Insect Bites and Stings and Spider Bites

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Overview

Insect and spider bites often cause minor swelling, redness, pain, and itching. These mild reactions are common. They may last from a few hours to a few days. Home treatment is often all that's needed to relieve the symptoms of a mild reaction to common stinging or biting spiders and insects, such as fleas, flies, and mosquitoes.

Some people have more severe reactions to bites or stings. Babies and children may be more affected than adults are.

Examples of problems that are more serious include:

  • A severe allergic reaction (anaphylaxis). These reactions aren't common. But they can be life-threatening and require emergency care. They may cause:
    • Shock. This can occur if the circulatory system can't get enough blood to the vital organs.
    • Coughing, wheezing, trouble breathing, or a feeling of fullness in the mouth or throat.
    • Swelling of the lips, tongue, ears, eyelids, palms of the hands, soles of the feet, and mucous membranes (angioedema).
    • Lightheadedness and confusion.
    • Belly pain, nausea, vomiting, or diarrhea.
    • Raised, red, itchy bumps called hives and red skin. These symptoms often occur with other symptoms of a severe reaction.
  • A toxic reaction to a single sting or bite. Spiders or insects that may cause this include:
  • A toxic reaction to multiple stings or bites from a bee, wasp, or fire ant.
    • A bee leaves its stinger behind and then dies after stinging. Africanized honeybees, the so-called killer bees, are more aggressive than common honeybees. They often attack together in great numbers. Reaction to bee stings can range from minor skin swelling and redness to a serious allergic reaction.
    • Wasps, including hornets and yellow jackets, can sting over and over.
    • A fire ant is a wingless insect. It attaches to a person by biting with its jaws. Then, pivoting its head, it stings from its belly in a circular pattern at multiple sites.
  • A large skin reaction with swelling and redness that spreads away from the site of the bite or sting. It may be as large as swelling across two major joints, such as from the elbow to the shoulder.
  • A skin infection at the site of the bite or sting.
  • Serum sickness. This is a reaction to the medicines (antiserum) used to treat a bite or sting. It may cause hives and flu-like symptoms, such as a fever, muscle aches, or a headache about 3 to 21 days after the use of antiserum.
  • A virus infection. Infected mosquitoes can spread the West Nile virus to people, causing an inflammation of the brain (encephalitis).
  • A parasite infection. Infected mosquitoes can spread malaria.

Common insects and spiders

Insects that cause mild reactions include:

  • Bedbugs.
  • Kissing bugs.
  • Chiggers.
  • Fleas.
  • Flies.
  • Mites.
  • Mosquitoes.
  • Nonpoisonous spiders.
  • Ticks.
  • Scabies.
  • Lice.

Some insects are more likely than others to cause allergic or toxic reactions.

  • A bee leaves its stinger behind and then dies after stinging. Africanized honeybees, the so-called killer bees, are more aggressive than common honeybees and often attack together in great numbers. Reaction to bee stings can range from minor skin swelling and redness to a serious allergic reaction.
  • Wasps, including hornets and yellow jackets, can sting over and over. Yellow jackets cause the greatest number of allergic reactions.
  • A fire ant attaches to a person by biting with its jaws. Then, pivoting its head, it stings from its abdomen in a circular pattern at multiple sites.

Check Your Symptoms

Have you been bitten or stung by an insect or spider?
Yes
Insect or spider bite or sting
No
Insect or spider bite or sting
How old are you?
Less than 1 year old
Less than 1 year
1 to 11 years
1 to 11 years
12 years or older
12 years or older
Are you male or female?
Male
Male
Female
Female

The medical assessment of symptoms is based on the body parts you have.

