Insect bites and stings cause skin reactions, such as itching, rashes, and sometimes swelling. While most bites and stings can be safely treated at home, those that cause allergic reactions may require prompt medical attention. If you think that you are having a severe allergic reaction, seek medical help immediately.

Causes

Insect bites and stings are caused by biting insects (eg, mosquitoes, fleas, ticks, and spiders) or stinging insects (eg, bees, yellow jackets, hornets, wasps, and fire ants).

Risk Factors

The following factors increase your chances of being bitten or stung by an insect:

• Performing work or spending time outdoors

• Living in warmer climates

• Lacking proper protection

• Forgetting to use flea and tick preventive measures for pets

• Collecting insects as a hobby

Symptoms

If you experience any of these symptoms do not assume it is only because of an insect bite. These symptoms may be caused by other health conditions. If you experience any one of them, see your physician.

The most common symptoms of insect bites and stings include:

• Mild swelling around the affected area

• Redness around the affected area

• Pain around the affected area

• Heat around the affected area

• Itching around the affected area

If you experience a severe allergic reaction as a result of an insect bite or sting, get medical help immediately. Symptoms of a severe allergic reaction include:

• Shortness of breath

• Wheezing

• Swelling, redness, or hives covering most of your body

• A feeling that your throat is closing up

• Nausea or vomiting

• Chills, muscle aches, or cramps

• Weakness

• Fever

• Abdominal pain

• Headache sweating

Diagnosis

Your doctor will ask about your symptoms and medical history, and perform a physical exam.

If the insect bite requires medical attention, your doctor will evaluate your symptoms and determine if you are having an allergic reaction or other medical problem caused by the bite or sting. He or she will ask you about the type of insect that bit or stung you. If possible, try to obtain a sample of the insect responsible for the bite or sting. If you were bitten by a spider and were able to safely kill it, take the spider to the doctor with you.

Treatment

Most insect bites and stings can be safely treated at home. If this is the case, take the following steps:

• If there is a stinger, carefully remove it by scraping it with a sharp edge, such as a credit card.

• If you find a tick, carefully remove it from the head as soon as possible. Tweezers are often effective in doing this.

• Wash the affected area thoroughly with soap and water.

• Place an ice pack or cold compress on the affected area for 15 minutes every few hours.

• If necessary, use calamine lotion, antihistamines, or a topical steroid cream (eg, hydrocortisone) to alleviate itching.

• If necessary, take pain relievers such as acetaminophen or ibuprofen to reduce swelling and pain.

If you were bitten by a brown recluse or black widow spider, or are unsure of what type of spider bit you and you feel sick, get medical treatment quickly. Treatment may include:

• Stabilization of symptoms you are experiencing

• Medications to reduce pain

• Antivenin administration to rapidly relieve symptoms

If you or someone you know is experiencing a severe allergic reaction as a result of an insect sting, seek medical help immediately. Once you arrive at the hospital, treatment may include:

• Emergency treatment to stabilize life-threatening symptoms

• Medications, such as epinephrine, antihistamines, and/or corticosteroids

• Intravenous fluids

• Oxygen venom immunotherapy–administering increasing doses of venom to stimulate your immune system to reduce the risk of a future allergic reaction

Prevention

To help reduce your chances of getting an insect bite or sting, take the following steps:

• Use insect repellants, which work against biting insects such as mosquitoes.

• Use caution around areas where insects nest, such as walls, bushes, trees, and open garbage cans.

• Reduce the amount of skin exposed when you are outdoors.

• Regularly treat your home for fleas during warmer months.

• Treat fire ant mounds with insecticides.

• Never swat at a flying insect.

• Keep foods covered as much as possible when eating outdoors.

• Cover outdoor garbage cans with tight-fitting lids.

• Avoid sweet-smelling perfumes, deodorants, lotions, hair sprays, and colognes.

• Avoid wearing bright colors.

• Wear gloves when gardening.

• Stay away from areas where mosquitoes breed, such as areas around still water.

• Stay inside at dawn and dusk, when mosquitoes are most active.

• Do not disturb bee or wasp nests.

• Be cautious in areas where spiders might be hiding, such as undisturbed piles of wood, seldom-opened containers, or corners behind furniture.

• Use flea and tick control for pets.

RESOURCES:

American College of Allergy, Asthma, and Immunology
http://www.acaai.org

National Institute of Allergy and Infectious Diseases
http://www3.niaid.nih.gov

Nemours Foundation
http://kidshealth.org

CANADIAN RESOURCES:

Allergy/Asthma Information Association
http://www.aaia.ca

Canadian Centre for Occupational Health and Safety
http://www.ccohs.ca

References:

The buzz on insect bites and stings. Nemours Foundation website. Available at: http://www.kidshealth.org/teen/safety/first_aid/bug_bites.html. Accessed October 5, 2006.

Clark S, Camargo CA Jr. Emergency treatment and prevention of insect-sting anaphylaxis. Curr Opin Allergy Clin Immunol. 2006;6:279-83.

Graft DF. Insect sting allergy. Med Clin North Am. 2006;90:211-32.

Insect stings. Medem website. Available at: http://www.medem.com/medlb/article_detaillb.cfm?article_ID=ZZZMO0FIA9C&sub_cat=530. Accessed October 5, 2006.

Moffitt JE, Golden DB, Reisman RE, et al. Stinging insect hypersensitivity :a practice parameter update. J Allergy Clin Immunol. 2004; 114:869-86.