Local Reaction to an Insect Sting
You have been stung or bitten by an insect. The insect’s venom or body fluid is causing your skin to react in the area where you were stung or bitten. This often causes redness, itching, and swelling. This reaction will often fade over a few hours. But it can last a few days.
Common stinging insects that cause reactions are wasps, bees, yellow jackets, fire ants, and hornets. Common bites are from spiders, mosquitoes, fleas, or ticks. Other types of insects may be more common in different parts of the country or world.
Insect venom causes "local" toxic reactions in everyone. A local reaction means that symptoms only affect the part of the body where the sting or bite happened. The reaction didn't spread to a larger area of your body. Allergic reactions occur only in those who are already sensitive to the venom. The severity of your reaction to the insect sting depends on the dose of venom and the degree to which you are already sensitive to it. Most people think of allergic reactions when someone has a rash or itchy skin. But most stings cause local symptoms that are not allergic. These symptoms can include:
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Rash, redness, welts, or blisters around the sting or bite
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Itching, burning, stinging, or pain
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Swelling around the sting area, which may spread and become uncomfortable
An insect bite or sting can become infected 1 to 3 days later. So watch for the signs below. Sometimes it's hard to tell the difference between a local reaction to the insect bite or sting and an early infection. Your healthcare provider may give you antibiotics.
Home care
Medicines
The healthcare provider may prescribe medicines to ease swelling, itching, and pain. Follow the provider’s instructions when taking these medicines.
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Diphenhydramine is an oral antihistamine you can find in stores. You can use this medicine to reduce itching and swelling. The medicine may make you sleepy. So be careful using it in the daytime or when going to school, working, or driving. Don’t use diphenhydramine if you have glaucoma or if you have trouble urinating because of an enlarged prostate. Other antihistamines may cause less drowsiness. They may be better choices for daytime use. Ask your pharmacist for suggestions.
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If you have large areas of localized swelling, you may be prescribed oral corticosteroids, such as prednisone. These can help decrease the swelling and discomfort.
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Don’t use diphenhydramine cream on your skin. In some people, it can cause more of a localized skin rash due to allergy to the cream.
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Calamine lotion or oatmeal baths sometimes help with itching.
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You may use acetaminophen or ibuprofen to control pain, unless another pain medicine was prescribed. Talk with your healthcare provider before using these medicines if you have chronic liver or kidney disease. Also talk with your provider if you’ve had a stomach ulcer or gastrointestinal (GI) bleeding.
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If you had a severe reaction, the provider may prescribe epinephrine. Epinephrine is an emergency medicine that will stop an allergic reaction from getting worse. Before you leave the hospital, be sure that you understand when and how to use this medicine.
General care

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If itching is a problem, don’t take hot showers or baths. Stay out of direct sunlight. Warm skin will make the itching worse.
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Use an ice pack to reduce local areas of redness, swelling, and itching. You can make your own ice pack by putting ice cubes in a bag that seals at the top. Wrap the bag in a thin towel. Don’t put the ice directly on your skin, because it can damage the skin. Apply the ice pack for 5 to 10 minutes.
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Try not to scratch any affected areas to prevent damage to the skin or infection.
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If oral antibiotics or oral corticosteroids were prescribed, be sure to take them as directed until finished.
Tips for dealing with insect stings
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Be aware that honeybees nest in trees. Wasps and yellow jackets nest in the ground, trees, or roof eaves.
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When outdoors, don't wear perfume, cologne, sandals, or colorful clothing. Don't go barefoot. Don't swat at flying insects. Be careful when eating outside. Keep food and drinks covered.
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If you're stung by a honeybee, a stinger may remain in your skin. Wasps, yellow jackets, and hornets don’t leave a stinger behind. Move away from the nest area right away. The stinger of a honeybee releases a substance that will attract other bees to you. Once you're away from the nest, remove the stinger as quickly as possible. One suggested method is to scrape the stinger with a thin, dull edge. This could be the edge of a credit card or the dull side of a thin table knife. Don't pinch the stinger with your fingers or tweezers. This releases more venom into the skin.
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After any sting, you may apply ice and take diphenhydramine or another antihistamine. If you develop any of the warning signs below, get help right away.
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If your reaction includes dizziness, fainting, or trouble breathing or swallowing, ask your healthcare provider if you need epinephrine.
Follow-up care
Follow up with your healthcare provider in 2 days, or as advised, if your symptoms don’t start to get better. You may be referred to an allergist for more testing and treatment.
Call 911
Use your epinephrine if you have it and call 911 right away if any of these occur:
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Trouble breathing or swallowing, or wheezing
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Swelling in the mouth, throat, face, or tongue that is new or getting worse
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Hoarse voice, tight throat, or trouble speaking
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Confusion
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Severe drowsiness or trouble waking up
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Fainting, dizziness, or loss of consciousness
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Fast heart rate
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Low blood pressure
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Feeling of doom
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Nausea, vomiting, abdominal pain, or diarrhea
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Vomiting blood, or large amounts of blood in stool
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Seizure
When to get medical advice
Call your healthcare provider or get medical care right away if any of these occur:
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Spreading areas of itching, redness, or swelling
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New or worse swelling in the face, eyelids, or lips
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Dizziness or weakness
Also call your provider right away if you have signs of infection:
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Increasing pain, redness, or swelling
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Fever of 100.4°F (38°C) or higher, or as advised by your provider
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Fluid or pus draining from the sting area