Theodore Freeman, MD
David B Golden, MD
Anna M Feldweg, MD
OVERVIEW — Being stung by a bee, wasp, hornet, or yellow jacket can be both painful and scary. Some people have serious or even life-threatening reactions to stings, requiring quick treatment.
This article will review the most common types of stings, reactions to stings, and recommended treatments. More detailed information about stings is available by subscription. (See “Bee, yellow jacket, wasp, and other Hymenoptera stings: Reaction types and acute management”.)
INSECT TYPES — The insects that cause the most serious sting reactions include the following:
- Honeybees (picture 1) and bumblebees
- Yellow jackets (picture 2), yellow hornets, white faced hornets, and paper wasps (picture 3)
- Fire ants (picture 4), harvester ants, bulldog ants, and jack jumper ants. Fire ants are discussed separately (see “Patient information: Fire ants”).
INSECT STING REACTION — After being stung, you should remove the stinger from your skin as soon as possible to prevent any more venom from being released into the skin. However, all the venom is released from the stinger within the first few seconds, so this is only helpful if done quickly. You do not need to use any special technique (eg, flicking or scraping) to get the stinger out.
Most people who are stung by an insect will develop a local reaction (an area of swelling and redness). Some people will also develop a severe allergic reaction, called anaphylaxis.
Local reaction — Immediately after being stung, most people have:
- Sharp or burning pain
- Skin swelling and redness (picture 5)
The swelling and pain usually improve within a few hours.
Approximately 10 percent of people develop severe redness and swelling after a sting; this is called a large local reaction. The area may become large (4 inches or 10 cm) over 1 to 2 days, then slowly resolve over 5 to 10 days.
Having a large local reaction does not mean that you will have a severe allergic reaction (anaphylaxis) if you are stung again. Only about 5 to 10 percent of people who have a large local reaction will have anaphylaxis if stung in the future. If you have a large local reaction, talk to your doctor or nurse to determine what steps, if any, you need to take if you are stung again.
Local reaction treatment — To reduce pain and swelling after an insect sting, you can try the following:
- Apply a cold compress (a cold, damp washcloth or damp cloth wrapped around an ice pack) to the area.
- If you develop itching, you can take a nonprescription antihistamine, such as cetirizine (Zyrtec®).
- A pain reliever, such as ibuprofen (sold as Advil, Motrin, and store brands), may help reduce pain.
If nonprescription treatments do not help or your pain or swelling gets worse, call your doctor or nurse.
Severe allergic reaction — Insect stings are a common cause of severe allergic reactions, called anaphylaxis. You can have an anaphylactic reaction the first time you are stung. Symptoms of an anaphylactic reaction usually develop quickly, and include:
- Skin symptoms, such as hives, redness, or swelling of skin away from the area that was stung (for example, the face or lips may swell after being stung on the hand)
- Belly cramps, nausea, vomiting, or diarrhea
- Hoarse voice, shortness of breath, and difficulty breathing
- Lightheadedness, dizziness, passing out
Severe allergic reaction treatment — Severe allergic reactions are a medical emergency that can lead to death if not treated quickly. If you develop any symptoms of anaphylaxis, you need to get emergency care as soon as possible. When possible, ask someone else to call for emergency care (call 911 in the United States).
Do not drive yourself to the hospital and do not ask someone else to drive you. Calling 911 is safer than driving for two reasons:
- You can get treatment from the paramedics as soon as the ambulance arrives. If you drive to the hospital, you cannot get treatment until you arrive in the emergency department.
- Since dangerous complications may occur (eg, you stop breathing) on the way to the hospital, paramedics are trained to treat you. (See “Patient information: Anaphylaxis treatment and prevention”.)
The first and most important treatment for a severe allergic reaction is a shot of epinephrine. Epinephrine is available by prescription in prefilled syringes, called epinephrine autoinjectors. Instructions for using epinephrine are available in a separate article. (See “Patient information: Use of an epinephrine autoinjector”.)
AM I ALLERGIC TO STINGS? — If you had a severe reaction (anaphylaxis) after being stung, you should make an appointment to see an allergy specialist. At this visit, the allergist will:
- Try to determine if you are allergic to stings
- Help you decide if you need allergy shots (called immunotherapy) to reduce your risk of anaphylaxis in the future
- Teach you how and when to use an epinephrine autoinjector
Allergy testing — Testing can be done to determine if you are allergic to insect stings. Blood and skin tests are available, and both are needed in some cases. (See “Diagnosis of Hymenoptera venom allergy”.)
