Treatment of bumblebee stings and allergies
This information on bumblebee stings provides guidance for reducing the chance of being stung by a bumblebee and about the possible reaction to a sting and treatment.
1. Bumblebee, honeybee, and wasp stings
Bumblebees are found in the natural environment in many countries. In addition, bumblebees and honeybees are used as pollinators in agricultural and horticultural crops. There are various subspecies with differing appearances including different colours and patterns. In general, bumblebees are larger than honeybees, and more hairy than wasps.
Only bumblebee workers and queens have a stinger, as is the case with honeybees and wasps. Drones cannot sting. The stinger is a weapon for defence. When a bee stings, some venom is injected into the body though the stinger. In humans, this generates a short severe pain that then fades away. Occasionally (in approximately 1% of cases), an allergic reaction against the injected venom develops.
The response to a bumblebee sting can differ per incident.
The stinger of a bumblebee or a wasp has no barbs. This means that the worker or queen can withdraw her stinger, and is able to sting again. A honeybee’s stinger does have barbs. When a honeybee tries to withdraw its stinger, it tears loose from the abdomen, taking the venom gland with it.
2. How to prevent bumblebee stings
Bumblebees rarely sting. When people come into contact with bumblebees, the chance of being stung by a bumblebee can be reduced by avoiding provoking them or making them aggressive. First of all, it is important to be calm when working with bumblebees. Do not wave your arms at the bumblebees, bump the hive, grab or hold the bumblebees, etc.
Also, be aware that bumblebees can react aggressively to smells such as alcohol, perspiration, perfumes, scented soaps, aftershave, and so on. Moreover, rings, bracelets and watches may cause aggressive behaviour (due to the scent of oxidised material between the skin and the jewellery). Bumblebees are attracted to the colour blue, including blue and particularly light blue clothing. Wearing protective clothing can reduce the risk of stings. Bumblebees can sting through clothing.
3. Stung? Reactions and treatments
3.1. Non-allergic, local reaction
Usually a bumblebee sting leads to a non-allergic, local reaction: swelling, itchiness and redness at the site of the sting, lasting only for a couple of hours. This can occur directly after the sting, but more generally it starts after some hours. The swelling or itching may last for hours or even days. In some cases the local reaction may spread somewhat; in that case it usually takes longer for the symptoms to go away. This still counts as a local, non-allergic reaction.
3.1.1. Treatment of a non-allergic, local reaction
Usually medical treatment is not necessary. Some measures can be taken to minimise the local reaction, in particular if the person was stung in a sensitive location, such as near the eyes. As soon as possible after being stung, the person should take an anti-inflammatory (such as aspirin or ibuprofen). Cold compresses should also be applied to the site. In addition, a number of anti-itch ointments are available (e.g. containing diethyl-m-toluamide).
In the rare case of a sting in the mouth or pharynx, the patient should be taken to hospital immediately, because this can result in blocked airways. In the hospital the patient will be given corticosteroids (such as prednisone) and will be kept in for observation.
3.2. Allergic reaction
In about 1% of the population, repeated stings (or in some cases only two or three stings) may lead to an allergic reaction, also called a general allergic reaction, a systemic allergic reaction, or an anaphylactic reaction. Because an allergic reaction involves antibodies formed during a previous exposure to an antigen, it is not possible to have an allergic reaction after the first sting. Allergic reactions usually become evident very soon after the sting (within anywhere from a few seconds to half an hour after the sting).
Allergic reactions are classified in four levels, in order of increasing severity:
Level 1 - itching, redness and swelling (urticaria, hives) over the whole body
Level 2 - level 1 symptoms plus intestinal problems (vomiting, diarrhoea)
Level 3 - level 1 and/or 2 symptoms plus difficulties in breathing and/or a feeling of suffocating
Level 4 - level 1 and/or 2 and/or 3 symptoms plus heart palpitations, fainting, anaphylactic shock (accompanied by dizziness, excessive sweating, and cold shivers)
3.2.1. Treating an allergic reaction
In the event of a fever occurring or a grade 1 reaction, contact a GP. The decision can be made to keep an eye on the situation and see how things go. A period of observation in hospital is desirable, as the reaction may increase progressively over time.
In the event of vomiting, and definitely in the case of grade 3 or 4 symptoms, the victim should be taken to hospital immediately.
If an allergic reaction occurs, administration of a prescription-strength antihistamine (such as clemastine) is useful. The antihistamine reduces the swelling caused by the histamine in the venom. Sometimes corticosteroids (such as DAF/Dexamethasone) are prescribed. In the case of level 3 or 4 reactions, it is necessary to administer adrenaline first. Adrenaline stimulates the heart, constricts the blood vessels, and opens the airways. Adrenaline can be self-administered by means of an adrenaline auto-injector (such as an EpiPen or Jext). Adrenaline auto-injectors are only available by prescription, for instance if the patient has already had an allergic reaction to a bumblebee sting. Depending on local legislation, an adrenaline auto-injector may also be available at companies which work with bumblebees.
3.3. Toxic reactions
Toxic reactions only occur when the victim is stung dozens of times in a brief period. General allergic reactions can occur in the nervous or circulatory system, such as cardiac arrhythmia or difficulties with breathing. In this case as well, the victim should be taken to hospital for treatment and observation.
In addition to a severe, level 4 allergic reaction, hyperventilation, perhaps as a result of shock, may also cause unconsciousness. In such cases it is also necessary to call the emergency medical services immediately.
4. Increased risk
Persons that use certain medicines (beta-blockers) and pregnant women are at increased risk when allergic reactions occur after a bumblebee sting.
5. Living with a bumblebee allergy
If you have had an allergic reaction once, you will not necessarily have an allergic reaction to the next sting. If you had a level 1 or 2 reaction in particular, the chance is small. Reactions to bumblebee stings may differ in each case. These days it is possible to take a test using purified bumblebee venom to determine whether you will have an allergic reaction the next time you are stung. It is also possible to use the purified venom for a hyposensitisation treatment.
Immunotherapy with bumblebee venom does not necessarily protect patients with honeybee or wasp venom allergy. Immunotherapy with honeybee venom does not necessarily protect patients with bumblebee allergy. This treatment is intended to desensitise the body to bumblebee venom. If you do not wish to undergo hyposensitisation treatment, you can obtain a prescription for an adrenaline auto-injector (such as an EpiPen or Jext) from your doctor. This can be carried with you and is used to inject epinephrine into the thigh in the case of a sting.
Tests and treatments are available at the Allergology department of the RdGG (Dr de Groot) at the Diakonessehuis location in Voorburg.
6. Information for doctors
Detailed information regarding medical treatment of allergic reactions is available from Koppert on request.
For further information, contact an allergologist or a doctor of internal medicine.
De Groot, H. Allergie voor insecten, Huisarts en Wetenschap 2002; 45 (7): 362-7.
De Groot, H. Allergy to bumble bees. Curr Opin Allergy Clin Immunol 2006; 6: 294-7.
A printed poster showing the images is available from Koppert. This poster is also available as a download (URL).
Tip: Make a note on the poster of the contact information for seeking medical assistance and emergency medical treatment.
This information is intended as an education resource only and should not be used for diagnosing or treating a health problem as it is not a substitute for medical care. If you have or suspect you may have a health problem, please consult medical care.