Health Library Insect Bites and Stings and Spider BitesFrom Healthwise

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

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

Examples of problems that are more serious include:

• A severe allergic reaction (anaphylaxis). Severe allergic reactions are not common but can be life-threatening and require emergency care. Signs or symptoms may include:
  • Shock, which may occur if the circulatory system cannot get enough blood to the vital organs.
  • Coughing, wheezing, difficulty breathing, or 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.
  • Nausea, diarrhea, and stomach cramps.
  • Hives and reddening of the 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:
  • Black widow spider.
  • Brown recluse spider.
  • Scorpion.
  • Puss caterpillar (woolly slug).
• 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 and often attack together in great numbers.
  • Wasps, including hornets and yellow jackets, can sting over and over.
  • A fire ant 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 at the site of the bite or sting.
• A skin infection at the site of the bite or sting.
• Serum sickness, a reaction to the medicines (antiserum) used to treat a bite or sting. Serum sickness may cause hives and flu-like symptoms in 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). For more information, see the topic West Nile Virus.
• A parasite infection. Infected mosquitoes can spread malaria. For more information, see the topic Malaria.

Review the Emergencies and Check Your Symptoms sections to determine if and when you need to see a doctor.

Health tools help you make wise health decisions or take action to improve your health.

	Decision Points focus on key medical care decisions that are important to many health problems.
	Should I have allergy shots for allergies to insect stings?

• Signs of shock occur:
  • In children.
  • In adults and older children.
• Moderate to severe difficulty breathing occurs:
  • In children.
  • In adults and older children.
• You have had a previous severe allergic reaction (anaphylaxis) to a similar bite or sting.
• Rapid swelling of the throat or tongue occurs.
• An uncontrolled jerking of muscles (seizure) occurs along with unresponsiveness. Protect the person from harm during the seizure.
• You have swelling of the eyeball (not around the eye or the eyelid).

Note:

Use an allergy kit prescribed by your doctor for a known allergy problem if all of the following are true: Your symptoms are severe. You have a kit immediately available. You have been instructed in how and when to use an allergy kit. You have had a severe reaction to the same or a similar insect or spider and you are beginning to have symptoms of a similar reaction.

Note:

Do not use the kit if you are not currently having any symptoms of an allergic reaction, even if you had a severe reaction in the past.

If you answer yes to any of the following questions, click on the "Yes" in front of the question for information about how soon to see a health professional.

Review health risks that may increase the seriousness of your symptoms.

If you have the following, evaluate those symptoms first.

• Tick bite: Go to the topic Tick Bites.

