What kinds of reactions do insect bites cause?

For most people, a minor insect bite or sting may cause a little pain, swelling, redness, and itching. The skin irritation may appear in a few minutes or up to 48 hours after the bite or sting. The site may be painful for several hours.

Some people have insect allergies, which may cause mild to severe allergic reactions. Symptoms of an allergic reaction depend on how severe your reaction is.

A mild allergic reaction may cause hives with intense itching and pain around the site as well as itching of the eyes. It may cause blisters in the area of the bite or sting.

A severe allergic reaction usually happens within minutes of the bite or sting and it can affect the whole body, causing serious symptoms. The symptoms may include:

• severe swelling of the lips, tongue, or throat

• trouble breathing

• nausea, cramping, diarrhea, or vomiting

• hives

• dizziness

• loss of consciousness

Mosquitoes, biting flies, bedbugs, and some spiders usually cause mild reactions. Yellow jackets, honeybees, paper wasps, hornets, and fire ants cause more severe reactions.

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 healthcare 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:

• Wash the area that was stung or bitten.

• 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 covered bag of ice on the area 3 to 4 times a day for 15 to 20 minutes. Never put ice directly on your skin. This could cause frostbite.

• Put hydrocortisone cream or calamine lotion on the area to help lessen itching and swelling. If the bite is still itchy, take an oral antihistamine such as Benadryl (which may make you drowsy).

• If the bite is painful, take acetaminophen or ibuprofen. Ibuprofen is an NSAID. Nonsteroidal anti-inflammatory medicines (NSAIDs) may cause stomach bleeding and other problems. These risks increase with age. Read the label and take as directed. Unless recommended by your healthcare provider, do not take NSAIDs for more than 10 days for any reason.

• Rest the bitten area on a pillow higher than your heart as much as possible for the first 1 to 2 days. This can 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 or scorpion in a jar to the emergency room, so it can be identified.

If you know you are allergic to some insect stings, ask your healthcare provider about carrying an injection kit of epinephrine, such as EpiPen. 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 right away if someone is stung or bitten and has the symptoms of a severe reaction or if they have a history of severe reactions. If the person carries an injection kit, use it right away. Start cardiopulmonary resuscitation (CPR) if the person has stopped breathing or has no pulse.

Call 911 right away if:

• You start to have trouble breathing, trouble swallowing, or feel tightness in your throat.

• Your throat or tongue is swelling.

• You feel weak, dizzy, or lightheaded.

Call your healthcare provider if:

• You have itching or hives that are getting worse.

• The bite area is becoming more swollen or more painful.

• The bite area is beginning to look infected.

  • The bitten area gets redder or more painful or swollen.

  • You see red streaks from the bite toward the center of your body.

  • The area gets very warm to touch.

  • Pus or other fluid is draining from the bite.

  • You have swollen glands, a fever higher than 101.5°F (38.6°C), chills, nausea, vomiting, or muscle aches.

• Any of your symptoms are getting worse instead of better.

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 wearing perfume or using scented lotions.

• 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 with long-sleeved shirts, long pants, and closed-toe shoes. Stay away from places 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. Then 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 give longer-lasting protection than others.
  
  

  • Adults should use products with no more than 35% DEET. Children older than 2 months can use repellents with no more than 30% DEET. DEET should be washed off your body when you go back indoors.

  • Picaridin may irritate the skin less than DEET.

  • 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.

  • 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 to the clothing according to the label instructions. Some commercial products are available pretreated with permethrin. Don't put permethrin directly on your skin.

• To get rid of bedbugs, call an exterminator to treat your home.

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 shots. Adults should have a tetanus booster shot every 10 years.

Developed by RelayHealth.
Published by RelayHealth.
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
© 2018 RelayHealth and/or its affiliates. All Rights Reserved.

Courtesy of University Health Services, The University of Texas at Austin.
Published by the University of Texas at Austin University Health Services.
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
©2023 The University of Texas at Austin. All Rights Reserved.