  • If you are transgender or nonbinary, choose the sex that matches the body parts (such as ovaries, testes, prostate, breasts, penis, or vagina) you now have in the area where you are having symptoms.
  • If your symptoms aren’t related to those organs, you can choose the gender you identify with.
  • If you have some organs of both sexes, you may need to go through this triage tool twice (once as "male" and once as "female"). This will make sure that the tool asks the right questions for you.
Do you have a concern about a tick bite?
Yes
Tick bite concern
No
Tick bite concern
Did the bite or sting involve the eyeball?
Yes
Bite or sting to eyeball
No
Bite or sting to eyeball
Could you be having a severe allergic reaction?
This is more likely if you have had a bad reaction to something in the past.
Yes
Possible severe allergic reaction (anaphylaxis)
No
Possible severe allergic reaction (anaphylaxis)
Do you have symptoms of shock?
Yes
Symptoms of shock
No
Symptoms of shock
Have you ever had a severe allergic reaction to a bite or sting?
A severe allergic reaction affects the whole body. Your doctor may have called it anaphylaxis.
Yes
History of severe allergic reaction to bite or sting
No
History of severe allergic reaction to bite or sting
In the past 2 days, were you exposed to that same allergen, and are you now having symptoms of an allergic reaction?
Even if the symptoms do not start right away or are mild at first, they may quickly become severe.
Yes
History of severe reaction with symptoms now
No
History of severe reaction with symptoms now
Is there any serious swelling?
This could include swelling that is not near the bite or sting area, or swelling that began at the bite or sting site but is expanding well beyond that area. (Some swelling at the site of the bite or sting is normal.)
Yes
New or expanding swelling not near bite or sting
No
New or expanding swelling not near bite or sting
Are the lips, tongue, mouth, or throat swollen?
Yes
Swelling of lips, tongue, mouth, or throat
No
Swelling of lips, tongue, mouth, or throat
Did the lips, tongue, mouth, or throat swell quickly?
Yes
Rapid swelling of lips, tongue, mouth, or throat
No
Rapid swelling of lips, tongue, mouth, or throat
Does swelling involve the palms of the hands, the soles of the feet, or the area from one large joint to another, such as from the ankle to the knee?
Yes
Swelling is across two joints, on soles of feet, or on palms of hands
No
Swelling is across two joints, on soles of feet, or on palms of hands
Is the swelling getting worse (over hours or days)?
Yes
Swelling is getting worse
No
Swelling is getting worse
Did you get an epinephrine shot to treat the reaction?
Yes
Has had epinephrine shot
No
Has had epinephrine shot
Have you been bitten or stung by a poisonous spider (such as a black widow or brown recluse spider), a scorpion, or a caterpillar?
Yes
Bitten or stung by poisonous spider, scorpion, or caterpillar
No
Bitten or stung by poisonous spider, scorpion, or caterpillar
Are there any hives?
Hives are raised, red, itchy patches of skin. They usually have red borders and pale centers. They may seem to move from place to place on the skin.
Yes
Hives
No
Hives
Do the hives cover many places on your body?
Yes
Hives in many places
No
Hives in many places
Did the hives appear within 3 hours after the bite or sting?
Yes
Hives developed within 3 hours of bite or sting
No
Hives developed within 3 hours of bite or sting
Are there any symptoms of infection?
Yes
Symptoms of infection
No
Symptoms of infection
Do you think you may have a fever?
Yes
Possible fever
No
Possible fever
Are there red streaks leading away from the area or pus draining from it?
Yes
Red streaks or pus
No
Red streaks or pus
Do you have diabetes, a weakened immune system, peripheral arterial disease, or any surgical hardware in the area?
"Hardware" includes things like artificial joints, plates or screws, catheters, and medicine pumps.
Yes
Diabetes, immune problems, peripheral arterial disease, or surgical hardware in affected area
No
Diabetes, immune problems, peripheral arterial disease, or surgical hardware in affected area
Have you developed any flu-like symptoms after the bite or sting, such as fever, shaking chills, muscle or joint pain, headache, or a general feeling of illness?
This could happen within minutes of the bite or sting or up to 3 weeks later.
Yes
Flu-like symptoms
No
Flu-like symptoms
Did these symptoms begin within minutes after the bite or sting?
Yes
Flu-like symptoms began within minutes after bite or sting
No
Flu-like symptoms began within minutes after bite or sting
Do you have other symptoms, such as belly pain, vomiting, or diarrhea?
Yes
Has other symptoms, such as belly pain, vomiting, or diarrhea
No
Has other symptoms, such as belly pain, vomiting, or diarrhea
Did these symptoms begin within minutes after the bite or sting?
Yes
Other symptoms began within minutes after bite or sting
No
Other symptoms began within minutes after bite or sting
Have tiny red or purple spots or bruises appeared suddenly?
Yes
Sudden appearance of red or purple spots or bruising
No
Sudden appearance of red or purple spots or bruising
Is there a blister, a painful sore, or a purple discoloration at the site of a bite or sting?
Yes
Blister, painful sore, or purple discoloration at bite or sting site
No
Blister, painful sore, or purple discoloration at bite or sting site
Are you having new muscle spasms or stiffness?
Yes
Muscle spasms or stiffness after bite or sting
No
Muscle spasms or stiffness after bite or sting
Do you have pain at the site of the bite or sting?
The pain may feel like a burning pain. It may be very bad for several minutes right after the bite. You may still have some pain hours later.
Yes
Pain or burning pain at site of bite or sting
No
Pain or burning pain at site of bite or sting
How bad is the pain on a scale of 0 to 10, if 0 is no pain and 10 is the worst pain you can imagine?
8 to 10: Severe pain
Severe pain
5 to 7: Moderate pain
Moderate pain
1 to 4: Mild pain
Mild pain
Has the pain lasted for more than 8 hours?
Yes
Pain for more than 8 hours
No
Pain for more than 8 hours
Is the pain getting worse?
Yes
Pain is getting worse
No
Pain is getting worse
Have you tried home treatment for more than 2 days?
Home treatment includes things like using ice on the area, taking an antihistamine, and taking pain medicine such as acetaminophen (Tylenol) or ibuprofen (Advil, Motrin).
Yes
Home treatment for more than 2 days
No
Home treatment for more than 2 days
Did you get more than one bite or sting?
This does not include mosquito bites.
Yes
More than 1 bite or sting
No
More than 1 bite or sting
Was there more than one bite or sting from bees, wasps, hornets, yellow jackets, or fire ants?
Yes
2 or more bites or stings from bees, wasps, hornets, yellow jackets, or fire ants
No
2 or more bites or stings from bees, wasps, hornets, yellow jackets, or fire ants
Did you get at least 5 bites or stings from bees, wasps, hornets, yellow jackets, or fire ants?
Yes
5 or more bites or stings from bees, wasps, hornets, yellow jackets, or fire ants
No
5 or more bites or stings from bees, wasps, hornets, yellow jackets, or fire ants
Did you get at least 10 bites or stings from bees, wasps, hornets, yellow jackets, or fire ants?
Yes
10 or more bites or stings from bees, wasps, hornets, yellow jackets, or fire ants
No
10 or more bites or stings from bees, wasps, hornets, yellow jackets, or fire ants
Do you think you may need a tetanus shot?
Yes
May need tetanus shot
No
May need tetanus shot
Have symptoms lasted for more than a week after the bite or sting?
Yes
Symptoms for more than 1 week after bite or sting
No
Symptoms for more than 1 week after bite or sting

