Just rub some salt on till that all the grains are gone.
For people who go to countries where there are a lot of mosquitoes. A good remedy is vitamin B so you do not get stung. Beginning even before you leave.
Take an aspirin and lick it briefly. Now rub vigorously by aspirin over the hump and the burden is gone!
Rub with ordinary cooking vinegar itching is right away!
Against itchy mosquito bite: toothpaste