Allergy and intolerance
IgE antilichamen kokosnoot
Antibodies against coconut protein; shows whether the immune system is sensitive to coconut, not whether you get symptoms from it.
Everything about this testWhat it measures
Botanically, the coconut is not a nut: according to Stichting Voedselallergie, it is a fruit. Coconut is also not among the nuts that must be listed as an allergen on food packaging. Coconut is found in, among other things, coconut milk, grated coconut, cookies, sweets and Asian dishes. This test measures the amount of IgE antibodies against the proteins in coconut 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. Skin symptoms from soap or shampoo containing substances from coconut are usually a contact allergy; that is not IgE-mediated and is not measured with this test.
- Sensitization to coconut: the body has made IgE antibodies against coconut
- Support in working out a suspected allergy to coconut, together with the history of the symptoms
High
A value above the cut-off means that you have IgE antibodies against coconut: sensitization. That is not the same as an allergy. Symptoms that fit an allergy are itching or swelling in the mouth and throat, hives, vomiting or shortness of breath, shortly after eating or drinking coconut. Coconut allergy is uncommon, and a nut allergy does not mean that you also react to coconut. If you eat coconut without symptoms, a positive result does not mean an allergy. 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
Coconut allergy is rare; no Dutch figures have been found. According to Stichting Voedselallergie, nut allergy occurs in 1 to 2 in 100 people in the Netherlands, but coconut is not counted among them.
Who is this useful for
Useful with a clear reaction shortly after eating or drinking coconut, such as itching or swelling in the mouth and throat, hives, vomiting or shortness of breath. In people with a nut allergy who eat coconut without symptoms, the test adds nothing. The test is not suitable for skin symptoms from care products containing substances from coconut.
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: Noten
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