Allergy and intolerance
IgE antilichamen sesam
Antibodies against sesame protein; shows whether the immune system is sensitive to sesame, not whether you get symptoms from it.
Everything about this testWhat it measures
Sesame seed is eaten as whole seeds, for example on bread, and is used in sesame paste (tahini), sesame oil, hummus, crackers and Asian dishes. As a result, sesame is often hidden in food, and sometimes also in cosmetics, medicines and pet food; sesame must be listed as an allergen on food packaging. This test measures the amount of IgE antibodies against the proteins in sesame in the blood, in kU/l. The body only makes these antibodies after it has previously been in contact with the allergen; this is called sensitization.
- Sensitization to sesame: the body has made IgE antibodies against sesame
- Support in working out a suspected allergy to sesame, together with the history of the symptoms
- Support in finding the cause of a reaction to a meal in which sesame may be hidden, such as hummus or bread with seeds
High
A value above the cut-off means that you have IgE antibodies against sesame: sensitization. That is not the same as an allergy. A sesame allergy can cause symptoms ranging from hives and swelling to abdominal symptoms, shortness of breath and a severe allergic reaction (anaphylaxis). According to Stichting Voedselallergie, there are cross-reactions between sesame and poppy seed, hazelnut and rye, and people with a sesame allergy also have a chance of an allergy to Brazil nut, almond, walnut or pistachio. A positive result can therefore also come from antibodies against a related food. The level of the value says little about how severe a reaction would be.
Low
A value below the cut-off means that no IgE antibodies against this allergen were found. An IgE-mediated allergy to this allergen is then much less likely, although it is not completely ruled out. Symptoms can also come from another allergen that was not tested, or have a non-allergic cause.
If your result is abnormal
The GP mainly looks at the history: which symptoms, when and where they occur and after contact with what. With a positive result and matching symptoms, advice usually follows to limit contact with the allergen and, if needed, medication. With a severe reaction, in case of doubt or with symptoms that are not brought under control this way, a referral to an allergist, pediatrician, ENT specialist or lung specialist may follow.
Reliability
A positive IgE result shows sensitization, not allergy: it only says that there are antibodies, not that you get symptoms from them. The Dutch medical specialists' guideline (FMS) on upper airway allergy says this literally and recommends choosing a test for single allergens based on the history of the symptoms; for food allergy, the FMS guideline on food challenge testing calls the history of the symptoms the cornerstone of diagnosis and a food challenge in hospital the gold standard. The result therefore only means something if it fits when, where and after contact with what you get symptoms. A positive result without symptoms is not treated.
Limitations
- Sensitization without symptoms is common; the result can only be interpreted together with the history of the symptoms.
- Related allergens can recognize each other's antibodies (cross-reaction), for example pollen and nuts or fruit; a positive result then does not mean that this particular allergen causes the symptoms.
- The test measures all proteins from the allergen source together; testing for individual proteins (components) can say more in case of doubt.
- Laboratories use different measurement methods and cut-off values; results from different labs cannot be compared one to one.
How common is this
How often sesame allergy occurs in the Netherlands is not known. According to Stichting Voedselallergie, sesame allergy is increasing in Europe, and more and more sesame is being eaten.
Who is this useful for
Useful with a clear reaction shortly after eating sesame or a dish that may contain sesame, such as hummus, tahini, bread with seeds or an Asian dish. If you reacted to a meal with several possible allergens, the result can help determine which food is suspected, according to the Dutch medical specialists' guideline (FMS). In people who eat sesame normally without symptoms, the test adds nothing.
Sources
- NVKC, allesovertesten.nl: Allergie (RAST)
- FMS Richtlijnendatabase: Allergie van de bovenste luchtwegen, module Aanvullende diagnostiek
- FMS Richtlijnendatabase: Voedselprovocatie, module Plaatsbepaling diagnostiek voedselallergie
- Thuisarts.nl: Ik heb allergie
- NHG-Standaard Voedselovergevoeligheid en coeliakie (M47)
- Stichting Voedselallergie: Sesam
- Thuisarts.nl: Ik denk dat ik niet tegen bepaald voedsel kan
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