	Yes	Have you used an epinephrine shot to treat an allergic reaction or been accidentally stuck with an epinephrine shot?
When to See a Doctor See significance of using or being accidentally stuck by an epinephrine shot if you need information to help you answer the questions below. Review health risks that may increase the seriousness of your symptoms. Call your health professional immediately if you answer "Yes" to any of the following questions. Note: If you used an epinephrine shot to treat an allergic reaction, or if you were accidentally stuck with an epinephrine shot and are not able to contact your doctor: Go immediately to the nearest hospital emergency room for evaluation. Take the used epinephrine shot with you. Your doctor will want to inspect it and dispose of it properly. Yes Have you used an epinephrine shot to treat an allergic reaction? Yes Have you been accidentally stuck with an epinephrine shot? If you have answered "No" to the above questions, continue to answer the questions to evaluate your symptoms.
	Yes	Have you been bitten, stung, or had contact with a poisonous spider, scorpion, or puss caterpillar?
When to See a Doctor See significance of a bite, sting, or contact with a poisonous spider, scorpion, or caterpillar if you need information to help you answer the questions below. Review health risks that may increase the seriousness of your symptoms. Note: If you are not sure what bit or stung you, return to the Check Your Symptoms section. If you have been bitten, stung, or had contact with a poisonous spider, scorpion, or caterpillar and you are unable to talk with your doctor immediately, go to a hospital emergency room for treatment. For black widow or brown recluse spider bites or scorpion stings, take the following steps and seek immediate care: Remain calm. Too much excitement or movement increases the flow of venom into the blood. Apply a cool, wet cloth to the bite or cover the bite with a cloth and apply an ice bag to the bite. Do not apply a tourniquet. It may cause more harm than benefit. Call your health professional immediately if you answer "Yes" to any of the following questions. Yes Have you been bitten by a black widow spider? Yes Have you been bitten by a brown recluse spider? Yes Have you been stung by a scorpion? Yes Have you had contact with a puss caterpillar (woolly slug)? If you have answered "No" to the above questions, continue to answer the questions to evaluate your symptoms.
	Yes	Have you developed mild difficulty breathing or wheezing following a bite or sting?
When to See a Doctor See significance of mild difficulty breathing or wheezing if you need information to help you answer the questions below. Review health risks that may increase the seriousness of your symptoms. Call your health professional immediately if you answer "Yes" to the following question. Yes Do you have mild difficulty breathing or wheezing? Call your health professional today if you answer "Yes" to the following question. Yes Do you have long-term (chronic) mild breathing problems that have gradually gotten worse? If you have answered "No" to the above questions, continue to answer the questions to evaluate your symptoms.
	Yes	Do you have hives following a bite or sting?
When to See a Doctor See significance of hives if you need information to help you answer the questions below. Review health risks that may increase the seriousness of your symptoms. Call your health professional immediately if you answer "Yes" to the following question. Yes Do you have hives that came on suddenly in the past 1 to 3 hours and cover all or most of your body? Call your health professional today if you answer "Yes" to the following question. Yes Have hives appeared over several hours and now cover all or most of your body, but you do not have other symptoms? You may wait to see if the symptoms improve over the next 24 hours (or specified time period) if you answer "Yes" to any of the following questions. Yes Do you have hives that come and go but are still occurring after 24 hours of home treatment? Yes Do you have persistent hives that have not gone away after 24 hours of home treatment? If you have answered "No" to the above questions, continue to answer the questions to evaluate your symptoms.
	Yes	Do you have pain, burning, or numbness at the site of bite or sting?
When to See a Doctor See significance of pain, burning, or numbness at the site of bite or sting if you need information to help you answer the questions below. Review health risks that may increase the seriousness of your symptoms. Call your health professional immediately if you answer "Yes" to the following question. Yes Have you had severe pain, burning, or numbness for longer than a few minutes? Call your health professional today if you answer "Yes" to the following question. Yes Do you have moderate pain, burning, or numbness not relieved by home treatment? You may wait to see if the symptoms improve over the next 24 hours (or specified time period) if you answer "Yes" to the following question. Yes Do you still have mild pain, burning, or numbness after using home treatment for 24 hours? If you have answered "No" to the above questions, continue to answer the questions to evaluate your symptoms.
	Yes	Do you have tiny purple or red spots (petechiae) on your body following a bite or sting?
When to See a Doctor See significance of tiny purple or red spots (petechiae) if you need information to help you answer the questions below. Review health risks that may increase the seriousness of your symptoms. Call your health professional immediately if you answer "Yes" to any of the following questions. Yes Do you know or think you have a fever? Yes Do you have shaking chills? Yes Do you have a decreased level of activity or a vague feeling of illness (malaise)? Yes Do you have nausea, vomiting, or belly pain? Yes Do you have new joint pain or muscle stiffness? Call your health professional today if you answer "Yes" to the following question. Yes Do you have many new tiny, flat purple or red spots (petechiae) without other symptoms? If you have answered "No" to the above questions, continue to answer the questions to evaluate your symptoms.
	Yes	Do you have muscle spasms or muscle stiffness after a bite or sting?
When to See a Doctor See significance of muscle spasms or stiffness if you need information to help you answer the questions below. Review health risks that may increase the seriousness of your symptoms. Call your health professional immediately if you answer "Yes" to any of the following questions. Yes Do you have nausea, vomiting, or belly pain? Yes Do you have a headache or lightheadedness or think you may faint? Yes Do you know or think you have a fever? Yes Do you have shaking chills? Yes Are you drowsy (very sleepy, hard to wake up, or less alert)? Yes Is your blood pressure higher than normal? Call your health professional today if you answer "Yes" to the following question. Yes Do you have muscle spasms or stiffness without other symptoms? If you have answered "No" to the above questions, continue to answer the questions to evaluate your symptoms.
	Yes	Do you have a blister, painful sore, or purple discoloration at the site of a bite or sting?
