• Question: why are some people allergic to things?

    Asked by mwilliams to Julia, Drew, Amy, Kimberley, Sara on 21 Jun 2011. This question was also asked by daidai, melissamartin123, mvenkataraman.
    • Photo: Drew Rae

      Drew Rae answered on 17 Jun 2011:

      Hi Mwilliams. Allergies are our bodies immune system over-reacting to things. We aren’t entirely sure what causes them. There’s definitely both genetic and environment components – growing up in an environment that is sterile or having health problems whilst very young can both influence having allergies.

    • Photo: Sara Imari Walker

      Sara Imari Walker answered on 19 Jun 2011:

      Hello mwilliams, daidai, and melissa! Our bodies immune system works by identifying and killing pathogens. However, for some people this immune response malfunctions and starts identifying harmless things (like pollen) as pathogens! We don’t know exactly why this happens. I know I wish I didn’t have allergies!!

    • Photo: Julia Griffen

      Julia Griffen answered on 19 Jun 2011:

      These guys have it 🙂

    • Photo: Amy MacQueen

      Amy MacQueen answered on 21 Jun 2011:

      Hey guys!

      That is actually a very good question and no one really knows the answer! An allergy is when your immune system (which is designed to protect you against harmful pathogens) over-reacts at things that are generally harmless and causes your body to mount an allergic response. This can be very uncomfortable!! Allergic responses involve a sort of T cell in your body called the Th2 cell and they also involve release of a chemical called histamine by cells called mast cells. This is why antihistamines help you when you have an allergy because they actually look enough like histamine that they can bind to things the histamine binds to and stop the histamine getting in to cause a rash etc!!

      But why do some people have allergies? There is something called the “hygeine hypothesis” which goes along the lines of that the cleaner an environment you have as a child the more likely you are to develop allergies as you have not become “tolerant” to bugs as a baby/toddler because you haven’t seen them. Apparently if you have a pet (or an older brother!) as a baby you are less likely to develop allergies – because they both carry dirt! 🙂
      People think this because allergies are more common in Western cultures where we have become obsessed with cleanliness and anti-bacterial sprays, processed foods etc – but this is unlikely to be the whole story as sometimes your genes pre-dispose you towards allergies. Some people are naturally more “atopic” which means they are more likely to develop allergy!

      Sometimes your body can get confused – people who are allergic to latex gloves are often allergic to bananas as well because they contain similar proteins! This is called allergy “cross reactivity”.

      Hope this was helpful guys, any more questions just give me a shout! 🙂