when mosquito bite you why do they itch afterwards?

Question

if they are only sucking blood from you then how come they itch afterwards?

Answer 1

When the mosquito bites, their proboscis (the straw-like feeding device) penetrates the skin up to the subcutaneous layer of the skin beneath the dermis. When this happens, an inflammation occurs. The basophilic and mast cells (type of white blood cell) is stimulated to release histamine which contracts the smooth muscles. Since WBC uses glucose as source of energy, lactic acid is produced from glucose. Lactic acid plus the contraction of the smooth muscles plus interleukin produced by WBC gives you the itchiness. The increased flow of blood in the area causes redness and increase plasma concentration causes swelling.

Answer 2

Male Mosquito's Feed On Nector And Various Plant Juices,

You'll Find Its The Female Mosquito That Feeds On The Blood Of Birds, Reptiles, Animals and Other Mammals,
This Is Due To Her Requiring The Protien From The (Above) Blood To Provide For Her Eggs.....

The Sting / Bite Is Injected By A Fine Neddle Made Up Of Trillions Of Sub Atomic Paticles, Anyway, She Injects Histamine in Her Saliva Which Causes A Reaction, And Hence Its The Same Effect Pollon Has On Hayfever Suffers,
Itching, Swelling, Red etc.....

These Are Effective To Treat The Bites -
Oral Antihistamines
Cold packs
Calamine lotion

Be Careful As Some Inject Eggs If They Are In Season...

Answer 3

Could be for a couple of different reasons
1. Could be because they've been near infected or stagnant water (mozzies love watery places) and they've introduced some infection into the site when they inserted their proboscis to bite you.
2. Whether they have infection on them or not, their bite sets off a 'histamine' response in your system, just as nettles and other stuff do. This means your body is sending loads of histamine out to attack the foreigner that it's just been invaded by and it's this stuff that itches. By taking or applying an 'anti-histamine' you cool this response and reduce the itch. Scratching is the biggest NO NO as all this does is spreads the histamine response to adjoining body cells and increases the amount of itch - so FINGERS OFF.

Answer 4

This old one eh? It is a little known fact that when a mosquito bites you hundreds of tiny lifeforms make a break for freedom. The true origins of these blighters are not yet known but they are thought to be captured and saved as a kind of "living packed lunch" whilst the mosquitos are in space searching for signs of life not yet known to man(or mosquito). Mosquitos are fiercly competitive and have been competing with man in the space race ever since they found out about it. Having wings means that they have a distinct advantage over us and it is thought that they have visited places which man has not yet dreamed of.

Answer 5

As they bite you, they inject an anticoagulant into your blood so it doesn't start to clot and clog up its little snout. the substance they inject, though only a tiny amount, is an irritant so causes itching and redness. Some people are quite seriously allergic to it. the more you scratch it, the more the stuff spreads around the bite.

Answer 6

The clever little things inject something into the bite before they start to feast which is effectively a local anaesthetic - to prevent the person being bitten from feeling anything. As the anaesthetic wears off it begins to itch

Answer 7

I think that is something to do with the solution they inject into you. I've heard that they inject a coagulant (spelling might be wrong and i might be wrong with the stuff they inject) and this makes the blood more watery and easier for the mosquito to suck out. Once its had its fill you still have coagulant stuff inside and i think this is what makes it itch.

Answer 8

When the mosquito inserts its proboscis into your capilleries, it injects its saliva which contains a substance that prevents blood clotting. This allows it to draw the blood up its proboscis easily. The substance will cause irritation as well as preventing blood clotting, leaving a red "bite" mark.

Answer 9

they itch as the mosquito has injected an enzime to help the blood flow while it's sucking your blood. It's the enzime which causes the itch.

Answer 10

Because you have an allergic reaction to them. The foreign invasion causes the release of histamines which make your itch. You can treat it best either with an antihistamine cream (such as diphenhydramine) or hydrocorisone cream.