About Insect Stings: Symptoms and Complications
Bee and wasp stings are immediately obvious. A sharp pain is followed by a burning sensation that soon resolves into a major itch. A red ring or bump appears at the site of the wound. The important thing to remember is that bees' stingers are barbed and usually remain in the wound. In its haste to get away, the bee literally tears the stinger and the attached poison sac out of its abdomen, killing itself in the process. Wasps, hornets, and yellow jackets, lacking barbs or their stingers, can attack again and again.
Ticks cause no symptoms while they're biting. The only way to find them is to examine your skin each night. Serious complications of tick bites (Lyme disease and tick paralysis) normally only occur after the tick has been attached for at least 24 hours, so a nightly examination when in tick-infested areas is normally sufficient. For details about the symptoms of Lyme disease, go to the Lyme disease article. The main symptom of tick paralysis is muscle weakness, poor coordination, or paralysis spreading upwards (towards the head) from the site of a tick bite or an attached tick.
Most people can guess at what's bitten them from the site of the wound or welt. Blackflies, for example, leave bites around the head, neck and ears; while fleas often bite repeatedly around the feet and lower legs. Bedbugs tend to leave lines of bites, usually on the torso. While their bites can be extremely itchy, these creatures don't cause serious diseases or reactions.
The most serious reactions occur from stings of the various yellow-and-black flying insects. A major allergic reaction that interferes with breathing is called anaphylaxis or anaphylactic shock. Histamine, a chemical released by the body during most allergic reactions, is released into the skin after any insect bite and is responsible for the redness and itching. In anaphylaxis, histamine causes major itching and redness of the skin (urticaria, or hives), and may also be released in the airways, the lungs, and other vital organs. It causes tissue to swell, can close the airways, causing breathing to stop, and can drop blood pressure to dangerously low levels.
Anaphylaxis can occur after a single bite, but it's rare. More typically, fatal anaphylaxis occurs when somebody gets stung many times (50-100), though still nowhere near enough times to kill a non-allergic person.