Many things can affect how your body responds to a symptom and what kind of care you may need. These include:

  • Your age. Babies and older adults tend to get sicker quicker.
  • Your overall health. If you have a condition such as diabetes, HIV, cancer, or heart disease, you may need to pay closer attention to certain symptoms and seek care sooner.
  • Medicines you take. Certain medicines, such as blood thinners (anticoagulants), medicines that suppress the immune system like steroids or chemotherapy, herbal remedies, or supplements can cause symptoms or make them worse.
  • Recent health events, such as surgery or injury. These kinds of events can cause symptoms afterwards or make them more serious.
  • Your health habits and lifestyle, such as eating and exercise habits, smoking, alcohol or drug use, sexual history, and travel.

Try Home Treatment

You have answered all the questions. Based on your answers, you may be able to take care of this problem at home.

  • Try home treatment to relieve the symptoms.
  • Call your doctor if symptoms get worse or you have any concerns (for example, if symptoms are not getting better as you would expect). You may need care sooner.

Symptoms of a severe allergic reaction (anaphylaxis) may include:

  • The sudden appearance of raised, red areas (hives) all over the body.
  • Rapid swelling of the throat, mouth, or tongue.
  • Trouble breathing.
  • Passing out (losing consciousness). Or you may feel very lightheaded or suddenly feel weak, confused, or restless.
  • Severe belly pain, nausea, vomiting, or diarrhea.

A severe reaction can be life-threatening. If you have had a bad allergic reaction to a substance before and are exposed to it again, treat any symptoms as an emergency. Even if the symptoms are mild at first, they may quickly become very severe.

Symptoms of infection may include:

  • Increased pain, swelling, warmth, or redness in or around the area.
  • Red streaks leading from the area.
  • Pus draining from the area.
  • A fever.

Pain in adults and older children

  • Severe pain (8 to 10): The pain is so bad that you can't stand it for more than a few hours, can't sleep, and can't do anything else except focus on the pain.
  • Moderate pain (5 to 7): The pain is bad enough to disrupt your normal activities and your sleep, but you can tolerate it for hours or days. Moderate can also mean pain that comes and goes even if it's severe when it's there.
  • Mild pain (1 to 4): You notice the pain, but it is not bad enough to disrupt your sleep or activities.