If allergy testing shows that you are allergic to insect stings, there is a good chance that you will have a serious allergic reaction (anaphylaxis) if you are stung again. Allergy shots can greatly reduce the risk of anaphylaxis.
Allergy shots (immunotherapy) — Allergy shots, also called venom immunotherapy, can reduce your chance of having a serious or life-threatening reaction to a sting. When you are stung by an insect, the stinger injects venom into your skin, which causes the allergic reaction. Allergy shots usually contain purified venom. The first few allergy shots contain very small amounts of venom, and the amount is gradually increased until you can tolerate the amount of venom in two or more stings without having allergic symptoms.
Allergy shots are often recommended if you had:
- A serious allergic reaction (anaphylaxis) after being stung, AND
- Allergy testing shows that you are allergic to bee, wasp, yellow jacket, or hornet venom
Allergy shots are usually given in an allergist’s office one to three times per week for a few months, and then once per month for at least three years. (See “Hymenoptera venom immunotherapy: Efficacy, indications, and mechanism of action”.)
Some people continue to get allergy shots for three to five years while other people get them for longer. Most experts recommend that you continue getting allergy shots indefinitely if:
- You had a life-threatening reaction to a past sting
- You have a reaction to the allergy shot since this is a sign that you are very sensitive to the venom
- You are so fearful of having a severe allergic reaction that you cannot enjoy normal outdoor activities
As a result of immunotherapy, your risk of having a serious allergic reaction after a sting becomes much lower. You should still carry an epinephrine autoinjector. (See “Hymenoptera venom immunotherapy: Determining duration of therapy”.)
Epinephrine — Epinephrine, sometimes called adrenaline, is a medicine that can treat the symptoms of a serious allergic reaction. Epinephrine is available in pre-filled syringes so that you can give yourself a shot, if needed. If you had anaphylaxis after an insect sting in the past, you should always carry at least one epinephrine autoinjector (even in the winter).
However, one or even two injections of epinephrine may not be enough to stop a life-threatening reaction. This is why it is important to talk to an allergist about allergy shots if you have had a serious allergic reaction after a sting. You should also seek emergency medical care after using an epinephrine autoinjector, because the symptoms of allergic reactions sometimes come back after initially improving.
AVOIDING STINGS — Bees and wasps that are away from their nest are not aggressive and only sting when threatened (after being hit, stepped on, or swatted). Wearing brightly colored clothing or perfume does not increase the risk of being stung. Wearing white or light-colored clothing may reduce the chance of being attacked if you are near a nest.
When eating outside, keep food and drinks covered and wipe up food and drink spills quickly. Watch for yellow jackets inside drink containers. Do not walk outside without shoes.
If you find a wasp nest near your home, do not try to get rid of the nest yourself. Instead, call a pest control professional. If you have a sting allergy, avoid activities that may disturb a nest, such as mowing the lawn or pruning a hedge.
If a stinging insect is near, slowly back away and do not flail your arms. If you are being swarmed or stung, cover your mouth and nose with your hand and run inside a building or an enclosed vehicle.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem.
This article will be updated as needed every four months on our web site (www.uptodate.com/patients).
Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.
Patient Level Information:
Patient information: Fire ants
Patient information: Anaphylaxis treatment and prevention
Patient information: Use of an epinephrine autoinjector
Professional Level Information:
Bee, yellow jacket, wasp, and other Hymenoptera stings: Reaction types and acute management
Diagnosis of Hymenoptera venom allergy
Entomology and control of imported fire ants
Hymenoptera venom immunotherapy: Determining duration of therapy
Hymenoptera venom immunotherapy: Efficacy, indications, and mechanism of action
Hymenoptera venom immunotherapy: Technical issues, protocols, adverse effects, and monitoring
Scorpion stings in the United States and Mexico
Stings of imported fire ants: Clinical manifestations, diagnosis, and treatment
The following organizations also provide reliable health information.
- National Library of Medicine
- American Academy of Allergy, Asthma, & Immunology
- Severino M, Bonadonna P, Passalacqua G. Large local reactions from stinging insects: from epidemiology to management. Curr Opin Allergy Clin Immunol 2009; 9:334.
- Freeman TM. Clinical practice. Hypersensitivity to hymenoptera stings. N Engl J Med 2004; 351:1978.
- Biló BM, Rueff F, Mosbech H, et al. Diagnosis of Hymenoptera venom allergy. Allergy 2005; 60:1339.
- Bonifazi F, Jutel M, Biló BM, et al. Prevention and treatment of hymenoptera venom allergy: guidelines for clinical practice. Allergy 2005; 60:1459.