Allergy and intolerance
IgE antilichamen wespengif
Antibodies against wasp venom; useful after a generalized allergic reaction to a wasp sting, not as a test without such a reaction.
Everything about this testWhat it measures
When a wasp stings, it injects venom into the skin; a wasp can sting several times and does not leave a stinger behind. Wasps are mainly active in late summer, around food, drinks and waste. In most people a sting only causes pain, redness and swelling around the sting. After a previous sting, the body can make IgE antibodies against proteins in the venom; this is called sensitization. With an allergy, a next sting can then cause a reaction in the whole body. This test measures the amount of IgE antibodies against the venom of the common wasp in the blood, in kU/l.
- Sensitization to wasp venom: the body has made IgE antibodies against the venom of the wasp
- Support for the question of whether a previous generalized (systemic) reaction after a sting fits an allergy to wasp venom, together with the history of the reaction
- Together with the test for bee venom: help with the question of whether a reaction was caused by a wasp or a bee
High
A value above the cut-off means that you have IgE antibodies against wasp venom: sensitization. That is not the same as an allergy. If you have had a reaction in the whole body after a wasp sting, such as itching or hives all over the skin, swollen lips or tongue, shortness of breath, dizziness or fainting, a positive result fits an allergy to wasp venom. Without such a reaction, a positive result is common and says little: in an Austrian study, 23 to 67 percent of people who had never had a reaction to a sting still had antibodies against bee or wasp venom, more often the higher the total IgE was. The level of the value does not predict how severe a next reaction will be.
Low
A value below the cut-off means that no IgE antibodies against wasp venom were found. An allergy to wasp venom is then less likely, but after a clear generalized reaction it is not ruled out: in the first weeks after a sting the value may not yet be measurable, and in some people with a real allergy the blood test finds no antibodies. The allergist can then repeat the test or investigate further, for example with a skin test. A negative result does not change what you do in case of a new severe reaction.
If your result is abnormal
With a severe reaction after a sting, such as shortness of breath, a swollen tongue or throat, dizziness or fainting, call 112 immediately; a result of this test does not change that. After a generalized reaction, the GP usually refers you to an allergist, and the GP and allergist decide together with you, based on the reaction and the results, about an adrenaline auto-injector for emergencies and about venom immunotherapy. According to the European guideline, this immunotherapy is the only treatment that prevents new generalized reactions to a sting.
Reliability
A positive IgE result shows sensitization, not allergy. With insect venom this matters even more: antibodies without a previous reaction are common and poorly predict whether you will react to a next sting. The European Academy of Allergy and Clinical Immunology (EAACI) therefore only recommends testing after a generalized (systemic) reaction to a sting, not after only a large swelling around the sting and not in people who have never had a reaction. After such a reaction, the result together with the history of the reaction and, if needed, a skin test forms the basis for the decision about treatment.
Limitations
- Antibodies without a previous generalized reaction are common, especially in people with a high total IgE; the result can only be interpreted together with the history of the reaction.
- Antibodies against sugar groups that are present in both bee venom and wasp venom can make both tests positive; it then remains unclear which venom you really react to. Testing for individual venom proteins (components) can sort this out.
- In the first weeks after a sting the value may not yet be measurable; a negative result shortly after a reaction is therefore repeated later.
- The level of the value does not say how severe a next reaction will be.
How common is this
According to the European guideline, up to 7.5 percent of adults and up to 3.4 percent of children ever have a generalized allergic reaction to an insect sting; in northern and central Europe this mainly concerns wasps and honeybees. Antibodies against insect venom without symptoms are much more common than an allergy.
Who is this useful for
Useful after a generalized (systemic) allergic reaction to a wasp sting: symptoms in places other than the sting, such as itching or hives all over the body, swollen lips or tongue, shortness of breath, dizziness or fainting. Not useful after only pain, redness or a large swelling around the sting, and not if you have never had a reaction: a positive result then says little. If you are not sure whether it was a wasp or a bee, both venoms are usually tested; a wasp does not leave a stinger behind.
Downsides and risks
- A positive result without a previous reaction can cause unnecessary fear of stings, and lead to an adrenaline auto-injector or further testing that is not needed.
- A negative result after a clear generalized reaction can give false reassurance; with a new severe reaction, calling 112 immediately remains necessary.
Sources
- Thuisarts.nl: Ik ben gestoken door een insect
- FMS Richtlijnendatabase: Anafylaxie bij kinderen, module Adrenaline bij anafylaxie bij kinderen (tabel indicaties adrenaline-auto-injector)
- Biló BM, Ruëff F, Mosbech H, et al. (EAACI Interest Group on Insect Venom Hypersensitivity). Diagnosis of Hymenoptera venom allergy. Allergy 2005;60(11):1339-1349
- Sturm GJ, Varga EM, Roberts G, et al. EAACI guidelines on allergen immunotherapy: Hymenoptera venom allergy. Allergy 2018;73(4):744-764
- Sturm GJ, Schuster C, Kranzelbinder B, et al. Asymptomatic sensitization to hymenoptera venom is related to total immunoglobulin E levels. International Archives of Allergy and Immunology 2009;148(3):261-264
Always discuss an abnormal result with your GP. If a result is strongly abnormal, we try to reach you as soon as possible. Read your result yourself as well and contact your GP if in doubt. A test does not make a diagnosis. Read more about risks and results