When to See a Doctor See significance of a blister, painful sore, or purple discoloration if you need information to help you answer the questions below. Review health risks that may increase the seriousness of your symptoms. Call your health professional immediately if you answer "Yes" to any of the following questions. Yes Do you know or think you have a fever? Yes Do you have shaking chills? Yes Do you have a decreased level of activity or a vague feeling of illness (malaise)? Yes Do you have nausea, vomiting, or belly pain? Yes Do you have new joint pain or muscle stiffness? You may wait to see if the symptoms improve over the next 24 hours (or specified time period) if you answer "Yes" to the following question. Yes Have you had a blister, painful sore, or purple discoloration at the site of a bite or sting for 24 hours, but you do not have any other symptoms of illness? If you have answered "No" to the above questions, continue to answer the questions to evaluate your symptoms.
	Yes	Do you have new swelling?
When to See a Doctor See significance of new swelling if you need information to help you answer the questions below. Review health risks that may increase the seriousness of your symptoms. Call your health professional immediately if you answer "Yes" to any of the following questions. Yes Do you have swelling of the lips, tongue, throat, eyelids, or ears (but no trouble breathing), and the swelling is not where you were bitten or stung? Yes Do you have sudden swelling that is rapidly increasing, such as swelling across 2 large joints (for example, from the elbow to the shoulder)? Call your health professional today if you answer "Yes" to any of the following questions. Yes Do you have swelling that has gradually increased across 2 large joints, such as from the elbow to the shoulder? Yes Do you have swelling of the palms of the hands or the soles of the feet, and that is not where you were bitten or stung? You may wait to see if the symptoms improve over the next 24 hours (or specified time period) if you answer "Yes" to any of the following questions. Yes Do you have moderate swelling (an area about the size of your palm) that has not begun to improve after 24 hours of home treatment? Yes Is your eyelid still swollen completely shut 24 hours or longer after being bitten or stung near the eye? If you have answered "No" to the above questions, continue to answer the questions to evaluate your symptoms.
	Yes	Have you had multiple bites or stings, other than from mosquitoes?
When to See a Doctor See significance of multiple bites or stings if you need information to help you answer the questions below. Review health risks that may increase the seriousness of your symptoms. Call your health professional immediately if you answer "Yes" to any of the following questions. Yes Are you drowsy (very sleepy, hard to wake up, or less alert)? Yes Do you have swelling of the lips, tongue, throat, eyelids, or ears (but no trouble breathing), and the swelling is not where you were bitten or stung? Yes Do you have sudden swelling that is rapidly increasing, such as swelling across 2 large joints (for example, from the elbow to the shoulder)? Yes Do you feel lightheaded or think you may faint? Yes Do you have muscle spasms? Yes Do you have a headache? Yes Do you know or think you have a fever? Yes Do you have nausea, vomiting, or belly pain? Yes Do you have diarrhea? Call your health professional today if you answer "Yes" to any of the following questions. Yes Has your baby (younger than 1 year old) had 2 or more bites or stings from bees, wasps, hornets, yellow jackets, or fire ants? Yes Has your child between the ages of 1 and 10 years had 5 or more bites or stings from bees, wasps, hornets, yellow jackets, or fire ants? Yes Has an adult or a child older than 10 years had 10 or more bites or stings from bees, wasps, hornets, yellow jackets, or fire ants? If you have answered "No" to the above questions, continue to answer the questions to evaluate your symptoms.
	Yes	Have 2 or more flu-like symptoms developed within minutes or up to 3 weeks of a bite or sting?
When to See a Doctor See significance of flu-like symptoms if you need information to help you answer the questions below. Review health risks that may increase the seriousness of your symptoms. Call your health professional immediately if you answer "Yes" to the following question. Yes Have 2 or more of the following flu-like symptoms begun within a few minutes to a few hours after a bite or sting? Fever Shaking chills Vomiting Muscle cramps or spasms Joint aches Headache Swollen glands A vague feeling of illness (malaise) Rash Call your health professional today if you answer "Yes" to the following question. Yes Have 2 or more of the following flu-like symptoms begun within 3 weeks of a bite or sting? Fever Shaking chills Muscle cramps or spasms Joint aches Headache Swollen glands A vague feeling of illness (malaise) Rash If you have answered "No" to the above questions, continue to answer the questions to evaluate your symptoms.
	Yes	Do you think you have a skin infection at the site of a bite or sting?
When to See a Doctor See significance of signs of a skin infection if you need information to help you answer the questions below. Review health risks that may increase the seriousness of your symptoms. Call your health professional immediately if you answer "Yes" to any of the following questions. Yes Do you have diabetes? Yes Do you have peripheral arterial disease? Yes Do you have a disease or take medicine that causes problems with your immune system? Call your health professional today if you answer "Yes" to any of the following questions. Yes Do you have increased pain, swelling, redness, or warmth around a bite or sting? Yes Do you have red streaks extending from a bite or sting? Yes Do you have pus in or around a bite or sting? Yes Do you know or think you have a fever? You may wait to see if the symptoms improve over the next 24 hours (or specified time period) if you answer "Yes" to any of the following questions. Yes Have you had mild pain and swelling with redness less than 1 in. (2.5 cm) around a bite or sting for 24 hours or longer? Yes Have you had swollen lymph nodes in your neck, armpit, or groin for 24 hours or longer? If you have answered "No" to the above questions, continue to answer the questions to evaluate your symptoms.
	Yes	Do you know or think you need a tetanus shot?
When to See a Doctor See significance of getting a tetanus shot if you need information to help you answer the question below. Review health risks that may increase the seriousness of your symptoms. Note: If you need a tetanus shot, call your doctor to arrange for the shot as soon as possible. Your need for a tetanus shot depends on the seriousness of your wound and your tetanus shot history. Your doctor may be able to tell you over the telephone if you need a tetanus shot. Call your health professional today if you answer "Yes" to any of the following questions. Yes Are you worried that the bite area has gotten dirty or has germs on it and your last tetanus shot was longer than 5 years ago? Note: Something is dirty if it has dirt, soil, spit, or feces on it. Yes Are you not sure when you had your last tetanus shot? Yes Did you not get the first series of tetanus shots (primary vaccination series)? If you have answered "No" to the above questions, continue to answer the questions to evaluate your symptoms.

