Why does it itch so bleak when a masquito bites?

Why does it itch so bleak when a masquito bites?
When a mosquito bites you (it's actually a puncture, not a bite), it first injects a moment or two bit of saliva that contains a chemical that prohibits blood clotting so it can drink without problems. This chemical is a skin irritant to most nation and causes a terrifically localized histamine reaction, resulting within swelling, redness and itchiness.
When a mosquito bites, it injects saliva to facilitate the blood clot in you afterwards sucks blood out. The saliva is a poison to your body, so when white blood cells show up to stop the invading poison it results contained by the itchy feeling.
That's my best most erudite guess. But I know the saliva being injected member is right lol