Bothered by Bug Bites?

Jean-Pierre DHENIN, Family Medicine Physician

Beijing’s bug population waxes and wanes in a fairly predictable pattern. If you have lived in Beijing for more than a year, you know to expect a resurgence of bugs around this season. Most bugs are just annoying. But a few bugs can cause a lot of harm, and bug bites should be treated carefully, even with home remedies.

Common bugs and bites

The types of problems you can get from a serious bug bite depend on where you live. A mosquito might give you malaria in Africa or in southern Yunnan province, but will simply cause some itchiness or discomfort in regions with temperate weather.

Though unpleasant, most insect bites are harmless. Bee, wasp, and hornet stings and ant bites usually hurt. Mosquito, flea, and mite bites usually itch. Insect bites often result in redness and swelling in the injured area. But for some, stings can cause life-threatening allergic reactions.

Bees, wasps, hornets, and fire ants are members of the Hymenoptera family. Bites or stings from these species may cause serious reactions in people who are allergic to them. Deaths from bee stings are three to four times more common than deaths from snake bites. Bees, wasps, and ants differ in how they inflict injury. When a bee stings, it loses the entire stinger and it dies in the process. A wasp can inflict multiple stings because it does not lose its injection apparatus after it stings. Fire ants inject their venom by using their mandibles (the biting parts of their jaw) and rotating their bodies. Like wasps, fire ants can bite repeatedly.

In contrast, bites from mosquitoes typically do not cause significant illnesses, unless they carry harmful microorganisms. West Nile virus and malaria are caused by parasites carried by female mosquitoes.

Additional notes on insects, bites, and diseases relevant to Beijing

  • Lice can transmit epidemic relapsing fever, caused by spirochetes.
  • In unsanitary conditions, the common housefly can play a role in spreading human intestinal infections (such as typhoid and dysentery) by contaminating human food.
  • Tularemia can be spread by tick or fly bites and the bubonic plague by rodent fleas.
  • Ticks can transmit Lyme disease and other illnesses through their bites or stings.
  • Fleas are small, wingless insects that live off the blood of their hosts. They bite pets and people.
  • Bed bugs are also quite annoying but don’t spread germs that cause diseases in humans.

Responses to an insect sting or bite depend on a variety of factors. Most bites and stings result in pain, swelling, redness, and itching to the affected area. The skin may become infected if the bite area is scratched and the skin is broken. If not treated properly, these local infections may become severe and result in a condition known as cellulitis.

It is possible to get a severe general reaction if you are allergic to the bite or sting. This is known as anaphylaxis. Symptoms of a severe reaction include hives, wheezing, shortness of breath, unconsciousness, and even death within 30 minutes.

To protect yourself, apply insect repellent and cover up when you go outdoors. Window screens are also important to have for your home.

Treatment for bites

Treatment must match the type of reaction. If there is only redness and pain at the site of the bite, applying ice is adequate treatment. You’ll also want to clean the area with soap and water to remove any particles left behind by some insects (such as mosquitoes). These particles may further contaminate the wound if not removed.

Refrain from scratching because this may cause the skin to break and an infection to form. You may treat itching with an over-the-counter antihistamine cream or pill, such as diphenhydramine (a.k.a. Benadryl). Calamine lotion also helps relieve itching.

People who have a history of severe reactions to bites or stings may have been prescribed epinephrine (usually self-administered via an injection) and an antihistamine. Epinephrine must be used according to your doctor’s instructions.

Tips for prevention

  • Don’t bother insects.
  • Use insect repellant liberally.
  • Wear protective clothing.
  • Be careful when you eat outside because food attracts insects.
  • If you know you have severe allergic reactions to insect bites, carry an emergency epinephrine kit.