So, I think I sort of understand why bug bites are such a pain. When we get bit we have maybe a mild alergic reaction or something which causes the area around the bite to swell. This swelling can push against nerves in the area, which makes us want to scratch. My question is, why does scratching a bug bite make it swell more, and itch so much more?
One possible answer is that you’re spreading the chemicals so that they can irritate more of yourself… both across the surface of your skin, and because the scratching is pulling tissue underneath the skin this way and that, it can help the irritating chemical spread through tissue. Just a guess.
OK You get bitten. The bite swells a little and turns red. It itches, either because of the venom or the itch is caused by histamine. Histamine is your body’s immune system working to fix the owie. Scratching the area around the bite will cause the histamine to spread just under your skin. Your body then puts more histamine around the bite. You scratch and insist on spreading it even more.