goodtoknow says: Insect stings, wasp stings and bites can be very painful but aren't usually serious unless you or your child develop a severe allergic reaction, which is rare. Stings burn and are usually caused by wasps, bees and hornets. If the area swells don't panic. You may have an allergic reaction, but it isn't serious unless the swelling affects other parts of your body, particularly your face and throat. If this happens, call an ambulance or get down to A & E immediately. Otherwise treat it by scraping out the sting as quickly as possible, then soothe it with a cold flannel and take antihistamine tablets.
For a full medical explanation of the causes, symptoms and treatments of insect stings and bites from patient.co.uk, read on.
If you are stung by a wasp, bee, hornet, etc, then scrape out the sting as quickly as possible. Do not pluck it out as this may squeeze more venom into the skin. In most cases the sting causes pain and slight swelling, but has little other effect. Some people are allergic to stings and can develop reactions that can be life-threatening. Call an ambulance immediately if you suspect an allergic reaction soon after being stung. Insect bites (not stings) rarely cause serious allergic reactions but can cause small itchy lumps to appear on the skin. Itch may be eased by a soothing ointment, antihistamine tablets, or steroid cream. Some insects infest pets, furniture, etc, and can cause repeated bites.