Allergy and intolerance
IgE antilichamen rund
Antibodies against cattle allergen; shows whether the immune system is sensitive to cows, not whether you get symptoms from them.
Everything about this testWhat it measures
Cattle spread allergens through their dander and hair. In the barn, these allergens get into the air, and via clothing and hair they also end up in the home. This test measures the amount of IgE antibodies against cattle dander 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. An allergy to cow's milk or beef is something else and is not measured with this test.
- Sensitization to cattle: the body has made IgE antibodies against cattle allergen
- A lead with symptoms of the nose, eyes or airways that occur in a cow barn or when working with livestock
High
A value above the cut-off means that you have IgE antibodies against cattle allergen: sensitization. That is not the same as an allergy. In people who get symptoms in the barn or when caring for or milking cows, such as sneezing, a blocked or runny nose, itchy or watery eyes, coughing or shortness of breath, a positive result fits an allergy to cattle. Some cattle allergens are similar to those of other mammals, such as cat, dog and horse; antibodies against those animals can therefore also give a positive result with this test. In people without such symptoms, a positive result only means that the antibodies are there; no treatment follows.
Low
A value below the cut-off means that no IgE antibodies against cattle allergen were found. An allergy to cattle is then less likely, but not ruled out: in a German study of 42 farmers with symptoms caused by cows, the standard blood test was negative in about 1 in 3, while more extensive laboratory testing still found antibodies against cow allergen. Symptoms in the barn can also come from dust, molds in hay or straw, or irritating substances such as ammonia.
If your result is abnormal
The GP mainly looks at the history: whether the symptoms occur in the barn and get better on days off and during holidays. With a positive result and matching symptoms, the advice is mainly about limiting contact with cows and barn dust; with symptoms caused by work, the occupational health doctor can look at measures at work. With asthma or symptoms that are not brought under control with medication, a referral to a lung specialist or allergist 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
Allergy to cattle mainly occurs in people who work with cows, such as dairy farmers. The Dutch medical specialists' guideline (FMS) on work-related asthma lists animal proteins among the allergens that can cause asthma from work, and livestock farming among the sectors where people are exposed to airway irritants at work. Sensitization is more common than the allergy itself.
Who is this useful for
Useful with symptoms of the nose, eyes, skin or airways that occur when working with cows, in the barn or during milking, or with contact with the clothing of someone who works with cows. This also applies to veterinarians and others who work with livestock. In people without such symptoms, the test adds nothing: sensitization without symptoms is not a disease and is not treated.
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
- FMS Richtlijnendatabase: Werkgerelateerd astma, module Diagnostiek
- Heutelbeck AR, Junghans C, Esselmann H, et al. Exposure to allergens of different cattle breeds and their relevance in occupational allergy. Int Arch Occup Environ Health 2009;82:1123-1131
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