Other Symptoms to Watch For

Do you have any of the following symptoms?

• An expanding red rash that has developed within 3 weeks of an insect bite: Go to the topic Tick Bites.
• Symptoms of scabies: Go to the topic Scabies.
• Symptoms of lice: Go to the topic Lice.
• Symptoms that concern you after having traveled to a malaria-infected country in the past 12 months: Go to the topic Malaria.
• A blister or bump on the skin that you are not sure was caused by an insect or spider: Go to the topic Blisters or Skin Changes.
• A rash, but you are unsure if you were bitten or stung: Go to the topic Rash, Age 12 and Older or Rash, Age 11 and Younger.

If a visit to a health professional is not needed immediately, see the Home Treatment section for self-care information.

Common bites and stings

Most bites and stings will heal on their own without a visit to a doctor. There are several things you can do to relieve pain and itching and prevent infection from a bite or sting.

Insect or spider bites or stings or contact with caterpillars

• Move away from the stinging or biting insect. Bees will alert other bees, making them more likely to sting.
• Remain as calm and quiet as possible. Movement increases the spread of venom in the bloodstream.
• If you have been stung by a bee and the stinger is still in the skin, remove the stinger as quickly as possible.
• If you have been stung on the arm or leg, lower the limb at the time of the sting to slow the spread of venom. Hours later, if swelling is present, you can elevate the limb to help reduce swelling.
• After contact with a puss caterpillar, remove broken-off spines by placing cellophane tape or commercial facial peel over the area of the contact and pulling it off.

Relieve pain, itching, and swelling

• Apply an ice pack to a bite or sting for 15 to 20 minutes once an hour for the first 6 hours. When 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. Do not apply ice for longer than 15 to 20 minutes at a time, and do not fall asleep with the ice on your skin.
• Elevate the area of the bite or sting to decrease swelling.
• Try a nonprescription medicine for the relief of itching, redness, and swelling. Be sure to follow the nonprescription medicine precautions.
  • An antihistamine taken by mouth, such as Benadryl or Chlor-Trimeton, may help relieve itching, redness, and swelling. Do not give antihistamines to children younger than 1 year unless directed to do so by your doctor.
  • 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. Note: Do not use the cream on children younger than age 2 unless your doctor tells you to. Do not use in the rectal or vaginal area in children younger than age 12 unless your doctor tells you to.
• After the first 6 hours, if swelling is not present, try applying warmth to the site for comfort.

• Consider a home remedy. Home remedies haven't been proven scientifically, but usually they won't hurt you if you want to try them.