Pain in children under 3 years

It can be hard to tell how much pain a baby or toddler is in.

  • Severe pain (8 to 10): The pain is so bad that the baby cannot sleep, cannot get comfortable, and cries constantly no matter what you do. The baby may kick, make fists, or grimace.
  • Moderate pain (5 to 7): The baby is very fussy, clings to you a lot, and may have trouble sleeping but responds when you try to comfort him or her.
  • Mild pain (1 to 4): The baby is a little fussy and clings to you a little but responds when you try to comfort him or her.

Certain health conditions and medicines weaken the immune system's ability to fight off infection and illness. Some examples in adults are:

  • Diseases such as diabetes, cancer, heart disease, and HIV/AIDS.
  • Long-term alcohol and drug problems.
  • Steroid medicines, which may be used to treat a variety of conditions.
  • Chemotherapy and radiation therapy for cancer.
  • Other medicines used to treat autoimmune disease.
  • Medicines taken after organ transplant.
  • Not having a spleen.

Shock is a life-threatening condition that may quickly occur after a sudden illness or injury.

Adults and older children often have several symptoms of shock. These include:

  • Passing out (losing consciousness).
  • Feeling very dizzy or lightheaded, like you may pass out.
  • Feeling very weak or having trouble standing.
  • Not feeling alert or able to think clearly. You may be confused, restless, fearful, or unable to respond to questions.

Shock is a life-threatening condition that may occur quickly after a sudden illness or injury.

Babies and young children often have several symptoms of shock. These include:

  • Passing out (losing consciousness).
  • Being very sleepy or hard to wake up.
  • Not responding when being touched or talked to.
  • Breathing much faster than usual.
  • Acting confused. The child may not know where he or she is.

Usually found in dirt and soil, tetanus bacteria typically enter the body through a wound. Wounds may include a bite, a cut, a puncture, a burn, a scrape, insect bites, or any injury that may cause broken skin. Tetanus can also happen with other infections, like dental infections. It can happen during a surgery or pregnancy and delivery.

A wound can be so small, you may not notice you have one. Or a skin blister could break and become an open wound. If there is any delay in finding or cleaning a wound, there is an increased risk for skin infection and a chance for tetanus to get in the wound. A tetanus infection can start 3 to 21 days after the bacteria enter the wound. Be especially careful about wounds on your fingers and toes.

Many people may not know when they got their last tetanus shot. So it's a good idea to call your doctor to see if you need one.

Make sure to stay up to date on your tetanus shots. A tetanus shot is recommended:

  • For a dirty wound that has things like dirt, saliva, or feces in it, if you haven't had a tetanus shot in the past 5 years.
  • For a clean wound, if you haven't had a tetanus shot in the past 10 years.

Sudden tiny red or purple spots or sudden bruising may be early symptoms of a serious illness or bleeding problem. There are two types.

Petechiae (say "puh-TEE-kee-eye"):

  • Are tiny, flat red or purple spots in the skin or the lining of the mouth.
  • Do not turn white when you press on them.
  • Range from the size of a pinpoint to the size of a small pea and do not itch or cause pain.
  • May spread over a large area of the body within a few hours.
  • Are different than tiny, flat red spots or birthmarks that are present all the time.

Purpura (say "PURR-pyuh-ruh" or "PURR-puh-ruh"):

  • Is sudden, severe bruising that occurs for no clear reason.
  • May be in one area or all over.
  • Is different than the bruising that happens after you bump into something.

Seek Care Now

Based on your answers, you may need care right away. The problem is likely to get worse without medical care.

  • Call your doctor now to discuss the symptoms and arrange for care.
  • If you cannot reach your doctor or you don't have one, seek care in the next hour.
  • You do not need to call an ambulance unless:
    • You cannot travel safely either by driving yourself or by having someone else drive you.
    • You are in an area where heavy traffic or other problems may slow you down.

Call 911 Now

Based on your answers, you need emergency care.

Call 911 or other emergency services now.

Sometimes people don't want to call 911. They may think that their symptoms aren't serious or that they can just get someone else to drive them. Or they might be concerned about the cost. But based on your answers, the safest and quickest way for you to get the care you need is to call 911 for medical transport to the hospital.

Seek Care Today

Based on your answers, you may need care soon. The problem probably will not get better without medical care.

  • Call your doctor today to discuss the symptoms and arrange for care.
  • If you cannot reach your doctor or you don't have one, seek care today.
  • If it is evening, watch the symptoms and seek care in the morning.
  • If the symptoms get worse, seek care sooner.

