Bees and wasps are equipped with venomous stingers as a defense mechanism; wasps are often predatory and can sting to kill prey, while bees sting purely for defensive purposes because they feed on the nectar of plants. Bees and wasps both frequently sting humans that they see as threatening. These insects are equipped with a venom that is composed of different protein and peptide antigens, or substances that elicit an immune response, as well as other chemicals. Bee venom and wasp venom are different in composition, but the ingredients are similar and have basically the same physiological effects on humans. Bees can only sting a person one time, because their stingers have large barbs that get stuck in human skin. When the bee tries to remove its stinger, the stinger detaches from the bee’s abdomen, along with the bee’s venom sac. After this happens, the bee will die. A wasp, on the other hand, can sting a person multiple times, as its stinger has smaller barbs that do not catch in human skin. Each time the wasp thrusts its stinger, a little more venom is injected. Bee and wasp venom introduced to the body may have a different reaction in different individuals based on how sensitive their immune systems are to the substances present in the venom.
Everybody’s immune system generates at least a localized reaction to the potent antigens, with some minor swelling at the site of the sting. Stings are painful due to neurotransmitters and chemicals present in bee and wasp venom that stimulate pain receptors and increase the frequency of nerve signal transmission, making the sting more painful than it would be without venom. The pain is described as a burning or sharp pain. There is usually some redness, swelling and possibly itching around the sting site. This reaction is due to a chemical called histamine being released in the skin due to the presence of antigens in the bee or wasp venom. The symptoms of a localized skin reaction to a bee or wasp sting usually last for a few hours. In the case of a bee sting, the stinger and venom sac may be visible protruding from the skin. Most people who are stung by a bee or wasp have this type of minor reaction.
Some people, however, have a more severe localized reaction, indicating that their immune systems are more sensitized to the antigen components of the insect venom. In these cases, the swelling and discomfort is more severe and can last for about a week. Contrary to popular belief, having a reaction like this does not mean that you are more likely to have a severe allergic reaction to a bee or wasp sting in the future. Upon future exposure to bee or wasp venom, most people become desensitized and actually experience less of a reaction. However, some people may notice no difference in the severity of the reaction, and some people may experience a severe allergic reaction when they have never had one before.
A small minority of people are severely allergic to bee or wasp stings. This type of systemic allergic reaction, called anaphylaxis, is a medical emergency. Symptoms of anaphylaxis include difficulty breathing, a rash or hives in parts of the body that were not stung by a bee or wasp, throat or tongue swelling, a fast heart rate and weak pulse, nausea, gastrointestinal upset, dizziness and loss of consciousness. Anaphylaxis can be life threatening for two reasons. First, a systemic allergic reaction can cause the airways to swell, leading to asphyxiation, or suffocation. Second, a condition called anaphylactic shock can result in which blood pressure drops dramatically. This dangerously low blood pressure can lead to a person losing consciousness, and if blood pressure drops low enough, a person’s heart can stop because it does not have enough blood to pump to keep functioning. Symptoms of anaphylaxis do not have to occur immediately after a person is stung by a bee or wasp; it may take several hours for the reaction to start, although symptoms usually appear within an hour of being stung. Anyone who has been stung should be monitored. The vast majority of the time, if a severe allergic reaction does not occur within five hours of being stung, it is not likely that an allergic reaction will occur.
Although individual bees can only sting once, a person who is caught in a swarm and is stung multiple times may have a more severe reaction than someone who was only stung once because more venom is introduced systemically. Symptoms of multiple bee stings, besides the typical skin reactions, include nausea, diarrhea, vomiting, fever, headache, dizziness, lightheadedness and, in severe cases, convulsions. Anyone who has been stung many times by a swarm of bees should seek medical attention.