Prevent a skin infection

• Wash the area with soap and water.
• After washing, wipe the area with rubbing alcohol or first-aid antiseptic.
• Trim fingernails to prevent scratching, which can lead to infection.
• Do not break any blisters that develop.
• If a bite becomes irritated, apply an antibiotic ointment, such as bacitracin or polymyxin B sulfate, and cover it with an adhesive bandage. The ointment will keep the bite from sticking to the bandage. Note: Stop using the ointment if the skin under the bandage begins to itch or a rash develops. The ointment may be causing a skin reaction.

For home treatment of lice, scabies, tick bites or bedbugs, see the topics Lice, Scabies, or Tick Bites or information about bedbugs.

Symptoms to Watch For During Home Treatment

Use the Check Your Symptoms section to evaluate your symptoms if any of the following occur during home treatment:

• New symptoms develop.
• Symptoms of a skin infection develop.
• Flu-like symptoms develop.
• Symptoms become more severe or more frequent.

Take the following measures to help prevent bites and stings.

• Apply insect repellent before going into the woods or other areas where you may come in contact with insects. Use insect repellents according to directions, particularly when applying repellent to children.
• Apply repellents safely. Some insect repellents can only be safely applied to clothing rather than skin.
  • Use a lower-concentration repellent on children.
  • Do not put repellent on small children's hands, since they often put their hands in their mouths.
  • Wash the insect repellent off with soap and water after returning indoors.
• Wear light-colored, smooth-finished clothes that cover your body, such as long-sleeved shirts and long pants. Button long sleeves and tuck long pants inside boots. Avoid loose clothes that might entangle a biting or stinging insect. Avoid bright colors. Avoid going barefooted or wearing sandals outdoors. Some outdoor stores may sell clothing treated with a repellant.
• Avoid wearing perfumed lotions, aftershave, or scented hair products during the warm months.
• Take positive steps to manage your surroundings.
  • Always close car windows.
  • Do not put your picnic out until you are ready to eat, and repack picnic food as soon as you are finished serving.
  • Avoid flowering plants.
  • If you have a severe allergic reaction (anaphylaxis) to insect bites or stings, have someone else mow lawns or clip hedges.
• Avoid swatting at insects or flailing your arms around them. Instead, retreat slowly and calmly when insects act threatening.

Additional measures include those to:

• Prevent bee stings (also hornet, wasp, and yellow jacket stings).
• Prevent spider bites.
• Prevent flea bites.
• Prevent bedbug and kissing bug bites.

If you have had a severe allergic reaction (anaphylaxis) to bites or stings in the past:

• Carry an allergy kit prescribed by a doctor. If you don't have one, talk to your doctor about getting one. Learn how and when to use it, and keep it with you at all times.
• Wear a medical identification tag to let others know you have an insect allergy.
• Discuss allergy shots (immunotherapy) with your doctor. Shots may be appropriate to control and prevent your symptoms. For more information, see:

  Should I have allergy shots for allergies to insect stings?

To prepare for your appointment, see the topic Making the Most of Your Appointment

You can help your doctor diagnose and treat your condition by being prepared to answer the following questions:

• What type of insect or spider bit or stung you? Be prepared to describe it.
• When were you bitten or stung? How many times were you bitten or stung? Where on your body were you bitten or stung?
• Have you ever had a severe allergic reaction (anaphylaxis) to a similar bite or sting?
• What are your main symptoms?
• When did your symptoms begin? How have your symptoms developed, progressed, or changed since the bite or sting?
• What home treatment have you tried for the bite or sting? Did it help?
• What prescription or nonprescription medicines have your tried on the bite? Did they help?
• Have you traveled recently?
• Do you have any health risks?

• Abdominal Pain, Age 12 and Older
• Allergic Reaction
• Allergic Rhinitis
• Blisters
• Dealing With Emergencies
• Dizziness: Lightheadedness and Vertigo
• Fever, Age 3 and Younger
• Fever, Age 4 and Older
• Lice
• Lyme Disease
• Nausea and Vomiting, Age 4 and Older
• Rash, Age 11 and Younger
• Rash, Age 12 and Older
• Respiratory Problems, Age 11 and Younger
• Respiratory Problems, Age 12 and Older
• Scabies
• Seizures
• Shock
• Skin Changes
• Swollen Glands and Other Lumps Under the Skin
• Tick Bites
• Vomiting, Age 3 and Younger
• West Nile Virus

Author:	Jan Nissl, RN, BS	Last Updated: February 1, 2008
Medical Review:	William M. Green, MD - Emergency Medicine Sean P. Bush, MD, FACEP - Emergency Medicine and Envenomation Specialist
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