Itchy and swollen bump could be caused by insect bites or caterpilar. While bees and wasps inject venom when they sting, mosquitoes simply bite to feed on your blood. The swollen bumps and itchiness that follow come from an anticoagulant that the mosquito injects to prevent your blood from clotting, which triggers a mild allergic reaction that includes the typical round, red bumps.
For immediate relief, try antihistamine cream or stick. Maybe you bring your own cream/spray to reduce itchy and swollen bump. But, if it still not worked, you can try the asian/local herbs oil. Cajuput oil or insects oil or balm. It is very efective for itchy and swollen bump caused by local mosquito/insects bites.