Allergy – Insect Sting

Treatment At Home

For most insect stings, home care is all that is necessary.fghghg

  • If insects are on or around you, remain calm.
    • Gently brush any insects from your skin.
    • Quietly leave the area as quickly as you can.
  • If the stinger is still lodged in the skin, as it usually is after honeybee stings, it should be removed promptly.
    • You can do this by scraping the site with a credit card or similar device, perpendicular to the skin. A fingernail can be used.
    • Pinching the stinger to pull it out is not advised, because this may inject more venom.
  • Control local swelling
    • Elevate the part of the body where the sting is located.
    • Apply ice to the area of the sting.
    • If the sting is on the hands or feet where rings or other tight-fitting jewelry is worn, these should be removed immediately before swelling develops, to avoid any compression of the blood supply to these areas.
  • Control pain: Ibuprofen (Advil) or acetaminophen (Tylenol) is usually sufficient to relieve pain.
  • Treat the itch
    • Take an antihistamine pill, such as diphenhydramine (Benadryl). This helps counteract one of the mediators of the reaction and will help control itching. Diphenhydramine is available without a prescription. Caution – this medication makes most people too drowsy to drive or operate machinery safely. It can be taken every 6 hours for the first few days, until the swelling begins to improve.
    • Hydrocortisone cream, available over-the-counter, can be applied to the site of the insect sting to relieve itching.
    • A paste of baking soda or salt and water, rubbed on the skin, may provide relief.
    • An over-the-counter lotion such as Calamine can help.
    • If a blister develops at the site, keep the area clean but do not break the blister.

Do not be alarmed if the reaction takes 2-5 days to heal. Continue treatment until all symptoms are gone.

If you have symptoms of anaphylaxis, here’s what you can do while waiting for the ambulance:

  • Try to stay calm.
  • Remove yourself from the area where the insects are.
  • Take an antihistamine (1-2 tablets or capsules of diphenhydramine [Benadryl]) if you can swallow without difficulty.
  • If you are wheezing or having difficulty breathing, use an inhaled bronchodilator such as albuterol (Proventil) or epinephrine (Primatene Mist) if one is available. These inhaled medications dilate the airway.
  • If you are feeling light-headed or faint, lie down and raise your legs higher than your head to help blood flow to your brain.
  • If you have been given an epinephrine kit, inject yourself as you have been instructed. The kit provides a premeasured dose of epinephrine, a prescription drug that rapidly reverses the most serious symptoms (see Follow-up).
  • Bystanders should administer CPR to a person who becomes unconscious and stops breathing or does not have a pulse.
  • If at all possible, you or your companion should be prepared to tell medical personnel which medications you have taken today, which you usually take, and any known allergies.

MEDICAL TREATMENT

The top priority for the medical team is ensuring that your breathing and blood pressure are protected.

  • If you are having difficulty breathing, you may be given oxygen via a tube in your nose or by face mask.
  • In cases of severe respiratory distress, you may be put on a mechanical ventilator. This is temporary until the effects of the reaction abate.
  • If your blood pressure is too low, an IV line will be placed.
  • You may be given saline solution through the IV to boost your blood pressure.
  • You may be given medication if needed to ease your breathing and/or increase your blood pressure.

Several insects belonging to the class Hymenoptera are capable of injecting venom into humans and animals. These insects include honeybees, bumble bees, hornets, wasps, yellow jackets, and fire ants.

OVERVIEW

  • All of these insects are currently found in the United States as well as in most other land areas of the globe. Their venom, which they use to kill or paralyze other insects, is composed of proteins and other substances. It is proteins in the venom that cause allergic reactions in people.
  • Not everyone is allergic to stinging insect venom. In people who are not allergic, the venom causes only redness, itching, and mild pain and swelling at the site of the bite. Cleaning the area and applying ice are enough to relieve the symptoms.
  • Even people who are allergic to the venom usually have only mild symptoms, although the swelling may extend beyond the area right around the sting. People with allergy may have a more serious reaction, called an anaphylactic reaction.

Insect Sting Allergy Causes

An allergic reaction occurs when the immune system of the body overreacts to an “invader” such as insect venom (the allergen). This overreaction is sometimes referred to as a hypersensitivity reaction.

The white blood cells produce an antibody to the protein in the venom.

  • The allergic reaction occurs when the antibody, known as immunoglobulin E, or IgE, comes in contact with the protein, either at the first sting or later.
  • IgE promotes release from certain cells of chemicals and hormones called “mediators.” Histamine is an example of a mediator.
  • It is the effects of these mediators on organs and other cells that cause the symptoms of the allergic reaction.

Ants, bees, and wasps have a stinger or venom sac and gland on their tail that they use to inject venom.

  • Several stings may occur, particularly if you accidentally disturb a hive or nest.
  • This is particularly true with fire ants and so-called Africanized bees.
  • Africanized bees are the result of breeding of domesticated and wild honeybees in Africa that resulted in a very aggressive honeybee. The venom of these bees is no more potent than that of normal honeybees, but their aggressive nature increases the likelihood that they will swarm and sting you many times, sometimes hundreds of times.
  • Such a large number of stings may result in serious reactions or death, even if you are not allergic to bee venom.
  • If you are allergic to the venom, then you may have an allergic reaction from even a single sting. This is called an anaphylactic reaction. It can be dangerous, even life threatening.

An anaphylactic reaction does not usually occur on the first sting.

  • The immune system makes the antibody at the first sting and stores it on special cells until the next sting. This is called “sensitization.”
  • At the first sting, therefore, the body does not have antibodies specific to the venom.
  • Only on a second or later sting can the body mount a major defense against the venom.
  • This is when a life-threatening anaphylactic reaction may occur.
  • Anaphylactic reactions are rare, and do not happen to every person who is stung by an insect.
  • When an anaphylactic reaction seems to occur on the very first sting, probably the person was stung before without realizing it.

Insect venom is used to treat certain medical conditions.

  • In Chinese herbal medicine, the venoms of various insects in this class are used either as direct stings (as a treatment for arthritis and other chronic diseases) or are applied to the skin or the eyes.
  • Such apiotherapy (the medicinal use of honeybee products) may result in an anaphylactic reaction in people who are allergic.
  • Allergy shots given by an allergy specialist also contain venom but are specifically designed to be given to allergic people to reduce their sensitivity to the allergen.