Although only about forty deaths from stinging insect reactions are reported every year, the figure is probably far higher. Also, perhaps surprisingly, it is double that of the number of deaths caused by poisonous snakes. Moreover, it is estimated that for every death that is reported there are thousands of severe and near-fatal reactions. The majority of these are caused by stings from a variety of common, mostly flying insects that belong to the order that scientists call the Hymenoptera. This large group includes yellow jackets, honeybees, hornets, wasps, and bumblebees. And of this group, more people die each year from bee stings than from all other insect attacks combined. Besides having membranous wings, all Hymenoptera possess venom-producing glands, located at the tip of the abdomen, through which they sting their victims to introduce the venom.
The Hymenoptera family also includes the ferocious imported fire ants that are found mostly in the southern United States; their sting, as the name suggests, feels like a sharp flash of fire. Distinct from its airborne relatives, however, these crawling insects (they do not fly despite the presence of wings) first bite their victims to lock on to them and then pivot their bodies to savagely deliver multiple stings.
As a rule, Hymenoptera sting only when frightened, although the so-called African killer bees, which have recently been migrating steadily upward from Mexico into the southern United States, are responsible for unprovoked attacks. Contrary to a popular misconception and despite what the name implies, the venom of killer bees is no more dangerous than that of its less aggressive relatives. Mild reactions to Hymenoptera stings, which consist of redness, slight swelling, tenderness, and mild pain at the sting sites, are not believed to be allergic in nature. Such reactions generally last no more than a few hours before subsiding completely without the development of any complications.
On the other hand, more extensive local reactions, such as those progressing to involve an entire arm or leg, as well as severe systemic reactions are felt to be allergy related. Two venom enzymes, phospho-lipase A and hyaluronidase, are believed to be the major allergens responsible for most allergic reactions to the bee family. It is also important to know that an allergy to one member of the Hymenoptera family may result in cross-allergies to other members of the group, and therefore if you have become sensitized to the yellow jacket, you may also develop a severe reaction to a wasp sting. Atopic individuals those with a personal or family history of asthma, hay fever, or eczema are more likely to develop true insect sting allergies than nonatopic persons. Severe swelling may be accompanied by intense itching, nausea, vomiting, abdominal cramps, dizziness, and wheezing. In extreme cases victims may suffer shock, a precipitous drop in blood pressure, and complete respiratory failure. These events often occur within thirty minutes of the sting. Because children tend to be less severely affected by systemic insect stings, most fatal reactions occur in adults.
Commonsense outdoor measures for protecting against stings include not wearing brightly colored clothing, flowery prints, or shiny jewelry; avoiding scented lotions, colognes, and hair sprays; and avoiding sweets, syrupy drinks, fruit juices, and sodas. In general, Hymenoptera are less attracted to white, green, and khaki colors. Obviously, wear your shoes and socks at all times, and never touch, sit, or step on anything outdoors without first looking. Commercial insect repellents are of little value against Hymenoptera and should not be relied on.
The best treatment for local reactions is rather simple: Remove the stinger and reduce the swelling. You can often get the stinger out by simply catching one of the barbs and scraping it out with the edge of a credit card or with your fingernail. This is particularly important if the sting is from a honeybee, which typically leaves its stinger behind. Don't use tweezers, and avoid any squeezing motions that might push more venom into the sting site.
Once you have removed the stinger, immediately elevate the affected area and apply ice. Additionally, if possible, within the first few minutes apply a small paste consisting of a few droplets of water and a commercial meat tenderizer. The protein-attacking enzyme papain, contained in the meat tenderizer, may help to reduce the swelling and pain, but only if it is used very soon after the sting. In uncomplicated cases swelling usually goes down in a day or so.
If the reaction is more severe and persistent, however, see your doctor. You may need a prescription for a topical corticosteroid cream and perhaps even an oral antihistamine such as chlorpheniramine (Chlor-Trimeton) or diphenhydramine (Benadryl) to reduce the inflammation and ease the symptoms. Acetaminophen (such as Tylenol) or ibuprofen (Advil) may also be helpful for reducing symptoms.
Severe allergic reactions require emergency care, which generally consists of the immediate injection of epinephrine (Adrenalin) and sometimes even the use of blood-pressure-elevating medications and respiratory assistance. Because of the tendency for symptoms to progress rapidly in these instances, time is of the essence. As a result, antihistamines and corticosteroid pills are of little value for emergency care since they begin working more slowly.
If you have a history of severe reactions to any Hymenoptera stings, you would do well to be evaluated by an allergist. Intradermal testing and RAST blood tests may be used to determine specific allergies to venom or venom components, although of the two methods, skin testing is more sensitive. Whatever method is selected, however, testing is usually postponed until at least six weeks after the last sting attack. This is to allow IgE antibody levels, which are depleted for several weeks following an attack, to return to normal.
Immunotherapy or desensitization shots (similar to the kinds used to treat hay fever allergies) have been shown to impressively reduce the risk of potentially life-threatening reactions to Hymenoptera stings from 60 percent to as low as 5 percent. Desensitization is generally achieved by using specific venom proteins, the major allergenic culprits in most Hymenoptera problems. In the case of fire ants, however, since both the venom and the body proteins have been found to be allergenic, desensitization requires the use of whole body extracts of the bug.
In general, immunotherapy is reserved only for those who have a definite history of a systemic reaction to Hymenoptera. Because of the possibility of cross-allergenicity, many doctors choose to desensitize their patients with mixed-venom extracts. Shots are usually given about twice weekly for three months, and booster shots are generally given thereafter for the next five years to maintain adequate levels of immunity. A more rapid immunotherapy regimen is sometimes chosen, consisting of an entire series of increasing doses of venom administered over a several-hour period and followed by a series of four booster shots at periodic intervals. Many authorities recommend that maintenance venom immunotherapy be continued indefinitely.
Regardless of the precise method of desensitization, because protection is not absolute it is still advisable for anyone at risk of a life-threatening reaction to carry an emergency kit at all times outdoors (for example, EpiPen, Ana-Guard, or Ana-Kit). These kits usually contain antihistamine tablets, a tourniquet, a syringe, and most important, epinephrine ampules for self-injection. Careful attention should be paid to the package expiration date in order to replace the kit as needed. And since epinephrine may be affected by sunlight, the kit should be stored away from direct exposure. The user should of course be thoroughly familiar with the contents and their uses before heading out for a barbecue, picnic, or jaunt in the woods.
