Why Does Itching a Mosquito Bite Make It Worse?

Nathan asks: Why does itching a mosquito bite make it itch more?

Now You KnowIt all comes down to your body’s histamine response to the female mosquito’s saliva.  After the mosquito has drunk her fill of your blood, she leaves behind the cocktail that is her saliva.  Your body’s response to this foreign substance is to produce a variety of antibodies to bind to the antigens in the saliva, which in turn releases the nitrogen compound histamine.

Why this is a good thing most of the time is that histamine helps your white blood cells and other proteins engage whatever is invading your body by making the capillaries of these cells more permeable.  The downside in the case of mosquito bites is that this triggers an inflammatory response causing the bite region to swell into a nice pink bump.

So why does scratching the mosquito bite make it worse?  Because this irritates and inflames the area even more, resulting in your immune system kicking into overdrive to try to get rid of the foreign substance.  So this means more inflammation for you, resulting in an ever swelling, itchy bump that just won’t go away.

So bottom line, while itching a mosquito bite will give temporary relief, it will only result in an even itchier and larger bump that will stick around longer than it would have had you not itched.  So don’t itch!

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  • You mean “Why does __scratching__ a mosquito bite…”

    • Daven Hiskey

      @Keith: True that would have been a better word choice. However, many dictionaries do allow “itching” to be used as a transitive verb, synonymous with “scratching”; so in these cases, you can itch and itch, though purists would likely look down upon it. 😉

  • Any dictionary that says scratching and itching mean the same thing should be burned immediately. You scratch an itch. You don’t itch a scratch.

    • Daven Hiskey

      @Len: Dictionaries reflect common usage of words. If the common usage changes, so will the dictionary’s definition. Language isn’t static.

  • Piers "Morgan" Moron

    Bollocks Daven. You’re wrong and you know it.

    • You can’t call that a debate at this time.
      It looks like they may have removed some responses by the statement after the comments:

      protected by tchrist Jul 21 ’14 at 23:31

      Thank you for your interest in this question. Because it has attracted low-quality answers, posting an answer now requires 10 reputation on this site.

      Meanwhile the author of this article should correct the title. It is cute when young children use this as a transitive verb, only because they don’t know better. They should still be corrected as they become capable of comprehension before they get stuck using it this way.

      This usage to me says he should have been corrected at a younger age. I can’t help getting a bad first impression. I threw up in my mouth a little. 😉
      I wonder if he uses “irregardless” as well. Technically a word, but not the accepted preferred word for regardless.

      I have a good friend who interchanges “brought” and “bought”.
      She is aware she does it, but won’t work on breaking the habit. I know that is unrelated, but that is where this took my thoughts. As well as people who use “axe” for “ask”, “nucular” for “nuclear”, “flustrated” for “frustrated”. Just generally uneducated or highly peer/urban influenced.

      I am not a master of the language, but this is sad, and lacks class imo.

  • Moving away from the grammar police: does scratching/itching the bite site cause a significant increase risk of infection? More urban-myth-ish: why does pressing an “X” over the bite with your fingernail seem to help?

    • It’s literally as bad as getting “swim” and “cold” mixed up. You wouldn’t not care about using one instead of the other because it completely changes the meaning/sense of a sentence, which is why I find it baffling that you still continue to use “itching the bite”. It just makes you look very stupid…

  • On topic, I wonder why it is called a bite, when it’s really more like a sting or stab? We all need to be corrected! lol

    They probably didn’t examine the behavior up close in the early days, and assumed it was a bite by the feel of the severe itch. They are so stealthy, that they’re usually done before you notice them. Hence the mystery, when seconds later you notice the itch.
    Once in a while you get lucky and fell them land or move their legs on your skin or during the deed. giving you a chance to avoid or mitigate the severity of the “bite” by smashing them.

  • If the itching and swelling is caused initially by mosquito saliva, would washing the area immediately after a bite or sting reduce the histamine reaction?
    BTW, I am on board with the grammar criticism. One scratches an itch but does not itch a scratch. To say otherwise is simply poor grammar, whatever popular and uneducated usage might be.

  • My native language is not even English and I immediately thought:

    “Isn’t the correct word ‘Scratching’?!”.

    I even went to Google Translate to make sure.

    So, yes, Mr. Hiskey, take responsibility for your mistake.

    This is the correct, again, way to go.

    Otherwise, some of us here, that were taught English after our first native language, are at risk of forgetting the proper English we learned… not good, that.

    @Len and @ Pierce “Morgan” Moron, I agree with both your comments. Nice!

  • It’s not a mistake:

    “2. To scratch (an itch).”

    “Informal. to scratch a part that itches.”

    Language evolves with the people who use it. If you know what he meant when he says “itching” then the word did its job in conveying the message to you.

  • But damn does it feel good in the moment…

  • Cheryll Hinman-Bickham

    I never heard the reversal of itch and scratch until I moved to Ohio; yet, I was always told that Ohio was an extremely educated state. After 27 years here, I am convinced that language skills are more advanced in the deep south!

  • ghrammer puleece

    I’ll itch an itch any day! I’m with you David! Fight the resistance!

  • Thank you for having proven that Yanks in general are so stupid that they cannot even speak their own mother tongue properly. English there is devolving rather than evolving. Truth be told, there is certainly a difference between simplifying and dumbifying words. Ah well, leastwise evermore will such people make me feel superior.

    • Haha holy shit your comment is perfect /r/iamverysmart material. You might see yourself back on reddit soon.