Insect Bites and Stings

What kinds of reactions do insect bites cause?

For most people, a minor insect bite or sting may cause a little swelling and itching. The site may be painful for a few hours. Mosquitoes, biting flies, and some spiders usually cause mild reactions. Yellow jackets, honeybees, paper wasps, hornets, and fire ants cause more severe sting reactions.

Everyone reacts to the toxic effects of insect venom, for example, from a bee sting. Most people have mild reactions, which may appear in a few minutes or up to 48 hours after the bite or sting. Some people have insect allergies, which may cause mild to severe allergic reactions. Mildly allergic people may have hives with intense itching and pain around the site as well as eye itching. Others may have blisters where they were bitten.

A severe allergic reaction to a bite will happen within minutes of the bite. The symptoms may include:

severe swelling of the lips, tongue, or throat
trouble breathing
nausea, cramping, diarrhea, or vomiting
hives
dizziness
loss of consciousness.

How are insect bites treated?

If you are stung by a bee, remain calm and brush away the insect. Bees leave a stinger in your skin, but hornets, wasps, and yellow jackets typically do not. Remove a stinger within 30 seconds by scraping it with a fingernail. Do not squeeze the stinger, or it will likely release more venom.

When you are bitten by a tick, remove the tick right away using fine-tipped tweezers to grasp it firmly close to the skin. Do not squeeze the tick's body. You may want to save the tick for identification in case you become ill. This may help your health care provider make an accurate diagnosis. Place the tick in a sealable plastic bag and put it in your freezer. Wash your hands after touching the tick. Wash the bite area and put an antiseptic on it. See your provider if you start having symptoms such as a rash, fever, muscle aches, or joint pain.

If you have a mild reaction to an insect bite or sting:

Make a paste of 3 teaspoons baking soda and 1 teaspoon water and rub the area of the bite or sting with it.
Put a cold, moist cloth or ice cubes on the bitten area.
Put hydrocortisone cream, calamine lotion, or antihistamine cream on the area to help reduce itching and swelling.
Elevate the bitten area, if possible, to help prevent swelling.

If you are bitten by a spider or stung by a scorpion, put a cloth-covered ice pack on the area. If the scorpion or spider may be poisonous, go to the emergency room. Urgent care for a poisonous bite is especially important for children or older adults. If it can be done safely, take the spider in a jar to the emergency room, so it can be identified.

If you know you are allergic to some insect stings, ask your health care provider about carrying an injection kit of epinephrine, such as EpiPen or Ana-Kit. With the kit you can give yourself a shot of medicine to counteract the allergic reaction until medical help arrives. Wear a Medic Alert ID that warns of your allergy and tells what to do in case of an emergency. Tell your family, friends, and co-workers what they should do if you have a severe allergic reaction.

A severe allergic reaction is life-threatening. Call 911 immediately if someone is bit and has the symptoms of a severe reaction. If the person carries an injection kit, use it right away. Cardiopulmonary resuscitation (CPR) may be necessary. If the person has stopped breathing or his or her heart has stopped beating.

How can I help prevent insect bites?

Follow these guidelines to help prevent insect bites:

Avoid walking barefoot or wearing open-toe shoes when outdoors.
Do not wear clothing that is loose or brightly colored.
Avoid perfume.
Do not disturb beehives or hornet nests.
Keep food and soft drinks covered, and keep garbage cans tightly covered.
To avoid mosquito bites or tick bites, keep the body covered. Stay away from where mosquitoes breed. Use an insect repellent whenever you are outdoors. Don't use more repellent than recommended in the package directions. Don't put repellent on open wounds or rashes. Do not apply it to your eyes or mouth. When using sprays, do not spray it directly on your face--spray the repellent on your hands first and then put it on your face. Wash the spray off your hands. Be careful with children because repellents can make them ill.

Repellent products containing either DEET or picaridin as active ingredients have been proven to provide longer-lasting protection than others.
- Adults should use products with no more than 35% DEET. Children should use repellents with no more than 10% DEET. DEET should be washed off your body when you go back indoors.
- In some studies, oil of lemon eucalyptus, a plant-based repellent, provided as much protection as repellents with low concentrations of DEET, but it hasn't been as well tested as DEET. Oil of lemon eucalyptus should not be used on children under age 3.
- Picaridin is a repellent just recently made available in the US. It can be less irritating to the skin than DEET.
- Some products containing permethrin are recommended for use on clothing, shoes, bed nets, and camping gear. Permethrin is highly effective as an insecticide and as a repellent. Permethrin-treated clothing repels and kills ticks, mosquitoes, and other insects and continues to work after repeated laundering. The permethrin insecticide should be reapplied according to the label instructions. Some commercial products are available pretreated with permethrin. Don't put permethrin on your skin.

It is also important to prevent the possibility of getting a tetanus infection. The skin broken by an insect bite could become infected with tetanus bacteria. You can prevent this type of infection by keeping up to date with tetanus booster shots.

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

HIA File SFY4945F.HTM Release 9.0/2006