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Why do mosquito bites itch
Sometimes it is the smallest things that can inflict the greatest pain. Case in point: a mosquito bite! The moment one of these nasty insects bite you, your body automatically kicks in its defense mechanism to block the area from infection. Maybe that would explain the red bump and pain you experience immediately after a mosquito bite. And that would be the part that is easy to handle.
What is hard to handle is the incessant itching you develop in the area after a mosquito bite? What exactly causes this itching and why is your body not able to control it the same way it controls the pain that occurs after a bite? To understand that, we would need to dive into the details of what exactly happens when a mosquito bites us!
For starters, did you know that only the female mosquitoes bite in order to feed? And did you know that they actually don’t bite you at all? All they do is insert their needle like mouths called proboscis under your skin. And that is what causes the sting that you feel.
After inserting the proboscis into your skin, a female mosquito would search for a blood vessel. When she locates one, she uses the proboscis to suck out the blood from the vessel. While doing so, she would release some of her own saliva into the vessel. The saliva would act as an anticoagulant and prevent the blood in the vessel from clotting, thereby making it easier for her to feed on the flowing blood.
By this time around, your body’s immune system would realize that a foreign substance, aka the mosquito’s saliva has entered the blood stream. In order to prevent the saliva from spreading, your body would create a substance called histamines to block it.
These histamines would quickly approach the site where the mosquito is feeding and cause the blood vessels to swell up. This would lead to the appearance of a small reddish bump (also called a ‘wheal’) on the exact spot where the mosquito bit you.
The sudden inflammation of the blood vessels causes irritation in the nerves in this area. And it is this irritation that causes the itching sensation that you feel immediately after a mosquito feeds on your blood.