland, D., & Nadeau, K. C. (2016). Food allergy: immune mechanisms, diagnosis and immunotherapy. Nature reviews. Immunology, 16 (12), 751–765.

[3] Gould, H.J., & Sutton, B.J. (2008). IgE in allergy and asthma today. Nature Reviews Immunology, 8, 205-217.

[4] Ueno-Yamanouchi, A., Khan, F.M., Serushago, B. et al. (2011). Allergen-specific T cell quantity in blood is higher in allergic compared to nonallergic individuals. Allergy, Asthma & Clinical Immunology, 7(6). 

[5] Martino, D.J., Bosco, A., McKenna, K.L., Hollams, E., Mok, D., Holt, P.G., Prescott, S.L. (2012) T‐cell activation genes differentially expressed at birth in CD4+ T‐cells from children who develop IgE food allergy. Allergy, 67 (2), 191–200.

[6] Lass, C., Merfort, I., & Martin, S.F. (2010). In vitro and in vivo analysis of pro- and anti-inflammatory effects of weak and strong contact allergens. Experimental dermatology, 19 (11), 1007-13 .

[7]Cold, Flu, or Allergy? (2019, May 28). Retrieved from https://newsinhealth.nih.gov/2014/10/cold-flu-or-allergy.

[8] James, C., & Bernstein, D. I. (2017). Allergen immunotherapy: an updated review of safety. Current opinion in allergy and clinical immunology, 17(1), 55–59. 

[9] Finn, D. F., & Walsh, J. J. (2013). Twenty-first century mast cell stabilizers. British journal of pharmacology, 170(1), 23–37. 

[10] Keet, C. A., Matsui, E. C., Savage, J. H., Neuman-Sunshine, D. L., Skripak, J., Peng, R. D., & Wood, R. A. (2012). Potential mechanisms for the association between fall birth and food allergy. Allergy, 67 (6), 775–782.

[11] Xie, H., & He, S. H. (2005). Roles of histamine and its receptors in allergic and inflammatory bowel diseases. World journal of gastroenterology, 11 (19), 2851–2857.

Images:

[1] Oprah Winfrey Putting on Sunglasses Gif. (n.d.). Retrieved from https://giphy.com/posts/lets-celebrate-oprahs-birthday-in-gifs

[2] Dis Gon B Gud Gif. (n.d.). Retrieved from https://giphy.com/gifs/facebook-family-step-8PMiEdVbzMN4Q

[3] Immune System Y U No Work Meme. (n.d.). Retrieved from https://makeameme.org/meme/immune-system-y

[4] The gray suit of Michael Bryce in Hit­man & Body­guard. (2017). Retrieved from https://www.spotern.com/en/spot/movie/the-hitman-s-bodyguard/78864/the-gray-suit-of-michael-bryce-ryan-reynolds-in-hitman-bodyguard

[5] Man holding Id card. (n.d.). Retrieved from https://www.greenkingsdc.com/

[6] The Hitman's Bodyguard holding guns. (n.d.). Retrieved from http://www.imfdb.org/wiki/Hitman's_Bodyguard,_The

[7] Successful businessman passing a black briefcase to his partner near office building. (n.d.). Retrieved from https://dissolve.com/video/Successful-businessman-passing-black-briefcase-partner-royalty-free-stock-video-footage/001-D1878-23-005

[8] Spongebob and that's how the immune system works meme. (n.d.). Retrieved from http://www.quickmeme.com/p/3vppdy

[9] Will Smith Hives Allergy Reaction Gif. (n.d.). Retrieved from https://giphy.com/gifs/reaction-E2i9ILCmSJUkg

[10] Cartoon Immune Cells Attack Bacteria. (2019). Retrieved from https://gfycat.com/ko/misguidedsecondaryirishwaterspaniel-immune-system-phagocytes

[11] Homer Simpson You're All Nuts Gif. (n.d.). Retrieved from https://giphy.com/gifs/beer-allergy-cashews-kgEzg8u7riCUo

Avatar:

Heart And Fork Sign Healthy Food Icon Vector. (2019). Retrieved from http://www.shopatcloth.com/2018/6/heart-and-fork-sign-healthy-food-icon-vector_studiogrfx.com/

Background:

Thin line art street food seamless pattern vector image. (n.d.). Retrieved from https://www.vectorstock.com/royalty-free-vector/thin-line-art-street-food-seamless-pattern-vector-22488477

Video:

U.S. National Library of Medicine. (2017, September 8). Histamine: The Stuff Allergies are Made of [Video file]. Retrieved from https://www.youtube.com/watch?v=1YrKVobZnNg&feature=emb_title