Bees and Wasps

Bees and Wasps 2560 1627 Federico de la Roca Pinzón

Bees and wasps belong to the insect order Hymenoptera. These get their name from their characteristic membranous wings. In the case of bees and wasps, there are 2 pairs of wings, the later ones being a little smaller than the previous ones. From an allergological point of view, their importance lies in the fact that they are responsible for the vast majority of allergic reactions due to insect bites.

Are bees and wasps dangerous insects?

No, both bees and the different species of wasps that inhabit the Iberian Peninsula are not considered dangerous insects. Although they can adopt an aggressive attitude, this usually only happens when they feel threatened, especially if we get too close to their nests.

Why do bees and wasps sting?

The bite of these insects is a defense measure rather than an attack. In many cases it can be a deterrent sting to prevent us from approaching the nest. If this measure does not work, the attitude can be more aggressive, thus leading to multiple bites by more than one insect at a time. This is what happens with wasps, which can sting more than once.

In the case of bees, they can only sting once since after the sting they die. This is because when the stinger is left at the site of the sting, it detaches from the insect, tearing its abdomen. After the sting, the bee dies by evisceration.

Are bee and wasp stings common?

Sí, al ser insectos que conviven en nuestro entorno las picaduras de abejas y avispas son frecuentes. Se estima que al menos el 56 al 94% de la población adulta ha sido picado alguna vez a lo largo de su vida por alguno de estos insectos

What types of reactions does the bite of these insects produce?

Reactions from bee and wasp stings can be divided according to the type of reaction between allergic and non-allergic, and according to the intensity of the reaction in local or systemic.

Most of the reactions that occur after the sting of a bee or wasp is a non-allergic reaction, which in most cases is a local reaction. These reactions are due to the components of the venom itself. An inflammatory reaction is observed at the sting site, characterized by edema (swelling), redness, and pain. The inflammation does not usually exceed 10 cm in diameter and usually subsides between 24 and 48 hours after the sting.

In the case of allergic reactions, these are rare, and only occur in people who have previously developed an immune response to the poison. These reactions are not due exclusively to the compounds of the venom but to the immune response that they produce in the person who suffers the sting.

Allergic reactions can be local or systemic depending on the intensity of the immune response to the poison. Symptoms of allergic local reactions are similar to non-allergic ones. If the edema and redness (inflammatory reaction) extend over 10 cm in diameter, covers 2 joints and persists for more than 24-48 hours, it is considered an extensive local reaction. In general, local reactions, even in allergic patients, are not severe.

Systemic reactions are rare, but they are the most severe. After the sting, in addition to the local inflammatory reaction, patients allergic to the venom may experience skin symptoms such as itching and “wheals” all over the body (acute urticaria), abdominal pain with nausea and vomiting, respiratory distress, low blood pressure (hypotension) and loss of consciousness (syncope). The presence of hypotension or syncope after a bee or wasp sting indicates that the patient is suffering from anaphylactic shock and requires immediate emergency attention since her life is in danger.

How does an allergic reaction differ from one that is not?

In general, the difference is established by the intensity of the symptoms. If it is limited to a local inflammatory reaction at the site of the sting that does not exceed 10 cm in diameter, it is very likely that we are facing a non-allergic local reaction. If the inflammation extends more than 10 cm in diameter or if it includes any other symptoms such as generalized itching, abdominal discomfort, respiratory distress or loss of consciousness, the probability that the patient is allergic is very high.

How do I know if I’ve been bitten by a bee or a wasp?

It is common for patients to have been stung by an insect, but cannot identify it, either because they did not see it at the time of the sting or because they cannot differentiate a bee from a wasp (or any other insect). If at the site of the sting the stinger is observed it is very likely that the insect responsible is a bee. Bees die after the sting so a bee can only sting once. If several bites are suffered at once and none of them shows the stinger, it is very likely that the sting is due to wasps.

How do I know if I am allergic to bee venom or wasp venom?

Whenever an allergic reaction to bee or wasp venom is suspected, an allergy specialist should be consulted. The symptoms that were had after the sting provide a lot of information about the type of reaction presented. If the symptoms are compatible with an allergic reaction, specific blood tests are carried out, as well as skin tests with the venoms of bees and wasps. These last tests are not exempt from risk, so they should only be carried out by experienced personnel and in facilities suitable for them. They are not tests that are performed routinely in outpatient clinic. As a whole, the information on the reaction after the sting, the values ​​of the blood tests and the results of the skin tests allow to diagnose those patients allergic to the venom of bees or wasps of those who are not.

If I am allergic to wasp venom, am I also allergic to bee venom?

No, generally not. Although some of the venom components of wasp venom are similar to that of bees, it is rare for a person allergic to wasp venom to be allergic to bee venom as well. It is more common to be allergic to two different species of wasps.

How are local sting reactions treated?

The first thing is to remove the stinger, if any. In bees, the stinger is attached to the sac that contains the venom, so even if the insect is dead, the sac can continue to release venom and introduce it into the skin through the stinger. Next, it is advisable to wash the bite sting and thus avoid the risk of future infections. Depending on the intensity of the symptoms, a topical corticosteroid cream and local cold (ice) can be applied. Oral antihistamines and corticosteroids are recommended if the discomfort is very intense or in case of extensive reactions. Massaging the sting area should be avoided, as well as the application of local heat.

How are systemic sting reactions treated?

In addition to general measures, such as removing the stinger (if any) and washing the sting site, the most effective measure to control and stop the progress of a severe allergic reaction to bee and wasp venom is the use of adrenaline. It is for this reason that every allergic patient should have an “emergency kit”. These kits must contain at least 2 adrenaline auto-injectors, antihistamines and oral corticosteroids.

In case of doubt, if a patient allergic to bee or wasp venom is stung, they should use the adrenaline autoinjector. The side effects produced by adrenaline are minimal, while the benefits are maximum. Adrenaline auto-injectors can save lives.

How can I prevent bee and wasp stings?

The best measure to avoid bee and wasp stings is to stay away from their nests. As we have mentioned before, these insects bite in most cases because they feel threatened and the sting is nothing more than a defence mechanism.

Most of the stings occur in the months of April to October. These are the months in which these insects increase their activity. Both bees and wasps are attracted to bright colours, floral fragrances, water surfaces, and fresh foods. Therefore, if we go out into the countryside in these months, we should avoid wearing bright colours, using colognes or fruity perfumes, not leaving sugary drinks such as juices or soft drinks exposed, avoiding riverbanks and dodge the fields with abundant flowers. If despite all these recommendations we are in close contact with a bee or wasp, we should not make sudden or rapid movements, nor should we try to kill the insect (especially if it is resting on any part of our body). The insect will most likely walk away on its own without causing any harm.

At ClinicAL ​​we hope to have provided information on the reactions caused by bee and wasp stings that are quite frequent in these months

Any doubt?

Contact with us

Dr Federico de la Roca
Allergy Specialist