Make an Appointment

Based on your answers, the problem may not improve without medical care.

  • Make an appointment to see your doctor in the next 1 to 2 weeks.
  • If appropriate, try home treatment while you are waiting for the appointment.
  • If symptoms get worse or you have any concerns, call your doctor. You may need care sooner.

Seek Care Now

Based on your answers, you may need care right away. The problem is likely to get worse without medical care.

  • Call your doctor now to discuss the symptoms and arrange for care.
  • If you cannot reach your doctor or you don't have one, go to the emergency room now. You may have a reaction after the epinephrine wears off.
  • You do not need to call an ambulance unless:
    • You cannot travel safely either by driving yourself or by having someone else drive you.
    • You are in an area where heavy traffic or other problems may slow you down.
Eye Injuries
Tick Bites

Self-Care

Caring for an insect bite or sting

Most bites and stings will heal on their own. Here are some things you can do at home.

  • Get away from the insect.

    Move away from the stinging or biting insect. Bees will alert other bees, making them more likely to sting.

  • Stay as calm and quiet as you can.

    Movement makes venom spread faster in the bloodstream.

  • Remove the stinger or spine.

    If you were stung by a bee and the stinger is still in the skin, remove the stinger as soon as you can.

    After contact with a puss caterpillar, remove broken-off spines. Do this by placing cellophane tape or commercial facial peel over the area of the contact and pulling it off.

    If you were stung by a scorpion, see a doctor right away. There is now a medicine (antidote) for scorpion stings.

  • Try cold, then heat.
    • Apply an ice pack to a bite or sting for 15 to 20 minutes once an hour for the first 6 hours. When you're not using ice, keep a cool, wet cloth on the bite or sting for up to 6 hours. Always keep a cloth between your skin and the ice pack. Don't apply ice for longer than 15 to 20 minutes at a time. Don't fall asleep with the ice on your skin.
    • After the first 6 hours, if you don't have swelling, try applying warmth to the site for comfort.
  • Try a nonprescription medicine to relieve itching, redness, and swelling.
    • An antihistamine that you take by mouth, such as fexofenadine (Allegra) or loratadine (Claritin), may help relieve itching, redness, and swelling.
    • A spray of local anesthetic containing benzocaine, such as Solarcaine, may help relieve pain. If your skin reacts to the spray, stop using it.
    • Hydrocortisone 1% cream or calamine lotion applied to the skin may help relieve itching and redness. You may need to check with your doctor first if you need to use the cream for a child younger than age 2 or for use in the genital area.

    These medicines may not be safe for young children or for people who have certain health problems. Before you use them, check the label. If you do use these medicines, always follow the directions about how much to use based on age and, in some cases, weight. You may need to check with your doctor about using these medicines.

  • Try other remedies.

    Some people try a home remedy, such as putting witch hazel or underarm deodorant on the bite. Home remedies haven't been proven scientifically to help. But they usually won't hurt you if you want to try them.

  • Watch for signs of a skin infection.

    Signs of infection include:

    • Increased pain, swelling, redness, or warmth around the bite.
    • Red streaks leading from the bite.
    • Pus draining from the bite.
    • A fever.
  • Prevent infection.
    • Wash the area with clean water 2 times a day.
    • Don't break any blisters that develop.
    • Try not to scratch the bite area. Trim fingernails to prevent scratching and infection.
    • Apply a bandage, if needed. You may cover the area with a thin layer of petroleum jelly, such as Vaseline, and a nonstick bandage. Apply more petroleum jelly and replace the bandage as needed.

Caring for a spider bite or scorpion sting

  • Put ice or a cold pack on the area for 10 to 20 minutes at a time. Put a thin cloth between the ice and your skin.
  • Try an over-the-counter medicine for itching, redness, swelling, and pain. Be safe with medicines. Read and follow all instructions on the label.
    • Take an over-the-counter antihistamine to help calm the itching or swelling.
    • Put a hydrocortisone 1% cream or calamine lotion on the skin.
  • Don't scratch or rub the skin around the area.

When to call for help during self-care

Call a doctor if any of the following occur during self-care at home:

  • New or worse signs of an infection, such as redness, warmth, swelling, or pus.
  • Flu-like symptoms, such as a fever, muscle aches, or chills.
  • Symptoms occur more often or are more severe.

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Credits

Current as of: July 10, 2023

Author: Healthwise Staff
Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.