Why Do Mosquito Bites Swell & Itch?

Mosquito bites can ruin even the most anticipated summer holiday. One bite is persistently itchy and annoying, but several bites can be itchy enough to ruin any day. Most people will not react severely to a mosquito bite, but they will still swell and itch for several days.

Significance

• Female mosquitoes require certain nutrients from blood to survive. They have a needle-like nose called a proboscis which they use for collecting the blood of their victims. There are about 3,500 types of mosquito, and some of these species feed on the blood of humans.

Clotting

• An open wound clots easily. To avoid clotting as it feeds, the mosquito injects a little bit of saliva into the open wound as it penetrates the skin. This saliva contains chemicals known as anti-coagulants, that stop clotting for a short period of time.

Poison

• The chemicals in the mosquito saliva are left behind after the insect leaves. This causes a histamine response in our bodies, which is a slight allergic reaction. These allergens cause a raised red mark and itchiness after a couple of hours, which can last several days.